Wheat

Wheat is a grass extensively cultivated for its seed, a cereal grain which is a worldwide staple meals.[1][2][3] The many species of wheat together make up the genus Triticum; essentially the most broadly grown is common wheat (T. aestivum). The archaeological record means that wheat was once first cultivated in the regions of the Fertile Crescent round 9600 BCE. Botanically, the wheat kernel is a type of fruit referred to as a caryopsis.

Wheat is grown on more land area than some other food crop (220.4 million hectares, 2014).[4] World trade in wheat is bigger than for all other crops combined.[5] In 2016, world production of wheat was once 749 million tonnes,[6] making it the second one most-produced cereal after maize.[6][7] Since 1960, world production of wheat and other grain plants has tripled and is expected to grow further through the center of the 21st century.[8] Global demand for wheat is increasing due to the unique viscoelastic and adhesive homes of gluten proteins, which facilitate the production of processed meals, whose intake is increasing as a result of the global industrialization procedure and the westernization of the nutrition.[9][10]

Wheat is crucial source of carbohydrates.[9] Globally, it’s the main supply of vegetal protein in human meals, having a protein content material of about 13%, which is slightly high compared to different major cereals [11] but quite low in protein high quality for supplying very important amino acids.[12][13] When eaten as the whole grain, wheat is a source of a couple of vitamins and dietary fiber.[9]

In a small part of the overall population, gluten – the major a part of wheat protein – can cause coeliac disease, noncoeliac gluten sensitivity, gluten ataxia, and dermatitis herpetiformis.[14]
Origin and history
Cultivation and repeated harvesting and sowing of the grains of wild grasses led to the creation of home lines, as mutant forms (‘sports activities’) of wheat had been preferentially chosen by means of farmers. In domesticated wheat, grains are larger, and the seeds (within the spikelets) remain hooked up to the ear by means of a toughened rachis all through harvesting.[15] In wild traces, a extra fragile rachis permits the ear to simply shatter and disperse the spikelets.[16] Selection for these traits via farmers may no longer were deliberately meant, however simply have befell as a result of these characteristics made gathering the seeds more straightforward; nevertheless such ‘incidental’ variety used to be the most important a part of crop domestication. As the characteristics that toughen wheat as a food source additionally contain the loss of the plant’s herbal seed dispersal mechanisms, extremely domesticated lines of wheat can’t live on in the wild.

Cultivation of wheat started to spread beyond the Fertile Crescent after about 8000 BCE. Jared Diamond traces the unfold of cultivated emmer wheat beginning in the Fertile Crescent sometime ahead of 8800 BCE. Archaeological research of wild emmer signifies that it was once first cultivated in the southern Levant, with unearths dating again so far as 9600 BCE.[17][18] Genetic research of untamed einkorn wheat means that it was first grown within the Karacadag Mountains in southeastern Turkey. Dated archeological stays of einkorn wheat in settlement sites near this area, including the ones at Abu Hureyra in Syria, counsel the domestication of einkorn close to the Karacadag Mountain Range.[19] With the anomalous exception of two grains from Iraq ed-Dubb, the earliest carbon-14 date for einkorn wheat remains at Abu Hureyra is 7800 to 7500 years BCE.[20]
Remains of harvested emmer from a number of websites near the Karacadag Range have been dated to between 8600 (at Cayonu) and 8400 BCE (Abu Hureyra), that is, within the Neolithic length. With the exception of Iraq ed-Dubb, the earliest carbon-14 dated remains of domesticated emmer wheat have been discovered within the earliest ranges of Tell Aswad, in the Damascus basin, close to Mount Hermon in Syria. These stays had been dated through Willem van Zeist and his assistant Johanna Bakker-Heeres to 8800 BCE. They additionally concluded that the settlers of Tell Aswad didn’t broaden this form of emmer themselves, but brought the domesticated grains with them from an as yet unidentified location in other places.[21]
The cultivation of emmer reached Greece, Cyprus and Indian subcontinent by 6500 BCE, Egypt shortly after 6000 BCE, and Germany and Spain by way of 5000 BCE.[22] “The early Egyptians have been developers of bread and the usage of the oven and developed baking into one of the first large-scale food production industries.” [23] By 3000 BCE, wheat had reached the British Isles and Scandinavia. A millennium later it reached China.
The oldest evidence for hexaploid wheat has been confirmed through DNA research of wheat seeds, courting to around 6400-6200 BCE, recovered from Çatalhöyük.[24] The first identifiable bread wheat (Triticum aestivum) with enough gluten for yeasted breads has been identified using DNA analysis in samples from a granary dating to approximately 1350 BCE at Assiros in Macedonia.[25]
From Asia, wheat endured to unfold across Europe. In the British Isles, wheat straw (thatch) used to be used for roofing within the Bronze Age, and was in not unusual use until the late 19th century.[26]
Farming ways
Technological advances in soil preparation and seed placement at planting time, use of crop rotation[clarification needed] and fertilizers to give a boost to plant enlargement, and advances in harvesting methods have all blended to advertise wheat as a viable crop. When the usage of seed drills changed broadcasting sowing of seed within the 18th century, any other great increase in productivity occurred.
Yields of pure wheat in line with unit house larger as methods of crop rotation had been carried out to lengthy cultivated land, and the use of fertilizers turned into standard. Improved agricultural husbandry has more lately incorporated threshing machines and reaping machines (the ‘combine harvester’), tractor-drawn cultivators and planters, and higher types (see Green Revolution and Norin 10 wheat). Great expansion of wheat manufacturing happened as new arable land was farmed within the Americas and Australia in the 19th and 20th centuries.
Physiology
Leaves emerge from the shoot apical meristem in a telescoping fashion until the transition to reproduction ie. flowering.[27] The ultimate leaf produced by way of a wheat plant is known as the flag leaf. It is denser and has a better photosynthetic charge than other leaves, to provide carbohydrate to the creating ear. In temperate countries the flag leaf, in conjunction with the second and 3rd absolute best leaf at the plant, supply nearly all of carbohydrate in the grain and their condition is paramount to yield formation.[28][29] Wheat is atypical among plants in having more stomata at the upper (adaxial) facet of the leaf, than at the below (abaxial) facet.[30] It has been theorised that this might be an effect of it having been domesticated and cultivated longer than any other plant.[31] Winter wheat usually produces as much as 15 leaves per shoot and spring wheat up to nine[32] and wintry weather plants will have up to 35 tillers (shoots) according to plant (relying on cultivar).[33]
Wheat roots are some of the private of arable plants, extending as some distance down as 2m.[34] While the roots of a wheat plant are growing, the plant additionally accumulates an power retailer in its stem, within the form of fructans,[35] which helps the plant to yield underneath drought and disease pressure,[36] however it has been observed that there is a trade-off between root expansion and stem non-structural carbohydrate reserves.[37] Root expansion might be prioritised in drought-adapted crops, whilst stem non-structural carbohydrate is prioritised in types evolved for countries the place disease is a larger issue. Depending on variety, wheat could also be awned or now not awned. Producing awns incurs a cost in grain quantity,[38] however wheat awns photosynthesise more water-use-efficiently than their leaves,[39] so awns are much more widespread in types of wheat grown in hot drought-prone international locations than the ones usually noticed in temperate international locations. For this reason, awned sorts could grow to be more extensively grown because of local weather alternate. In Europe, on the other hand, a decline in climate resilience of wheat has been noticed.[40]
Genetics
Wheat genetics is extra sophisticated than that of most other domesticated species. Some wheat species are diploid, with two sets of chromosomes, however many are solid polyploids, with four sets of chromosomes (tetraploid) or six (hexaploid).[41]
Einkorn wheat (T. monococcum) is diploid (AA, two enhances of seven chromosomes, 2n=14).[3]
Most tetraploid wheats (e.g. emmer and durum wheat) are derived from wild emmer, T. dicoccoides. Wild emmer is itself the results of a hybridization between two diploid wild grasses, T. urartu and a wild goatgrass akin to Aegilops searsii or Ae. speltoides. The unknown grass hasn’t ever been identified amongst now surviving wild grasses, but the closest residing relative is Aegilops speltoides.[42] The hybridization that formed wild emmer (AABB) befell in the wild, long earlier than domestication,[41] and was pushed via natural variety.
Hexaploid wheats developed in farmers’ fields. Either domesticated emmer or durum wheat hybridized with yet some other wild diploid grass (Aegilops tauschii) to make the hexaploid wheats, spelt wheat and bread wheat.[41] These have 3 sets of paired chromosomes, thrice as many as in diploid wheat.
The presence of positive versions of wheat genes has been necessary for crop yields. Apart from mutant versions of genes decided on in antiquity right through domestication, there was more moderen deliberate number of alleles that impact expansion characteristics. Genes for the ‘dwarfing’ trait, first used by Japanese wheat breeders to produce short-stalked wheat, have had a huge impact on wheat yields international, and have been main elements within the good fortune of the Green Revolution in Mexico and Asia, an initiative led by Norman Borlaug. Dwarfing genes enable the carbon that is fixed within the plant all over photosynthesis to be diverted against seed manufacturing, they usually also assist prevent the issue of accommodation. ‘Lodging’ happens when an ear stalk falls over within the wind and rots at the ground, and heavy nitrogenous fertilization of wheat makes the grass grow taller and turn into extra at risk of this drawback. By 1997, 81% of the growing international’s wheat area used to be planted to semi-dwarf wheats, giving each greater yields and better response to nitrogenous fertilizer.
Wild grasses within the genus Triticum and similar genera, and grasses comparable to rye were a source of many disease-resistance traits for cultivated wheat breeding since the 1930s.[43]
Heterosis, or hybrid vigor (as within the acquainted F1 hybrids of maize), happens in commonplace (hexaploid) wheat, but it is tricky to provide seed of hybrid cultivars on a industrial scale (as is finished with maize) as a result of wheat vegetation are very best and typically self-pollinate. Commercial hybrid wheat seed has been produced using chemical hybridizing brokers; those chemicals selectively intrude with pollen development, or naturally occurring cytoplasmic male sterility systems. Hybrid wheat has been a restricted business luck in Europe (particularly France), the United States and South Africa.[44] F1 hybrid wheat cultivars must not be confused with the standard means of breeding inbred wheat cultivars by means of crossing two strains using hand emasculation, then selfing or inbreeding the progeny many (ten or extra) generations sooner than free up picks are identified to be released as a wide range or cultivar.
Synthetic hexaploids made through crossing the wild goatgrass wheat ancestor Aegilops tauschii and quite a lot of durum wheats are now being deployed, and those increase the genetic variety of cultivated wheats.[45][46][47]
Stomata (or leaf pores) are curious about both uptake of carbon dioxide gas from the ambience and water vapor losses from the leaf due to water transpiration. Basic physiological investigation of these gas alternate processes has yielded valuable carbon isotope based strategies which are used for breeding wheat types with stepped forward water-use potency. These varieties can make stronger crop productiveness in rain-fed dry-land wheat farms.[48]
In 2010, a team of UK scientists funded via BBSRC introduced they’d decoded the wheat genome for the primary time (95% of the genome of a lot of wheat referred to as Chinese Spring line 42).[49] This genome was launched in a basic structure for scientists and plant breeders to use however used to be now not a completely annotated collection which was once reported in probably the most media.[50]
On 29 November 2012, an necessarily complete gene set of bread wheat was once revealed.[51] Random shotgun libraries of general DNA and cDNA from the T. aestivum cv. Chinese Spring (CS42) had been sequenced in Roche 454 pyrosequencer the usage of GS FLX Titanium and GS FLX+ platforms to generate 85 Gb of sequence (220 million reads), equivalent to 5X genome coverage and known between 94,000 and 96,000 genes.[51]
This collection data supplies direct get entry to to about 96,000 genes, relying on orthologous gene sets from other cereals. and represents an crucial step in opposition to a scientific figuring out of biology and engineering the cereal crop for precious traits. Its implications in cereal genetics and breeding comprises the exam of genome variation, affiliation mapping using herbal populations, acting vast crosses and alien introgression, learning the expression and nucleotide polymorphism in transcriptomes, examining inhabitants genetics and evolutionary biology, and studying the epigenetic modifications. Moreover, the supply of large-scale genetic markers generated via NGS generation will facilitate trait mapping and make marker-assisted breeding a lot more feasible.[52]
Moreover, the knowledge no longer most effective facilitate in decoding the complex phenomena comparable to heterosis and epigenetics, it may also allow breeders to are expecting which fragment of a chromosome is derived from which guardian in the progeny line, thereby recognizing crossover occasions going on in each progeny line and placing markers on genetic and physical maps without ambiguity. In due direction, this will likely help in introducing explicit chromosomal segments from one cultivar to every other. Besides, the researchers had known various classes of genes participating in power manufacturing, metabolism and enlargement that had been most certainly connected with crop yield, which can now be utilized for the advance of transgenic wheat. Thus complete genome series of wheat and the availability of thousands of SNPs will inevitably permit the breeders to stride in opposition to figuring out novel characteristics, providing biological wisdom and empowering biodiversity-based breeding.[52]
Plant breeding
In conventional agricultural methods wheat populations incessantly encompass landraces, casual farmer-maintained populations that frequently handle top ranges of morphological diversity. Although landraces of wheat are now not grown in Europe and North America, they remain important somewhere else. The origins of formal wheat breeding lie within the 19th century, when single line sorts have been created through choice of seed from a single plant famous to have desired houses. Modern wheat breeding developed in the first years of the 20th century and was carefully related to the improvement of Mendelian genetics. The same old method of breeding inbred wheat cultivars is by crossing two strains using hand emasculation, then selfing or inbreeding the progeny. Selections are identified (shown to have the genes answerable for the varietal variations) ten or more generations before liberate as a wide range or cultivar.[53]
The main breeding goals include high grain yield, good high quality, disease and bug resistance and tolerance to abiotic stresses, together with mineral, moisture and warmth tolerance. The primary diseases in temperate environments include the following, arranged in a rough order in their importance from cooler to warmer climates: eyespot, Stagonospora nodorum blotch (also known as glume blotch), yellow or stripe rust, powdery mould, Septoria tritici blotch (on occasion known as leaf blotch), brown or leaf rust, Fusarium head blight, tan spot and stem rust. In tropical areas, spot blotch (also known as Helminthosporium leaf blight) could also be vital.
Wheat has additionally been the topic of mutation breeding, with the usage of gamma, x-rays, ultraviolet light, and every so often harsh chemicals. The forms of wheat created thru these methods are within the hundreds (going as far back as 1960), more of them being created in upper populated nations corresponding to China.[54] Bread wheat with prime grain iron and zinc content used to be advanced via gamma radiation breeding.[55] Modern bread wheat varieties had been cross-bred to comprise better quantities of gluten,[56] which presents important advantages for bettering the quality of breads and pastas from a functional viewpoint.[57] Gluten is favored for its distinctive viscoelastic houses.[57] It provides elasticity to dough and is responsible for dough’s gas-retaining properties.[57]

International wheat breeding is led by way of CIMMYT in Mexico. ICARDA is some other major public sector international wheat breeder, but it was once compelled to relocate from Syria within the Syrian Civil War. The global file wheat yield is about 17t/ha, reached in New Zealand in 2017.[58] A challenge in the United Kingdom, led through Rothamsted Research has aimed to raise wheat yields in the country to 20t/ha by 2020, but in 2018 the UK report stood at 16t/ha, and the common yield used to be simply 8t/ha.[59][60]
Hybrid wheat
Because wheat self-pollinates, creating hybrid types is terribly labor-intensive; the prime price of hybrid wheat seed relative to its average benefits have stored farmers from adopting them widely[61][62] despite just about 90 years of effort.[63] F1 hybrid wheat cultivars should not be at a loss for words with wheat cultivars deriving from usual plant breeding. Heterosis or hybrid vigor (as within the familiar F1 hybrids of maize) occurs in common (hexaploid) wheat, however it’s tricky to provide seed of hybrid cultivars on a industrial scale as is completed with maize as a result of wheat vegetation are very best within the botanical sense, that means they have both female and male portions, and most often self-pollinate.[53] Commercial hybrid wheat seed has been produced the use of chemical hybridizing agents, plant growth regulators that selectively interfere with pollen development, or naturally occurring cytoplasmic male sterility techniques. Hybrid wheat has been a restricted commercial luck in Europe (in particular France), the United States and South Africa.[64]
Hulled as opposed to free-threshing wheat
The 4 wild species of wheat, together with the domesticated varieties einkorn,[65] emmer[66] and spelt,[67] have hulls. This extra primitive morphology (in evolutionary terms) consists of toughened glumes that tightly enclose the grains, and (in domesticated wheats) a semi-brittle rachis that breaks simply on threshing. The result is that after threshed, the wheat ear breaks up into spikelets. To obtain the grain, additional processing, such as milling or pounding, is needed to take away the hulls or husks. In contrast, in free-threshing (or naked) bureaucracy comparable to durum wheat and common wheat, the glumes are fragile and the rachis difficult. On threshing, the chaff breaks up, liberating the grains. Hulled wheats are frequently stored as spikelets for the reason that toughened glumes give just right coverage towards pests of saved grain.[65]
Naming
Further data: Taxonomy of wheat
There are many botanical classification programs used for wheat species, discussed in a separate article on wheat taxonomy. The name of a wheat species from one information source may not be the name of a wheat species in another.

Within a species, wheat cultivars are further labeled by way of wheat breeders and farmers in relation to:
Growing season, equivalent to iciness wheat vs. spring wheat.[68]
Protein content material. Bread wheat protein content levels from 10% in some comfortable wheats with prime starch contents, to 15% in exhausting wheats.
The quality of the wheat protein gluten. This protein can resolve the suitability of a wheat to a particular dish. A Strong and elastic gluten found in bread wheats allows dough to entice carbon dioxide during leavening, however elastic gluten interferes with the rolling of pasta into skinny sheets. The gluten protein in durum wheats used for pasta is powerful however no longer elastic.
Grain color (pink, white or amber). Many wheat types are reddish-brown due to phenolic compounds provide within the bran layer which might be remodeled to pigments via browning enzymes. White wheats have a lower content material of phenolics and browning enzymes, and are in most cases much less astringent in taste than crimson wheats. The yellowish color of durum wheat and semolina flour made from it is because of a carotenoid pigment known as lutein, which can also be oxidized to a drab shape by means of enzymes provide within the grain.
Major cultivated species of wheat
Hexaploid species
Common wheat or bread wheat (T. aestivum) – A hexaploid species that’s the most widely cultivated on the earth.
Spelt (T. spelta) – Another hexaploid species cultivated in limited amounts.[quantify] Spelt is sometimes regarded as a subspecies[by whom?] of the carefully related species common wheat (T. aestivum), during which case its botanical name is considered to be T. aestivum ssp. spelta.
Tetraploid species
Durum (T. durum) – A tetraploid form of wheat broadly used today, and the second one most widely cultivated wheat.
Emmer (T. dicoccon) – A tetraploid species, cultivated in precedent days but now not in common use.
Khorasan (T. turgidum ssp. turanicum, also called T. turanicum) is a tetraploid wheat species. It is an ancient grain kind; Khorasan refers to a ancient area in modern day Afghanistan and the northeast of Iran. This grain is twice the dimensions of modern-day wheat and is known for its wealthy nutty flavor.
Diploid species
Einkorn (T. monococcum) – A diploid species with wild and cultivated variants. Domesticated concurrently emmer wheat.
Classes used in North America
The named categories of wheat in English are more or less the same in Canada as in the USA, as broadly the similar industrial cash crop strains will also be found in each.
The classes used in the United States are : [69][70]
Durum – Very onerous, translucent, light-colored grain used to make semolina flour for pasta & bulghur; excessive in protein, particularly, gluten protein.
Hard Red Spring – Hard, brownish, high-protein wheat used for bread and tough baked items. Bread Flour and high-gluten flours are recurrently produced from arduous purple spring wheat. It is essentially traded at the Minneapolis Grain Exchange.
Hard Red Winter – Hard, brownish, mellow high-protein wheat used for bread, onerous baked goods and as an adjunct in different flours to extend protein in pastry flour for pie crusts. Some manufacturers of unbleached all-purpose flours are often constituted of hard purple winter wheat by myself. It is primarily traded at the Kansas City Board of Trade. One selection is referred to as “turkey crimson wheat”, and was once dropped at Kansas by Mennonite immigrants from Russia.[71]
Soft Red Winter – Soft, low-protein wheat used for desserts, pie crusts, biscuits, and desserts. Cake flour, pastry flour, and some self-rising flours with baking powder and salt added, for instance, are created from comfortable red winter wheat. It is primarily traded at the Chicago Board of Trade.
Hard White – Hard, light-colored, opaque, chalky, medium-protein wheat planted in dry, temperate spaces. Used for bread and brewing.
Soft White – Soft, light-colored, very low protein wheat grown in temperate wet spaces. Used for pie crusts and pastry. Pastry flour, for instance, is every now and then comprised of cushy white iciness wheat.
Red wheats would possibly want bleaching; therefore, white wheats normally command higher prices than purple wheats on the commodities market.
As a food
Raw wheat can also be floor into flour or, the usage of arduous durum wheat most effective, may also be ground into semolina; germinated and dried creating malt; beaten or lower into cracked wheat; parboiled (or steamed), dried, crushed and de-branned into bulgur often referred to as groats.[citation needed] If the uncooked wheat is damaged into parts at the mill, as is usually executed, the outer husk or bran can be utilized a number of ways
Wheat is a big aspect in such meals as bread, porridge, crackers, biscuits, Muesli, pancakes, pasta and noodles, pies, pastries, pizza, polenta and semolina, truffles, cookies, cakes, rolls, doughnuts, gravy, beer, vodka, boza (a fermented beverage), and breakfast cereals.[72]
In manufacturing wheat merchandise, gluten is efficacious to impart viscoelastic functional qualities in dough,[73] enabling the preparation of various processed foods similar to breads, noodles, and pasta that facilitate wheat intake.[74][9]
Nutrition
In 100 grams, wheat supplies 327 kilocalories and is a wealthy supply (20% or extra of the Daily Value, DV) of a couple of essential vitamins, reminiscent of protein, nutritional fiber, manganese, phosphorus and niacin (table). Several B nutrients and different dietary minerals are in important content. Wheat is 13% water, 71% carbohydrates, and 1.5% fats. Its 13% protein content material is mostly gluten (75-80% of the protein in wheat).[73]
Wheat proteins have a low high quality for human nutrition, according to the new protein quality approach (DIAAS) promoted by means of the Food and Agriculture Organization.[13][75] Though they include good enough quantities of the opposite very important amino acids, a minimum of for adults, wheat proteins are poor within the very important amino acid, lysine.[9][76] Because the proteins present in the wheat endosperm (gluten proteins) are particularly poor in lysine, white flours are extra deficient in lysine compared with complete grains.[9] Significant efforts in plant breeding are being made to increase lysine-rich wheat sorts, without luck as of 2017.[77] Supplementation with proteins from different meals assets (principally legumes) is usually used to atone for this deficiency,[12] for the reason that limitation of a single very important amino acid reasons the others to wreck down and become excreted, which is particularly necessary throughout the period of growth.[9]
100 g (3.5 oz.) of exhausting pink iciness wheat comprise about 12.6 g (0.44 oz) of protein, 1.five g (zero.053 oz.) of general fat, 71 g (2.five oz.) of carbohydrate (by difference), 12.2 g (zero.43 oz.) of nutritional fiber, and 3.2 mg (0.00011 oz) of iron (17% of the daily requirement); the same weight of laborious red spring wheat comprises about 15.four g (zero.54 oz) of protein, 1.nine g (0.067 oz.) of overall fat, 68 g (2.4 oz.) of carbohydrate (by way of difference), 12.2 g (0.43 oz) of dietary fiber, and 3.6 mg (zero.00013 ounces) of iron (20% of the day by day requirement).[82]
Worldwide intake
Wheat is grown on more than 218,000,000 hectares (540,000,000 acres),[83] a bigger space than for another crop. World business in wheat is larger than for all different crops blended. With rice, wheat is the sector’s maximum appreciated staple meals. It is a major nutrition component as a result of the wheat plant’s agronomic adaptability having the ability to develop from close to arctic regions to equator, from sea level to plains of Tibet, roughly four,000 m (13,000 feet) above sea level. In addition to agronomic adaptability, wheat provides ease of grain storage and simplicity of converting grain into flour for making fit to be eaten, palatable, interesting and satisfying meals. Wheat is crucial supply of carbohydrate in a majority of nations.[citation needed]
The most common kinds of wheat are white and crimson wheat. However, other natural varieties of wheat exist. Other commercially minor but nutritionally promising species of naturally advanced wheat species come with black, yellow and blue wheat.[5][84][85]
Health results
Consumed worldwide through billions of other folks, wheat is a vital meals for human nutrition, particularly the least bit evolved countries the place wheat products are primary meals.[1][9] When eaten as the whole grain, wheat is a wholesome meals supply of more than one nutrients and dietary fiber really helpful for kids and adults, in numerous day by day servings containing plenty of meals that meet complete grain-rich criteria.[9][74][86][87] Dietary fiber may also help folks really feel complete and therefore help with a wholesome weight.[88] Further, wheat is a significant source for natural and biofortified nutrient supplementation, including dietary fiber, protein and nutritional minerals.[89]
Manufacturers of meals containing wheat as a whole grain in specified quantities are allowed a well being declare for advertising and marketing purposes in the United States, declaring: “low fats diets wealthy in fiber-containing grain merchandise, fruits, and greens would possibly reduce the risk of a few forms of most cancers, a disease associated with many components” and “diets low in saturated fats and ldl cholesterol and rich in end result, vegetables, and grain merchandise that contain some sorts of nutritional fiber, in particular soluble fiber, might reduce the risk of center disease, a disease related to many factors”.[90][91] The scientific opinion of the European Food Safety Authority (EFSA) related to health claims on intestine well being/bowel function, weight keep watch over, blood glucose/insulin levels, weight control, blood ldl cholesterol, satiety, glycaemic index, digestive serve as and cardiovascular well being is “that the meals constituent, entire grain, (…) isn’t sufficiently characterized with regards to the claimed health results” and “that a motive and effect relationship can’t be established between the consumption of whole grain and the claimed effects regarded as in this opinion.”[74][92]

Concerns
In genetically inclined other people, gluten – a significant part of wheat protein – can trigger coeliac disease.[73][93] Coeliac illness impacts about 1% of the general population in evolved nations.[94][93] There is evidence that most cases stay undiagnosed and untreated.[93] The simplest known effective treatment is a strict lifelong gluten-free nutrition.[93]
While coeliac illness is caused by means of a response to wheat proteins, it’s not the same as a wheat allergy.[94][93] Other diseases triggered through eating wheat are non-coeliac gluten sensitivity,[94][14] which is estimated to impact zero.5% to 13% of the general inhabitants.[95] gluten ataxia and dermatitis herpetiformis.[14]
It has been speculated that FODMAPs present in wheat (basically fructans) are the reason for non-coeliac gluten sensitivity. As of 2019, evaluations have concluded that FODMAPs simplest give an explanation for positive gastrointestinal symptoms, akin to bloating, however not the extra-digestive signs that individuals with non-coeliac gluten sensitivity may expand, comparable to neurological disorders, fibromyalgia, psychological disturbances, and dermatitis.[96][97][98]
Other proteins present in wheat called amylase-trypsin inhibitors (ATIs) have been known as the imaginable activator of the innate immune system in coeliac illness and non-coeliac gluten sensitivity.[98][97] ATIs are a part of the plant’s natural defense towards bugs and might cause toll-like receptor 4 (TLR4)-mediated intestinal inflammation in humans.[97][99][100] These TLR4-stimulating actions of ATIs are limited to gluten-containing cereals.[98] A 2017 find out about in mice demonstrated that ATIs exacerbate preexisting inflammation and may additionally irritate it at extraintestinal websites. This might explain why there is a rise of irritation in other folks with preexisting sicknesses upon ingestion of ATIs-containing grains.[97]
Comparison with other staple foods
The following desk presentations the nutrient content material of wheat and other primary staple meals in a raw shape.[101]
Raw sorts of those staples, on the other hand, aren’t edible and can’t be digested. These must be sprouted, or prepared and cooked as appropriate for human consumption. In sprouted or cooked shape, the relative dietary and anti-nutritional contents of every of these grains is remarkably other from that of uncooked form of these grains reported on this desk.
In cooked form, the diet value for every staple is dependent upon the cooking method (for example: baking, boiling, steaming, frying, and many others.).
Nutrient content of 10 major staple foods per 100 g portion,[102] in order of rank

Nutrient Maize(corn)[A]
Rice, white[B]
Wheat[C]
Potatoes[D]
Cassava[E]
Soybeans, green[F]
Sweet potatoes[G]
Yams[Y]
Sorghum[H]
Plantain[Z]
RDA

Water (g) 10 12 13 79 60 68 77 70 9 65 3,000
Energy (kJ) 1,528 1,528 1,369 322 670 615 360 494 1,419 511 8,368–10,460
Protein (g)
9.4 7.1 12.6 2.0 1.4 13.0 1.6 1.5 11.3 1.3 50
Fat (g)
4.74 0.66 1.54 0.09 0.28 6.8 0.05 0.17 3.3 0.37 44–77
Carbohydrates (g)
74 80 71 17 38 11 20 28 75 32 130
Fiber (g)
7.3 1.3 12.2 2.2 1.8 4.2 3 4.1 6.3 2.3 30
Sugar (g)
0.64 0.12 0.41 0.78 1.7 0 4.18 0.5 0 15 minimal
Minerals [A]
[B]
[C]
[D]
[E]
[F]
[G]
[Y]
[H]
[Z]
RDA

Calcium (mg) 7 28 29 12 16 197 30 17 28 3 1,000
Iron (mg)
2.71 0.8 3.19 0.78 0.27 3.55 0.61 0.54 4.4 0.6 8
Magnesium (mg) 127 25 126 23 21 65 25 21 0 37 400
Phosphorus (mg) 210 115 288 57 27 194 47 55 287 34 700
Potassium (mg) 287 115 363 421 271 620 337 816 350 499 4,700
Sodium (mg) 35 5 2 6 14 15 55 9 6 4 1,500
Zinc (mg)
2.21 1.09 2.65 0.29 0.34 0.99 0.3 0.24 0 0.14 11
Copper (mg) 0.31 0.22 0.43 0.11 0.10 0.13 0.15 0.18 – 0.08 0.9
Manganese (mg) 0.49 1.09 3.99 0.15 0.38 0.55 0.26 0.40 – – 2.3
Selenium (μg) 15.5 15.1 70.7 0.3 0.7 1.5 0.6 0.7 0 1.5 55
Vitamins [A]
[B]
[C]
[D]
[E]
[F]
[G]
[Y]
[H]
[Z]
RDA

Vitamin C (mg)
0 0 0 19.7 20.6 29 2.4 17.1 0 18.4 90
Thiamin (B1) (mg) 0.39 0.07 0.30 0.08 0.09 0.44 0.08 0.11 0.24 0.05 1.2
Riboflavin (B2) (mg) 0.20 0.05 0.12 0.03 0.05 0.18 0.06 0.03 0.14 0.05 1.3
Niacin (B3) (mg) 3.63 1.6 5.46 1.05 0.85 1.65 0.56 0.55 2.93 0.69 16
Pantothenic acid(B5) (mg) 0.42 1.01 0.95 0.30 0.11 0.15 0.80 0.31 – 0.26 5
Vitamin B6 (mg)
0.62 0.16 0.3 0.30 0.09 0.07 0.21 0.29 – 0.30 1.3
Folate Total (B9) (μg) 19 8 38 16 27 165 11 23 0 22 400
Vitamin A (IU)
214 0 9 2 13 180 14,187 138 0 1,127 5,000
Vitamin E, alpha-tocopherol (mg) 0.49 0.11 1.01 0.01 0.19 0 0.26 0.39 0 0.14 15
Vitamin K1 (μg)
0.3 0.1 1.9 1.9 1.9 0 1.8 2.6 0 0.7 120
Beta-carotene(μg) 97 0 5 1 8 0 8,509 83 0 457 10,500
Lutein+zeaxanthin(μg)
1,355 0 220 8 0 0 0 0 0 30 6,000
Fats [A]
[B]
[C]
[D]
[E]
[F]
[G]
[Y]
[H]
[Z]
RDA

Saturated fatty acids (g)
0.67 0.18 0.26 0.03 0.07 0.79 0.02 0.04 0.46 0.14 minimal
Monounsaturated fatty acids (g)
1.25 0.21 0.2 0.00 0.08 1.28 0.00 0.01 0.99 0.03 22–55
Polyunsaturated fatty acids (g)
2.16 0.18 0.63 0.04 0.05 3.20 0.01 0.08 1.37 0.07 13–19
[A]
[B]
[C]
[D]
[E]
[F]
[G]
[Y]
[H]
[Z]
RDA

A raw yellow dent corn
B raw unenriched long-grain white rice
C raw hard red winter wheat
D raw potato with flesh and skin
E raw cassava
F raw green soybeans
G raw sweet potato
H raw sorghum
Y raw yam
Z raw plantains
/* unofficial
Commercial use
Harvested wheat grain that enters business is classified in step with grain properties for the purposes of the commodity markets. Wheat patrons use these to decide which wheat to shop for, as each class has special uses, and manufacturers use them to decide which categories of wheat will likely be most successful to domesticate.

Wheat is widely cultivated as a cash crop as it produces a excellent yield in keeping with unit space, grows well in a temperate climate even with a somewhat short rising season, and yields a versatile, top quality flour this is extensively used in baking. Most breads are made with wheat flour, together with many breads named for the opposite grains they include, as an example, maximum rye and oat breads. The acclaim for meals made from wheat flour creates a large call for for the grain, even in economies with vital food surpluses.
In recent years, low international wheat prices have regularly inspired farmers within the United States to change to more profitable crops. In 1998, the fee at harvest of a 60 kilos (27 kg) bushel[103] used to be $2.68 in keeping with.[104] Some data suppliers, following CBOT apply, quote the wheat market in per ton denomination.[105] A USDA record printed that in 1998, reasonable working costs have been $1.43 in line with bushel and overall costs have been $three.97 in keeping with bushel.[104] In that learn about, farm wheat yields averaged 41.7 bushels in line with acre (2.2435 metric ton/hectare), and standard total wheat manufacturing value used to be $31,900 in line with farm, with overall farm production worth (including different crops) of $173,681 in line with farm, plus $17,402 in government bills. There had been vital profitability differences between low- and high-cost farms, mainly due to crop yield differences, location, and farm size.
Production and intake
In 2016, world wheat manufacturing was 749 million tonnes.[6] Wheat is the primary food staple in North Africa and the Middle East, and is rising in makes use of in Asia. Unlike rice, wheat production is extra popular globally, although 47% of the sector general in 2014 used to be produced through simply 4 countries – China, India, Russia and the United States (desk).[7]
Historical factors
In the 20th century, global wheat output expanded by way of about five-fold, however until about 1955 most of this reflected increases in wheat crop area, with lesser (about 20%) will increase in crop yields per unit area. After 1955 however, there used to be a ten-fold increase within the rate of wheat yield improvement in line with 12 months, and this turned into the most important factor permitting global wheat manufacturing to extend. Thus technological innovation and scientific crop management with artificial nitrogen fertilizer, irrigation and wheat breeding have been the main drivers of wheat output expansion in the second half of the century. There have been some significant decreases in wheat crop area, for example in North America.[106]
Better seed storage and germination talent (and hence a smaller requirement to retain harvested crop for next 12 months’s seed) is any other 20th-century technological innovation. In Medieval England, farmers stored one-quarter in their wheat harvest as seed for the following crop, leaving handiest three-quarters for food and feed consumption. By 1999, the worldwide reasonable seed use of wheat was once about 6% of output.

Several components are currently slowing the velocity of world expansion of wheat manufacturing: inhabitants expansion charges are falling whilst wheat yields proceed to upward push, and the easier financial profitability of different plants similar to soybeans and maize, connected with investment in fashionable genetic technologies, has promoted shifts to different plants.
Farming programs
In 2014, the most productive crop yields for wheat were in Ireland, generating 10 tonnes per hectare.[7] In addition to gaps in farming device generation and knowledge, some massive wheat grain-producing international locations have significant losses after harvest on the farm and as a result of deficient roads, insufficient storage applied sciences, inefficient supply chains and farmers’ inability to carry the produce into retail markets dominated through small shopkeepers. Various research in India, as an example, have concluded that about 10% of general wheat production is misplaced at farm stage, another 10% is misplaced because of poor storage and road networks, and further amounts lost on the retail degree.[107]
In the Punjab region of the Indian subcontinent, as well as North China, irrigation has been a significant contributor to increased grain output. More broadly during the last 40 years, a large increase in fertilizer use along with the larger availability of semi-dwarf types in growing countries, has a great deal higher yields in step with hectare.[8] In creating nations, use of (basically nitrogenous) fertilizer higher 25-fold on this duration. However, farming methods depend on a lot more than fertilizer and breeding to reinforce productiveness. A excellent representation of this is Australian wheat growing in the southern wintry weather cropping zone, the place, despite low rainfall (300 mm), wheat cropping is a success even with rather little use of nitrogenous fertilizer. This is completed by way of ‘rotation cropping’ (traditionally known as the ley system) with leguminous pastures and, within the closing decade, including a canola crop in the rotations has boosted wheat yields by means of an extra 25%.[108] In those low rainfall spaces, better use of to be had soil-water (and better regulate of soil erosion) is accomplished by way of keeping the stubble after harvesting and by minimizing tillage.[109]
Geographical variation
There are really extensive differences in wheat farming, trading, coverage, sector growth, and wheat makes use of in different regions of the world.[6] The biggest exporters of wheat in 2013 were, in order of exported amounts: United States (33.2 million tonnes), Canada (19.eight million tonnes), France (19.6 million tonnes), Australia (18 million tonnes), and the Russian Federation (13.8 million tonnes).[110] The greatest importers of wheat in 2013 had been, in order of imported quantities: Egypt (10.three million tonnes), Brazil (7.3 million tonnes), Indonesia (6.7 million tonnes), Algeria (6.three million tonnes) and Japan (6.2 million tonnes).[110]
In the all of a sudden creating nations of Asia and Africa, westernization of diets associated with increasing prosperity is resulting in enlargement in according to capita demand for wheat at the expense of the opposite food staples.[6][8]
In the previous, there was significant governmental intervention in wheat markets, such as price helps in america and farm payments within the EU. In the EU, these subsidies have encouraged heavy use of fertilizer inputs with ensuing high crop yields. In Australia and Argentina, direct government subsidies are much lower.[citation needed]
Most productive
The reasonable annual global farm yield for wheat in 2014 was 3.three tonnes in keeping with hectare (330 grams according to sq. meter).[7] Ireland wheat farms have been the most productive in 2014, with a nationwide moderate of 10.zero tonnes in step with hectare, adopted via the Netherlands (nine.2), and Germany, New Zealand and the United Kingdom (each with eight.6).[7]
Futures contracts
Wheat futures are traded on the Chicago Board of Trade, Kansas City Board of Trade, and Minneapolis Grain Exchange, and feature delivery dates in March (H), May (okay), July (N), September (U), and December (Z).[111]
Agronomy
Crop development
Wheat most often wishes between 110 and 130 days between sowing and harvest, relying upon climate, seed sort, and soil conditions (iciness wheat lies dormant all the way through a winter freeze). Optimal crop control requires that the farmer have a detailed working out of each stage of development in the growing crops. In particular, spring fertilizers, herbicides, fungicides, and enlargement regulators are typically carried out best at specific stages of plant development. For instance, it is these days really useful that the second software of nitrogen is best possible finished when the ear (no longer visual at this level) is about 1 cm in dimension (Z31 on Zadoks scale). Knowledge of levels may be important to identify classes of higher risk from the climate. For example, pollen formation from the mum mobile, and the stages between anthesis and adulthood are at risk of prime temperatures, and this adverse effect is made worse by means of water rigidity.[112] Farmers additionally take pleasure in figuring out when the ‘flag leaf’ (closing leaf) appears, as this leaf represents about 75% of photosynthesis reactions during the grain filling duration, and so should be preserved from illness or insect attacks to make sure a just right yield.
Several methods exist to identify crop phases, with the Feekes and Zadoks scales being probably the most broadly used. Each scale is a typical gadget which describes successive stages reached through the crop throughout the rural season.
Diseases
There are many wheat illnesses, mainly caused by fungi, bacteria, and viruses.[113] Plant breeding to increase new disease-resistant sorts, and sound crop management practices are essential for fighting illness. Fungicides, used to prevent the numerous crop losses from fungal illness, generally is a important variable value in wheat manufacturing. Estimates of the amount of wheat production lost owing to plant illnesses range between 10–25% in Missouri.[114] a Variety Of organisms infect wheat, of which an important are viruses and fungi.[115]
The major wheat-disease categories are:
Seed-borne illnesses: these come with seed-borne scab, seed-borne Stagonospora (in the past known as Septoria), commonplace bunt (stinking smut), and unfastened smut. These are managed with fungicides.
Leaf- and head- blight diseases: Powdery mildew, leaf rust, Septoria tritici leaf blotch, Stagonospora (Septoria) nodorum leaf and glume blotch, and Fusarium head scab.[116]
Crown and root rot illnesses: Two of the more necessary of those are ‘take-all’ and Cephalosporium stripe. Both of these sicknesses are soil borne.
Stem rust sicknesses: Caused through basidiomycete fungi e.g. Ug99
Viral illnesses: Wheat spindle streak mosaic (yellow mosaic) and barley yellow dwarf are the 2 maximum not unusual viral sicknesses. Control will also be accomplished through the usage of resistant varieties.
Pests
Wheat is used as a meals plant by way of the larvae of some Lepidoptera (butterfly and moth) species including the flame, rustic shoulder-knot, setaceous Hebrew personality and turnip moth. Early within the season, many species of birds, including the long-tailed widowbird, and rodents feed upon wheat crops. These animals could cause important injury to a crop by digging up and eating newly planted seeds or younger crops. They too can harm the crop overdue in the season via eating the grain from the mature spike. Recent post-harvest losses in cereals quantity to billions of dollars in step with year within the United States by myself, and harm to wheat by more than a few borers, beetles and weevils is not any exception.[117] Rodents too can cause major losses right through garage, and in main grain growing areas, box mice numbers can once in a while building up explosively to plague proportions on account of the in a position availability of food.[118] To reduce the quantity of wheat lost to post-harvest pests, Agricultural Research Service scientists have developed an “insect-o-graph,” which will locate insects in wheat that are not visual to the naked eye. The software makes use of electric signals to locate the insects as the wheat is being milled. The new generation is so exact that it may stumble on 5–10 infested seeds out of 300,000 good ones.[119] Tracking insect infestations in stored grain is critical for meals protection in addition to for the selling value of the crop.
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Zero tillage technology for wheat in rice-wheat cropping system

Wheat (Triticum aestivum L.) is the major cereal crop grown in world. World wheat production is 695 million tons (FAO, 2011). In Pakistan it contributes 9.1 % to the value added products in agriculture and 1.7 % to gross domestic production. Currently, the area under wheat is 8.73 million hectares and total production is 25.4 million tons with an average yield of 2.9 metric ton ha-1 (Govt. of Pakistan, 2017-18). Despite a higher yield potential, average grain yield of wheat in Pakistan is well below than in most of the wheat producing countries of the world.

Dr.Muhammad Rafi Qamar

(Department of Agronomy, UOS)

In Pakistan, wheat occupies a central position in regulating agricultural policies and dominates all agronomic crops in the form of total acreage and yield. Wheat is generally grown after rice and cotton in rice-wheat and cotton-wheat cropping system. Rice-wheat cropping system plays an important role not only in Pakistan but also in world food security. In Indian-subcontinent, the area under rice-wheat cropping system is 13.5 million hectares.

 In Pakistan, rice is grown in Kharif season under puddle condition while irrigated spring wheat in Rabi season. The total area is about 2.4 million hectares under rice out of which 50% comprised of fine and long quality speciality rice varieties (Basmati). Fine and long quality rice varieties are late maturing which often delay and / or affect spring wheat planting. However, farmers prefer to grow spring wheat due to its high gross margins. Rice is generally harvested mechanically by combine harvester, which leaves rice stubbles in the field. To overcome the problem of rice stubbles most of the farmers burn the residues because rice stubbles incorporation required several tillage operations, which also delays wheat planting. Irregular tillage operations especially conventional tillage during the seedbed preparation and at late maturing stage of basmati rice delayed the wheat planting.

Conventional management practices including frequent plowing, chemical fertilization, and pesticide application increases crop yields but exerts negative effects on soil productivity and farm economics. Plowing improves soil tilth for crop growth and yield, alleviates soil compaction and nutrient stratification, and suppresses weeds and soil-borne diseases. However, frequent plowing fragments and mixes crop residues, increases soil aeration and temperature, disperses soil structure, accelerates decomposition of crop residues and native soil organic matter (SOM), and causes an increase in CO2 emissions into the atmosphere. Moreover, plowing led to the formation of hardpan at the plow depths, decreases water infiltration with accelerated soil erosion.

            In a rice-wheat cropping system, rice is mostly grown under puddling which leads to the destruction of wet soil aggregates by plowing, sealing of pore spaces, and formation of a subsurface hardpan. This subsoil compaction reduced both the water and nutrient-use efficiencies of subsequent wheat crop owing to decreased root growth. Wheat yield reduction and degradation of soil physical properties depend on the intensity and duration of puddling operations.

Deep tillage of puddle soil reduces the compaction, increases rooting depth, and improves the yield of the following wheat crop. Deep tillage not only alleviates soil compaction but also control weeds through deep burial of weed seeds. In areas where continuous cropping is practiced, deep tillage increases the surface area of soil exposed to sunlight to control certain diseases, insects and weeds. Two passes of subsoiling were more effective than subsoiling with one-pass for not only overcoming the soil compaction but also improving the soil tilth. The soil moisture at 50 to 100 cm depth under deep tillage was more, while the water consumption reduced in the 0 to 50 cm depth. However, deep tillage is costly in terms of fuel and time.

         Wheat yield can be increased by managing resources through conservation management practices. The most important technology is the conservation tillage that has made to overcome soil erosion, maximize vegetative cover on the land, increase soil organic matter, improve carbon, energy and water footprints, and sustain farm economics is zero tillage. Zero-tillage is well known as zero-till, no-till, direct seeding and direct drilling. No-till techniques have been successfully applied on more than 111 million hectare worldwide. Continuous use of reduced or no-till practices substantially improves the net profitability of crop production. The yield of zero-till wheat is equal to or even higher than the yields produced by conventional tillage. However, no-till wheat yields are often affected by weeds pressures and poor crop stand due to soil compaction, anoxic conditions, and immobilization of nitrogen.

No till conversion of plowing is one of the strategies to decrease farming costs, reduce soil erosion, and improve ecosystem services. With NT, surface accumulation of crop residues as mulch influences air, water, and energy exchange between the soil ecosystem and the atmosphere. These processes reduce soil temperature and evaporation during summer months, retain soil moisture longer-especially under dry conditions, and thereby improve crop productivity. Long-term continuous NT has been reported to produce wheat yields equal to or even higher than that of plowed fields.

In rice-wheat cropping systems, rice is harvested by combines, which leave large amount of crop residues in the fields. However, the newly introduced Happy Seeder (HS) cuts and manages the standing stubble and loose straw in front of the furrow openers, retaining it as surface mulch and sows wheat in a single operational pass of the field. Moreover, operational costs for sowing wheat are 50 to 60 % lower with HS than with conventional sowing. The HS technology provides an alternative to burning for managing rice residues and allows direct drilling of wheat in standing and loose residues. However, most constraints in transitional NT or HS are high weed pressure, poor crop stands, soil compaction and stratification of nutrients, and N immobilization. The problem of N immobilization is more acute in alternate year rice-wheat production systems due to high C:N crop residues.

Sustainable crop production depends on the efficient use of N fertilizers. In wheat production, N plays an important role in crop growth and yield. Most of the wheat varieties grown in Pakistan require substantial quantities of N because soil organic matter content is very low. High price and excessive use of N fertilizers as an insurance against crop failures have caused widespread environmental and public health problems that emphasized the need for efficient use of the N fertilizers. There are needs to evaluate the potential effects of surface residues on N transformations and crop development. Tillage operations influence the soil N dynamics because the crop residues which are incorporated in the soil by plowing decompose faster than the residues which remain on the surface under NT and HS. In NT, N release from the crop residues is slow due to partial anaerobesis and/or due to N immobilization. than in tilled systems. However, when applied in excess of crop requirements NT system has a greater loss of N fertilizer by leaching and volatilization than in CT. Current recommendations of N fertilization developed for continuously plowed systems which may not be adequate for optimum production of wheat under NT because extra nitrogen is required for residues decomposition. Therefore, the information on the effects of tillage and N fertilization on wheat production in post-harvest puddle rice fields in presence of stubbles is critical to evaluate the sustainability of the rice-wheat production systems.

China’s hybrid wheat in Pakistan

China’s hybrid wheat, the use of the two-line hybrid technique, has been effectively harvested on a large scale in Pakistan, consistent with a senior professional of a Chinese company which has performed box trials of hybrid wheat types and realized on average 24.4 p.c building up in crop yields.

[woo_product_slider id=”64262″]

Around 150 professionals were sent to Pakistan, the place they visited over 20 towns,” Song Weibo, Vice President of Sinochem Group Agriculture Division, China’s largest agricultural inputs corporate and built-in trendy agricultural services and products operator told the Chinese media.


“The good results from the experiments offer bright prospects for large-scale cultivation of hybrid varieties in Pakistan,” he added.


Song Weibo


“Pakistan’s population has been rapidly increasing, but the country is short on farmland. The project is win-win cooperation,” he added.


Zhao Gancheng

The two-line hybrid technique is steadily used in hybrid rice and wheat. It can building up wheat manufacturing by means of 20 p.c.
The hybrid wheat has been confirmed to outperform standard wheat in relation to yield, water usage and resistance to disease.
Chen Zhaobo, General Manager, CNSGC Hybrid Wheat Seed, a subsidiary of China National Seed Group Co under Sinochem Group Co, which is liable for the hybrid wheat promotion undertaking in Pakistan, said the checks at the hybrid varieties had been carried out in 230 websites, spread over 2,000 hectares of land, most commonly in experimental bases or native farms.

Zhang Shengquan, a professional at the Beijing Academy of Agricultural and Forestry Sciences who oversees the hybrid wheat challenge in Pakistan, said that wheat production in northern Pakistan has higher via 50.1 p.c between 2017 and 2018, mentioning data from

Pakistan’s University of Agriculture Peshawar.

Data from Pakistan-based Guard Agricultural Research and Services Company presentations that all over the same length, wheat production within the country’s center areas has greater through 45 p.c, he added.
Zhang mentioned that drought and top temperatures are the major challenges to planting hybrid wheat in Pakistan. Frequent changes in the insurance policies of the governments also make it difficult to maintain the challenge, he famous.

University of Agriculture Peshawar Professor Muhammad Arif told China Radio International that the arena has been finding out hybrid wheat however nobody has completed China’s stage of luck.


“Pakistan’s population has been rapidly increasing, but the country is short on farmland. The project is win-win cooperation,” he added.


Zhao Gancheng

With the lend a hand from Chinese experts, the method may yield round 6,000 kilograms in step with hectare, twice that of native wheat manufacturing, Arif stated, including it would free up land for different agriculture products.
Zhao Gancheng, director of the Shanghai Institute for the International Studies Center for Asia-Pacific Studies, stated the mission may just lend a hand Pakistan make certain food security and likewise promote China-Pakistan ties.

Wheat | Diseases and Pests, Description, Uses, Propagation

Wheat, is the name given to several plants in the genus Triticum including Triticum aestivumTriticum compactumTriticum spelta and Triticum durum, which are annual or biennial grasses grown primarily for their grain. Wheat species possess an erect smooth stem with linear leaves that grow in two rows on either side of the stem with larger ‘flag’ leaves at the top of the stem. The stem terminates in a spike that is made up on individual spikelets, each possessing 3–9 florets. The wheat fruit develops within the spikelets, maturing to a seed (kernel). Wheat can reach 1.2 m (4 ft) in height and like other cereals, has been developed into different varieties that are adapted to planting at different times of the year. Spring wheat is planted for a late summer harvest, whereas Winter wheat is planted for harvesting in early to mid summer. Overwintering varieties are more commonly grown in regions with mild winters. Wheat may be referred to by variety and these include durum or macaroni wheat (Triticum durum), club wheat (Triticum compactum), spelt wheat (Triticum spelta) and bread wheat (Triticum aestivum). Wheat originated in the Fertile Crescent of the Middle East. 


 

Uses

Wheat is one of the most important food plants in the world. It is used primarily to produce flour for bread. It is used widely in the production of many other baked goods. Wheat grain is also used in the manufacture of alcoholic beverages and alcohol. Wheat straw is used as an animal feed and in the manufacture of carpets, baskets, packing, bedding, and paper. 


 

Propagation


Wheat varieties 
One of the first things to consider before planting is which type of wheat you want to grow. There are several different varieties to choose from depending on the time of year and how you want to utilize your harvest. Wheat is broadly categorized into Winter wheat and Spring wheat. Winter wheat is high yielding and is planted in the Fall and harvested in the Spring or Summer of the following year (depending on location). Spring wheat is not as high yielding but tolerated drier conditions. It is planted in the Spring and harvested in the Fall. Both Spring and Winter wheat is then further categorized as soft wheat, hard wheat, spelt or durum.

General requirements
Wheat can be grown in a wide variety of climates but grows best in cool regions where the temperature is between 10 and 24°C (50–75°F). Wheat will not grow at temperatures above 35°C (95°F). Wheat will grow optimally in a deep, fertile, well draining and well aerated soil at a pH between 5.5 and 7.5.

Planting
Winter wheat varieties should be planted in the Fall approximately 6 to 8 weeks before the first frost date. Spring wheat varieties should be planted as soon as the soil can be worked in the Spring. Commercially grown wheat is usually mechanically drilled using a machine that creates a furrow and drops the seed in before covering it back up. Wheat seeds can be sown by hand broadcasting in smaller areas, or using a hand-cranked seeder. Seeds are usually sown to at depths ranging from 2 to 12 cm (0.8–4.7 in) depending on soil conditions (seed must be sown deeper in drier soil). Once the seeds have been scattered, the soil should be raked lightly to set the seeds at the desired depth.

Harvesting
Wheat is ready to harvest when the stalks and heads have turned from green to yellow and the seed heads are drooping towards the ground. Check the seeds for ripeness before harvest. The should be firm and crunchy and not doughy in texture. Commercially produced wheat is usually harvested using a combine. Smaller plots can be harvested by hand using a scythe or sickle. Small plots can be harvested by snipping off the heads with a pair of scissors. 


 

References

Bockus, W., W., Bowden, R. L., Hunger, R. M., Morrill, W. L., Murray, T. D. & Smiley, R. W. (eds.) (2010). Compendium of wheat diseases. American Phytopathological Society Press. Available at: http://www.apsnet.org/apsstore/shopap…Available for purchase from APS Press.

CABI Crop Protection Compendium. (2008). Triticum aestivum (wheat) datasheet. Available at: http://www.cabi.org/cpc/datasheet/55204. [Accessed 21 April 15]. Paid subscription required.

Duke, J. A. (1983). Triticum aestivum L.. Handbook of Energy crops, unpublished. Available at: http://www.hort.purdue.edu/newcrop/du…. [Accessed 21 April 15]. Free to access.


 
 

Common Pests and Diseases

Diseases

Category : Bacterial

Bacterial leaf streak and black chaff Xanthomonas campestris

Symptoms
Sudden appearance of water-soaked, light brown, elongated lesions on upper leaves; lesions quickly dry out and turn into necrotic streaks on the leaves; black stripes occur on glumes and purple black lesions appear on rachis and peduncle if infection is in the head
Cause
Bacterium
Comments
Disease spread through infected seed and splashing water
Management

Avoid planting seed from infected fields; avoid overhead irrigation; plant less susceptible cultivars

Basal glume rot Pseudomonas syringae

Symptoms
Dull brown to black discoloration of glumes which is more pronounced on the inner side; seeds may be shriveled; if infection is severe, entire glume may be discolored; small water-soaked lesions may form on leaves
Cause
Bacterium
Comments
Disease spreads primarily through infected seed
Management

Avoid planting seed from plants grown in fields where the disease is known to be present

Category : Viral

Barley yellow dwarf Barley yellow dwarf virus (BYDV)

Symptoms
Yellowing leaves, particularly the flag leaves; stunted plants due to shortened internodes; leaves may be red, purpple, orange, green or brown; leaves may be distorted
Cause
Virus
Comments
Transmitted by a few species of aphid; spread of disease is completely dependent on the movement of aphid vectors
Management

Control of aphid population can provide some control of disease but is dependent on knowing which aphids are active in the field; planting to avoid periods of peak aphid activity can provide a measure of control

Category : Fungal

Common bunt (Stinking smut) Tilletia tritici

Symptoms
Slender heads which take longer to turn color than healthy heads; glumes spread apart to reveal spori or “bunt balls” (balls containing fungal spores) which are a similar size to normal kernel but are gray-brown in color; bunt balls break open on harvest and give off a fishy odor
Cause
Fungus
Comments
Disease is most commonly introduced through infected seed although spores are spread by wind
Management

Disease can be controlled by planting resistant wheat varieties, planting disease-free seed and using a seed treatment prior to planting; disease may also be avoided by planting wheat early in the Fall and by shallow seeding

Ergot disease Claviceps purpurea

Symptoms
Main symptoms of ergot is the grains in the head are replaced by dark purple to black sclerotia. This ergot bodies were made up of vegetative strands of fungus. The sclerotic interior is white or tennis white in color. The size of grain kernel and ergot are similar in size. The initial symptom before sclerotia bodies is honey dew symptom occur during flowering stage. The fungus produce yellowish, sugary excretions and can see as droplets on flower parts.
Cause
Fungal
Comments
Ergot is toxic to animals including birds.
Management

Follow crop rotation with non host crops for one year. Deep summer ploughing kills sclerotia bodies present in soil. Keep the field free from grasses and other weeds. Use disease free seeds.

Eyespot Oculimacula spp.

Symptoms
Elliptical lesions that first appear on leaf sheath and gradually spread to stem; lesions are yellow-brown to tan in color and occur length-ways down the stem; lesions can occur individually or groups of lesions can coalesce to form large areas of discoloration; lesions may eventually girdle the stem; a gray, thread-like fungal growth may occur on the stem beneath the lesion; mature stems may have a charred appearance; infected tillers mature early and develop white heads and poorly filled seed; tillers may fall if stems are severely infected
Cause
Fungus
Comments
Primary route of infection is by splashing water; emergence of disease favored by high soil moisture content and a dense crop canopy
Management

Rotation of crop away from cereals for a period of 2-3 years will reduce levels of inoculum in the field; fungicides are commonly applied close to stem elongation to control the disease; plant resistant wheat varieties if available in your area

Fusarium head blight (Scab) Fusarium spp.

Symptoms
One or more spikelets on newly emerged head bleached; pink or orange fungal masses may be visible at the base of infected spikelet; infected spikelets do not produce seed or produce shriveled and/or discolored seed; severe infections can cause the kernels to have a chalky appearance and are frequently lost during harvest
Cause
Fungus
Comments
Fungus survives between seasons on host plant debris – other host include corn and barley; fungus can survive on host debris for several years; warm, moist conditions promote the spread of the disease when present
Management

Control of the disease can be difficult; durum wheat appears to be more susceptible to the disease than common wheat; crop rotation to a non-host is recommended for at least one year; applications of appropriate fungicides if available can help to control the disease in conjunction with the other measures detailed here

Phythium root rot Phythium sp.

Symptoms
The infected plants become chlorotic and/ stunted. Often the symptom is confused with nitrogen deficiency. And the plants may produce shriveled grain. Even a mild infection reduce tillers, plant population and maturity. Since symptom appear through out the field make if difficult to diagnose the disease.
Cause
Fungal
Comments
Fungus live for years in soil and on old root debris.
Management

Use good quality seeds. Provide supplemental phosphorous. Sowing when soil temperature is about 50 F increase germination and establishment. Seed treatment with suitable fungicides.

Powdery mildew Erysiphe graminis

Symptoms
Patches of cottony, white-gray growth on upper surface of leaves which turn gray-brown; chlorotic patches develop on leaves opposite fungal growth; fungal fruiting bodies usually become visible as black dots on the mildew
Cause
Fungus
Comments
Disease emergence favors heavy nitrogen fertilization; high humidity and cool temperatures
Management

Planting resistant wheat varieties is one of the best ways to protect plants from powdery mildew; other control strategies include: application of appropriate foliar fungicides, if available; removal of crop debris from field after harvest to reduce the level of overwintering fungus; removal of volunteer wheat plants which can act as a reservoir for the disease

Rusts Stem rust (Puccinia graminis)
Leaf rust (P. triticina)
Stripe rust (P. striiformis)

Symptoms
Chlorotic flecks or brown necrotic spots on leaves or stems; yellow streaks or patches on foliage; brown necrotic streaks on foliage; raised orange pustules may be present on lesions
Cause
Fungus
Comments
Disease emergence favors cool, wet conditions
Management

The most effective method of controlling rusts is to plant resistant varieties of wheat; other methods of control include: destroying alternate hosts; applications of appropriate protective fungicides; growing wheat varieties that mature early

Tan spot Pyrenophora tritici-repentis

Symptoms
Oval or diamond shaped necrotic lesions with brown centers and yellow halos on leaves
Cause
Fungus
Comments
Disease infection requires a wet period of between 6 and 48 days
Management

Disease can be significantly reduced by rotating crops with non-hosts and tilling crop debris into soil after harvest

Pests

Category : Insects

Aphids (Bird cherry-oat aphid, Russian wheat aphid, Corn leaf aphid, etc.) Rhopalosuphum padi
Diuraphis noxia
Sitobion avenae

Symptoms
Yellow or white streaked leaves; flag leaves may be curled up; plants may be stunted and tillers may lie parallel to the ground; plants may turn a purple color in cold weather; insects are small and soft-bodied and may be yellow, green, black or pink in color depending on species; insects secrete a sugary substance called “honeydew” which promotes the growth of sooty mold on the plants
Cause
Insect
Comments
Fields should be checked for aphid populations periodically after emergence
Management

Sturdy plants can be sprayed with a strong jet of water to knock aphids from leaves; insecticides are generally only required to treat aphids if the infestation is very high – plants generally tolerate low and medium level infestation; insecticidal soaps or oils such as neem or canola oil are usually the best method of control; always check the labels of the products for specific usage guidelines prior to use; in commercial plantations aphid numbers are usually kept in check by predators and natural enemies; beneficial insect populations should be assessed before chemical control is considered; if no beneficial insect populations are present and aphids are damaging then apply appropriate insecticides

Armyworms (Armyworm, Western striped armyworm) Mythimna unipunctata
Spodoptera praefica

Symptoms
Entire leaves consumed; notches eaten in leaves; egg clusters of 50-150 eggs may be present on the leaves; egg clusters are covered in a whitish scale which gives the cluster a cottony or fuzzy appearance; young larvae are pale green to yellow in color while older larvae are generally darker green with a dark and light line running along the side of their body and a pink or yellow underside
Cause
Insect
Comments
Insect can go through 3–5 generations a year
Management

Organic methods of controlling armyworms include biological control by natural enemies which parasitize the larvae and the application of Bacillus thuringiensis; there are chemicals available for commercial control but many that are available for the home garden do not provide adequate control of the larvae

Stinkbugs Euschistus spp.

Symptoms
Damage to head during milk or soft dough stage; stink bugs often carry pathogens in their mouthparts which can cause secondary infections; adult insect is shield-shaped and brown or green in color; may have pink, red or yellow markings; eggs are drum shaped and laid in clusters on the leaves; larvae resemble the adults but are smaller
Cause
Insect
Comments
Adult insects overwinter under leaves, on legumes, blackberries or on certain weeds such as mustard or Russian thistle
Management

Remove weeds around crop which may act as overwintering sites for stink bugs and practice good weed management throughout the year; organically accepted control methods include the use of insecticidal soaps, kaolin clay and preservation of natural enemies

Wireworms Aeolus spp.
Anchastus spp.
Melanotus spp.
Limonius spp

Symptoms
Death of seedlings; reduced stand; girdled stems and white heads; wireworm larvae can be found in soil when dug round the stem; larvae are yellow-brown, thin worms with shiny skin
Cause
Insect
Comments
Larval stage can last between 1 and 5 years depending on species
Management

Chemical control impossible in a standing crop, must be applied at preplanting or as a seed treatment; if wireworms are known to be present in soil fallow field during summer and till frequently to reduce numbers; rotate to non-host crop where possible; avoid planting susceptible crops after a wireworm infestation on cereals without either fallowing of applying appropriate pesticide

Wheat to be cultivated over 8,781.6 thousand hectares

ISLAMABAD : Wheat, a major staple food and cash crop of the country, would be cultivated over 8,781.6 thousand hectares of land across crop producing areas of the country during Rabi season 2018-19 in order to produce about 25.572 million tons of grains for fulfilling the domestic requirements as well as to exports. In this regard, all the provinces including Gilgit Baltistan and Azad Jammu and Kashmir had been assigned a task to ensure the availability of all inputs in order to achieve areas and production targets fixed for the current sowing season, a senior official in the Ministry of National Food Security and Research Tuesday said. Talking to APP, he said, in Punjab, wheat crop to be cultivated over 6,474.9 thousand hectares as against the 6,637.0 thousand hectares fixed for the last year, adding that the crop production targets were fixed at 19.500 million tons during current season as compared targets of 20.00 million tons fixed during the last season.

Meanwhile, the production targets for Sindh was fixed at 3.800 million tons by cultivating the crop over an 1,150 thousand hectares and in Khyber Pakhtunkhwa wheat crop would be cultivated over 756.7 thousand hectares to produce 1.362 million tons as compared the area of 757.6 thousand hectares of same period of last year, he added.

He further informed that wheat crop would be cultivated over 400 thousand hectares as against the same area of last year to produce about 900,000 metric tons of the commodity during Rabi season 2018-19.

He said country had harvested bumper wheat crop during last season, despite that the sowing had witnessed 1.8 percent decrease in the area under wheat production, adding that wheat production was increased by 3.67 percent as compared the same period of  last year.

It is worth mentioning here that wheat exports from the country had registered tremendous increase as during last three months of current financial year  about 437,832 metric tons of wheat valuing US$ 92.781 million were exported as compared the exports of 173 metric tons costing US$ 1.555 million of same period of last year.

Wheat (Triticum aestivum L.) Allelopathy and its Implications for Weed Management and Rhizosphere Ecology

Studies were carried out to evaluate the allelopathic potential of four hexaploid wheat (Triticum aestivum L.) cultivars (Millat-2011, AARI-2011, Lasani-2008 and Faisalabad-2008) at different growth stages tillering (Z30), anthesis (Z60) and maturity (Z90). The objectives were to ascertain wheat allelopathic potential to suppress emergence and establishment of important grassy and broad-leaved weed species and characterize soil microbial dynamics and enzyme activities under wheat allelopathy. The overall goal was to characterize the variability in wheat allelopathic potential with respect to plant age, cultivar-specific differences, and relevance to soil functional diversity. One field experiment and four wire-house experiments were carried out at the Student Research Area, University of Agriculture, Faisalabad. Field Experiments: The soil at the experimental site belongs to the Lyallpur Soil Series (USDA classification-Aridisol-fine-silty, mixed, hyperthermic Ustalfic, Haplargid; FAO classification -Haplic Yermosols). Wheat cultivars were sown in 4 m × 10 m field plots, and were maintained either weedy or weed free. Fallow plots (without wheat) were used as a control. Trials were laid out in randomized complete block design with four replications. Data were collected on crop growth, weed density and dry biomass, soil chemical and biological properties. Herbage of wheat cultivars was collected at tillering, anthesis and maturity for biochemical analysis. Weed densities were significantly lower in plots sown with wheat than in control plots. Floristic composition of weeds varied significantly among wheat cultivars and between years. A total of seven broad leaf (swine cress, lambsquarters, blue pimpernel, field bind weed, sweet clover, fathen, fumitory and broadleaf dock), three grassy weeds (canarygrass, and bermudagrass) and one sedge (purple nutsedge) belonging to seven distinct families (Poaceae, Chenopodiaceae, Brassicaceae, Primulaceae, Cyperaceae, Fabaceae and Convolvulaceae) were identified. Summed dominance ratios of the weeds were in the order: swine cress > lambsquarters > blue pimpernel > canarygrass > field bind weed > purple nutsedge > sweet clover during 2011-12, and swine cress > blue pimpernel > lambsquarters > canarygrass > field bind weed > purple nutsedge > sweet clover during 2012-13. Summed dominance ratios changed during the growing season due mainly to variation in emergence timing of different weeds; sweet clover emerged at 60 days after sowing (DAS) and broadleaf dock at 75 DAS during 2011-12. Sweet clover and broadleaf dock were identified at 45 and 60 DAS during 2012-13, although during 2011-12, these weeds were absent at these times. Total weed dry biomass at 45 DAS ranged from 0.81-1.39 g m-2 during 2011-12 and 0.45-0.83 g m-2 during 2012-13 in plots sown with wheat compared to 13.02 g m-2 and 2.78 g m-2 in fallow plots, for respective years. At 105 DAS, total weed dry biomass was significantly lower (4.96-14.13 g m-2 and 5.02-6.11 g m-2) in wheat-sown plots than fallow plots (109.38 and 183.24 g m-2) during 2011-12 and 2012-13, respectively. HPLC profile of allelochemicals revealed that wheat herbage contained eight compounds: gallic acid, p-hydroxybenzoic acid, syringic acid, ferulic acid, vanillic acid, protocatechuic acid, p-coumaric acid and benzoic acid. Concentrations of these allelochemicals varied among wheat cultivars and with stage of growth. Concentration of total allelochemicals in 2 wheat cultivars was in order: AARI-2011 > Lasani-2008 > Millat-2008 > Faisalabad-2008, and for growth stages the order was maturity > anthesis > tillering. Higher total phenolic content was recorded in field soil collected at maturity stage of wheat than at tillering and anthesis stages. During the two growing seasons maximum phenolic content (51.73-60.23 mg g-1 soil) were recorded for soil from AARI-2011 plots as compared to fallow (control; 18.09-14.59 mg g-1 soil) respectively. HPLC analysis of wheat-amended rhizosphere soil showed that concentrations of root-exuded, phytotoxic compounds varied with cultivars and the stage of growth of wheat. The overall concentration of allelopathic compounds in rhizosphere soil collected at tillering stage was in order: ferulic acid > benzoic acid > p-hydroxamic acid > gallic acid, at anthesis stage p-hydroxamic acid > ferulic acid > vanillic acid > benzoic acid > p-coumaric acid > syringic acid > protocatechuic acid. However, at maturity the order was p-hydroxamic acid > ferulic acid > benzoic acid > protocatechuic acid > syringic acid > vanillic acid > p-coumaric acid. Maximum invertase, dehydrogenase, cellulase, and phosphatase activities in rhizosphere soil of all wheat cultivars were recorded at anthesis and maturity as compared to tillering. These activities manifested a temporal increase as soil microbial activity, microbial-carbon and -nitrogen increased at the later growth stages (anthesis and maturity). Pot Experiments: Dried herbage was incorporated at 8 g kg-1 soil in plastic pots (10 cm × 26 cm). Control treatment was comprised of soil without herbage. At 7 days after incorporation of herbage, 20 seeds each of canarygrass (Phalaris minor Retz.) and common lambsquarters (Chenopodium album L.) were sown in each pot including control pots (without herbage). Separate experiments were carried out for both the test species. A similar but separate (blank) experiment was set wherein no weed species was grown, to explore the decomposition pattern of wheat herbage and its impact on activities of soil microorganisms and extracellular enzymes. The release of phytotoxic compounds was quantified over a 6-week incubation period. In another set of experiment, leachates were collected from wheat-sown and control pots (soil without wheat). These leachates were used in another set of pot experiment wherein canarygrass and lambsquarters were sown. A separate pot experiment was conducted to appraise the interference potential of wheat cultivars on emergence and seedling growth of test weed species (canarygrass and lambsquarters). For this purpose, wheat cultivars and test species were sown in 1:1 ratio in plastic pots. Control pots contained only one seed type (either of wheat or weed seed). Allelopathic potential against the weed species was evaluated on the basis of seed germination and seedling growth; and biochemical and antioxidant enzyme analyses were carried out to understand the basis for possible allelopathic interference. To have an insight into rhizosphere ecology analyses of microbial abundance (population of bacteria and fungi, soil-microbial-biomass-carbon and -nitrogen) and analysis of extracellular enzymes (cellulase, urease, invertase, dehydrogenase, phosphatase, and polyphenol oxidase) were performed. All pot experiments were conducted using completely randomized designs with four replications. Experiment-I A: Incorporation of herbage collected at anthesis and maturity stages of wheat cultivars AARI-2011 and Lasani-2008 prolonged mean emergence time of canarygrass to greater than the control. Final emergence percentage dropped by 13-31% in response to soil incorporation of herbage collected at different growth stages. Maximum suppression of shoot (33-51% and 28-53%) and root (34-52% and 28-54%) lengths and seedling dry biomass (66- 3 88% and 58-86%) of canarygrass over control was also observed with the aforementioned treatment combinations. Total chlorophyll content declined where herbage collected at anthesis and maturity stages of all wheat cultivars was incorporated into soil, but phenolic content was higher than with the control where herbage collected at tillering was applied. Activities of enzyme antioxidants also varied among wheat cultivars, and declined with the incorporation of herbage collected at anthesis and maturity but were enhanced by tillering stage herbage compared with the control. Wheat herbage induced lipid peroxidation in canarygrass seedling. Higher malondialdehyde (MDA) content (1.28 and
1.14 nmol g-1 FW) was observed by the incorporation of herbage of wheat cultivars AARI-2011 and Lasani-2008, respectively. Anthesis- and maturity-stage herbage of AARI-2011 and Lasani-2008 was more phytotoxic than that of Millat-2011 and Faisalabad-2008. Moreover, herbage of all wheat cultivars collected at tillering stage had a stimulatory effect on emergence, seedling growth and biochemical attributes of canarygrass. Experiment-I B: Mean emergence time (MET) of lambsquarters was prolonged over control with herbage of all wheat cultivars collected at anthesis and maturity stages. Final emergence percentage dropped by 3-17% in response to herbage collected at different growth stages. Maximum suppression of shoot (45 and 78%) and root (60 and 90%) lengths, and seedling dry biomass (65 and 96%) of lambsquarters over control was recorded in response to amendment with herbage collected at anthesis and maturity stages of wheat. Total chlorophyll content declined to lower than the control in response to incorporation of herbage from all wheat cultivars collected at anthesis and maturity stages. Phenolic content, on the other hand, increased. Activities of enzyme antioxidants extracted from lambsquarters varied with wheat cultivar and declined with the incorporation of herbage collected at tillering, anthesis and maturity stages. Wheat herbage induced lipid peroxidation in lambsquarters seedlings, and higher MDA content (0.56 and 0.77 nmol g-1 FW) was observed with the incorporation of herbage collected at anthesis and maturity stages, respectively. Herbage of Millat-2011, AARI-2011 and Lasani-2008 collected at anthesis and maturity stages was more phytotoxic than that of Faisalabad-2008 collected at the same stages. Moreover, herbage of all wheat cultivars collected at tillering stage only mildly inhibited emergence, seedling growth and biochemical attributes of lambsquarters. Experiment-II: Wheat herbage amendment increased soil pH, phenolic content, organic-carbon and -nitrogen content compared to nonamended soil. Total carbon, total nitrogen, total soluble phenolic content, and saturated and unsaturated fatty acids were significantly different in soil amended with wheat herbage collected different growth stages. Maximum total carbon and nitrogen were observed for herbage collected at anthesis and maturity stages compared to herbage collected at tillering. Both of the organic-carbon and -matter significantly increased with progression in incubation time where wheat herbage was incorporated into soil; whereas these soil components declined in nonamended soil. Analysis of herbage-amended-soil during different incubation periods showed that microbial population, and activities of extracellular enzymes (urease, invertase, dehydrogenase, and phosphatase) increase during the six-week incubation period. All these activities were higher in the soil amended with herbage of Millat-2011 and AARI-2011 collected at anthesis and maturity stages than with those of Lasani-2008 and Faisalabad-2008 collected at same growth stages. The concentrations of phytotoxic compounds from decomposing wheat 4 herbage also differed with cultivar, stage of growth at which herbage was collected, and the incubation period. HPLC analysis of soil extracts from soil amended with wheat herbage showed that they contained eight phytotoxic compounds gallic acid, p-hydroxybenzoic acid, syringic acid, ferulic acid, p-coumaric acid, vanillic acid, protocatechuic acid and benzoic acid the concentrations of which were dependent on growth stage and the duration of herbage incubation in the soil. Experiment-III A & B: Application of leachates from herbage-amended soil affected emergence dynamics of both canarygrass and lambsquarters seedlings in a cultivar-dependent manner compared to the control. Leachate from AARI-2011-amended soil significantly reduced the final emergence (14 and 23%) and seedling dry biomass (36 and 64%) of both canarygrass and lambsquarters, respectively, compared to the control. Application of leachates from soil amended with AARI-2011 and Lasani-2008 herbage significantly reduced the protein content of canarygrass (48-53%) and lambsquarters (90-92%). Catalase and peroxidase activities of canarygrass (272% and 45%) and lambsquarters (83 and 82%) also declined under the influence of leachates from AARI-2011-amended soil compared to the control. Reduced superoxide dismutase activities were recorded with the application of leachates from soils amended with all wheat cultivars compared to control for both weed species. Application of root leachates significantly influenced the populations of soil bacteria and fungi compared to control. Maximum increases in microbial populations and soil enzymatic activities were recorded under the influence of root leachates from AARI-2011-amended soil in both canarygrass and lambsquarters sown pots. Experiment-IVA & B: None of the wheat cultivars showed reduction in emergence and seedling growth in response to interference by canarygrass and lambsquarters when grown in a 1:1 ratio. Emergence index and final emergence of canarygrass were inhibited by 25 and 21%, respectively, when grown with wheat cultivars. Similar results were recorded for lambsquarters. Reduction in shoot length (39%) and seedling dry biomass (79%) of canarygrass occurred due to interference of wheat cultivars compared with the control. Shoot and root lengths of lambsquarters were significantly reduced (43% and 48%, respectively) compared to the control. Interference of wheat cultivars reduced the seedling dry biomass of lambsquarters by 49%. The highest reduction was recorded with AARI-2011. It can be concluded from the results of the present investigations that wheat demonstrated allelopathic potential that varied with cultivar as well as growth stage. Wheat cultivars AARI-2011, Millat-2011 and Lasani-2008 were more allelopathic at anthesis and maturity stages than at tillering stage. Wheat cultivars and the stage of crop growth resulted in modifications in rhizosphere microbial communities that may be due to the release of allelochemicals during the herbage decomposition process. Phenolic content of herbage increased with advancement in stage of wheat growth, which was also evident in soil amended with such herbage. The information generated provides evidence in support of soil incorporation of herbage of specific wheat cultivars to manage weeds of economic significance in wheat-based cropping systems and for increasing soil quality.

This is abstract of PhD thesis of FARHENA for complete thesis visit http://prr.hec.gov.pk/jspui/handle/123456789/7061

Top 10 pests of Wheat

1.       Termites

Biology

Egg: Dull, kidney shaped and hatches in 30-90 days.

Nymph: Moult 8-9 times and are full grown in 6-12 months.

Adult: Creamy coloured tiny insects resembling ants with dark coloured head.

Damage symptoms

TermitesTermites damage the crop soon after sowing and sometimes near maturity. They feed on roots, stem of growing plants, even dead tissues of plant feeding on cellulose. The damaged plants dry up completely and are easily pulled out. The plants damaged at later stages give rise to white ears. Infestation is heavy under unirrigated conditions and in the fields where un-decomposed farm yard manure is applied before sowing.

2.       American pod borer

Biology

It is a polyphagous, infesting gram, lablab, safflower, chillies, groundnut, tobacco, cotton etc.

Egg: The spherical, yellowish eggs are laid singly on tender parts and buds of plants. The egg period lasts for 2-4 days.

Larva: Caterpillars are of varying colour, initially brown and later turn greenish with darker broken lines along the side of the body.

The larval period lasts for 18-25 days. Body covered with radiating hairs. When full grown, they measure 3.7 to 5 cm in length. The full grown caterpillar pupates in the soil in an earthen cell and emerges in 16-21 days.

Pupa: Pupation takes place inside the soil, pupal stage lasts 7-15 days.

Adult: Moth is stout, medium sized with brownish/greyish forewings with a dark cross band near outer margin and dark spots near costal margins, with a wing expanse of 3.7cm.

Damage symptoms

Young larva feeds on the leaves for some time and then attacks earheads. Internal tissues are eaten severely and completely hollowed out. While feeding the caterpillar thrust its head inside leaving the rest of the body outside.

Fed leaves awns and earheads.

Natural enemies of american pod borer

Parasitoids: Tricogramma chilonis, Tetrastichus spp., Chelonus spp., Telenomus spp. (egg) Bracon spp., Ichneumon promissorius, Netelia product, Chrysoperla zatrowii sillemi, Carcelia spp., Ovomermis albicans, a nematode, Chaetopthalmus, Campoletis chloridae (larval), Lissopimpla excels, Ichneumon promissorius (pupal)

Predators: Coccinellids, King crow, Braconid wasp, green lacewing, dragon fly, spider, robber fly, reduviid, praying mantis, red ants.

3.       Aphids

Biology

Eggs: Eggs are dirty white in colour and laid along the veins of leaves.

Nymphs: There are four nymphal stages (instars). The general appearance of each stage is similar except for increase in size during subsequent instars. The first, second, third and fourth nymphal stages last 1-2, 2, 2, and 3 days respectfully. The nymphs and the females look alike, except that the latter are larger. It breeds at a fast rate during cold weather and reaches the height of its population in February-March when the ears are ripening.

Adults: Aphids are small, soft-bodied, pearl-shaped insects that have a pair of cornicles (wax-secreting tubes) projecting out from the fifth or sixth abdominal segment. Aphids are green colour. Both apterous (wingless) and alatae (winged) forms pass through 4-5 nymphal instars in their development and the nymphal period ranges from 5-7 days. Both the forms mate within a day or two after the final moult and start reproducing young ones. The apterous forms produce significantly more number of young ones than alatae but their life-period is shorter than that of alatae.

In the field generally viviparous apterous forms are observed in large number.

Damage symptoms

Like other aphids, the nymphs and adults suck the sap from plants, particularly from their ears. They appear on young leaves or ears in large numbers during the cold and cloudy weather.

The damage is particularly severe in years of cloudy weather. A heavily manured, well-irrigated and succulent crop will harbour the pest for a longer period and suffer greater damage.

Natural enemies of aphid

Parasiotids: Aphidius spp., Aphelinus spp. etc.

Predators: Syrphid fly, lacewing, minute pirate bug damsel bug and ladybird beetle, praying mantis, predatory thrips, rove beetle etc.

4.       Brown mite

Biology

Eggs: Hyaline, globular laid in mass. Eggs are generally laid beneath clods and are either active i.e. red in colour and not visible to the naked eye or dormant i.e. white eggs.

Clearly visible on the underside of clods

Nymphs: Yellowish in colour

Adults: The mites are very small measuring about 0.5 mm in length, metallic brown to black with pale yellow legs and their forelegs are distinctively longer than the other three pair of legs.

Damage symptoms

They feed on leaves by sucking sap by inserting two needle like stylets into the leaf there by withdrawing nutrients from the plants.

Affected leaves become whitish and under severe conditions become reddish brown and bronzy Leaves wither and dry

Natural enemies of mite

Predators: Oligota spp., Anthrocnodax occidentalis, Feltiella minuta etc., Green lacewings (Mallada basalis and Chrysoperla zatrowii sillemi), lady bugs.

Predatory mite: Amblyseius alstoniae, Phytoseiulus persimilis. Predatory coccinellid beetle – Stethorus punctillum.

5.       Army worm/cut wormBiology

Eggs: Eggs are laid in cluster, consisting of approximately 500 eggs

Larvae: The younge caterpillars hatch from the eggs in 4-5 days. After hatching the caterpillars starts feeding on the leaves of the seedlings. The caterpillars are fully grown in about 15 days and measures 3-5 cm in length. Larvae usually have 6 instars (very seldom 7 instars), reaching 40 mm in length at older age. Larva with 2 wide black-brown and one intermediate light dorsal stripe, with black-brown lateral stripe along spiracle line; spiracles brown with black rim.

Pupae: Larvae pupate in soil at depths to 2 cm, under lumps of ground or under tussocks. Pupal phase lasts 13-21 days. Pupae are yellowish-brown, shiny. Body length is about 15-20 mm. It has a cremaster on last segment bearing 2 bent and crossed spines and 4 thin hooked setae.

Adults: Adult is brownish white in colour. Forewings are grayish-yellow, with dark-gray or reddish-yellow tint. Round and reniform spots are light or yellowish with indistinct edges; reniform spot with white point at lower margin. External wing margin blackened obliquely from top backward, with dark stroke and with a row of dark points. Hind wings are gray, with dark external margin. Antennae are thread-like.

Damage symptoms

The primary symptom is defoliation of the plant. Larvae feed on leaves, chewing from the edges to the midrib, or on the heads of cereal plants.

Heavy infestations can be very destructive; larvae may climb the plant and sever the neck just below the head. Some species may be found feeding at the soil surface, others underground feeding on roots, and still others feeding inside the stem.

The armyworm feeds during dawn and dusk period as it is shy of sun light.

Parasitoids and Predators: Same as Helicoverpa armigera

6.       Shoot fly

Biology

Eggs: The eggs hatch in 1 – 3 days and the maggots which are yellow in colour migrate to the dorsal surface of the leaf, enter the space between the leaf sheath and the axis and make a clean cut at the base of the leaf. The growing point of the plant dies and decays on which the maggots feed.

Larvae: The larval period lasts for 6 – 10 days.

Pupae: Pupation takes place inside the stem itself and the adults emerge in about a week.

Adults: The adult is a small dark fly. It deposits whitish eggs singly on the central surface of the leaves. Each female fly is capable of laying 30 eggs during its life time. Life cycle occupies 17 – 20 days.

Damage symptoms

The maggots bore into the shoot of young plants, a week after germination to about one month and as a result the central shoot dries up resulting in „dead hearts‟. If it is a little later the mother plant may produce side tillers. But the tillers also may be attacked. The infestation often goes as high as 60%.

7.       Wheat thrips

Biology

Eggs: Embryonic development lasts 9-10 days.

Nymphs: There are 2 instars; nymphal development lasts 23-27 days. The young nymph feeds on the lemmae and then penetrates the flower which may become sterile due to the nymph’s feeding damage. When the grain has reached the milky-ripe stage, the nymph moves into the furrow of the grain and attacks the pericarp. Once it has completed its development, the nymph vacates the lemmae and falls to the ground. ‘Pupation’: there are 3 stages, 1 ‘pre-pupal’ and 2 ‘pupal’, lasting only a few days.

Adults: Adults are very small, brown or black insects with a tapering, segmented abdomen, elongated and fast moving measuring 2 mm in length with four narrow fringed wings and live for about 10-12days.

Damage symptoms

They are usually infecting the sheath of the flag leaf, feeding on the stem. However, leaves, stems, and heads may be attacked. Adults and nymphs both can cause damage and, if present in large numbers, may cause the tissue on which they are feeding to take on a silver coloration.

Natural enemies of wheat thrips

Parasitoids: Thripobius semiluteus

Predators: Franklino thrips, predatory mite, hoverfly.

8.       Pink stem borer

Biology

Eggs: Round pearl like yellowish eggs ranging 80-300 are layed in 2-3 longitudinal rows usually within the sheaths of bottom leaves of young plant of two to three weeks old. As the time for hatching approaches, eggs become brown or shy grey.

Larvae: Newly hatched larvae remain in group behind the leaf sheath and begin chewing on the stem and epidermal layer of the sheath. Full grown larvae are stout smooth about 25 to 30 mm in length purplish pink on the dorsal side and white on ventral side.

Pupae: Pupa is dark brown in colour.

Adults: The adult moth is straw-coloured with white wings. Life cycle is completed in 6-7 weeks with 4-5 generations in a year.

Damage symptoms

Severe damage causes the stem to break. Severely infected plants due to stunting may appear to have some times the cob and tassel at one place. Whorl feeding of larvae results in rows of oblong holes in unfolding leaves unlike round shot holes produced by Chilo partellus.

Later they bore in to central shoot resulting in the drying up of the growing point and formation of “dead heart” in young plant as a result of larval feeding sometimes the bottom internodes show circular ring like cuts. At ear head stage “white ears” are produced.

Natural enemies of pink borer

Parasitoids: Apanteles,Tetrastichus, Telenomus, Trichogramma japonicum ,T chilonis, Bracon etc.

Predators: Spiders, drynids, water bugs, mirid bugs, damsel flies, dragonflies, meadow grasshoppers, staphylinid beetles, carabids, coccinellids etc.

9.       Ghujhia weevil

Biology

Eggs: Insect mate frequently and lay 6-76 eggs in 5-11 installments in the soil under clods or in crevices in the ground. The egg period is 6-7 weeks.

Larvae: Young grubs enter the soil. Grub period is 10-18 days.

Pupae: Larvae pupate in earthen chambers at a depth of 15-60 cm. The pupal stage lasts 7-9 weeks.

Adults: Weevils are earthen grey and measure about 6.8 mm in length and 2.4 mm in width. Their fore wings are oblong and hind wings are more or less triangular, but they cannot fly. The pest is active from June to December and undergoes larval or pupal diapause during rest of the year in the soil.

Damage symptoms

Only adults feed on leaves and tender shoots of the host plants. They cut the germinating seedlings at the ground level. Often the crop is resown. The damage is particularly serious during October-November when the rabi crops are germinating.

10.   Root-knot nematode

Biology

Wheat showing symptoms of root knot nematode (Meloidogyne spp.). Infestations of root knot nematodes are characterized by the formation of small knots or galls near the tips of the roots. Above ground, infested plants are stunted and chlorotic. Excessive branching of affected roots sometimes occurs.

Most species of plant parasitic nematodes have a relatively simple life cycle consisting of the egg, four larval stages and the adult male and female.

Development of the first stage larvae occurs within the egg where the first molt occurs.

Second stage larvae hatch from eggs to find and infect plant roots or in some cases foliar tissues.

Under suitable environmental conditions, the eggs hatch and new larvae emerge to complete the life cycle within 4 to 8 weeks depending on temperature.

Nematode development is generally most rapid within an optimal soil temperature range of 70 to 80°F.

Damage symptoms

Infected plants in patches in the field

Formation of galls on host root system is the primary symptom

Roots branch profusely starting from the gall tissue causing a „beard root‟ symptom

Infected roots become knobby and knotty

In severely infected plants the root system is reduced and the rootlets are almost completely absent. The roots are seriously hampered in their function of uptake and transport of water and nutrients

Plants wilt during the hot part of day, especially under dry conditions and are often stunted

Nematode infection predisposes plants to fungal and bacterial root pathogens

Survival and spread

Primary: Egg masses in infected plant debris and soil or collateral and other hosts like Solonaceous, Malvaceous and Leguminaceous plants act as sources of inoculums.

Secondary: Autonomous second stage juveniles that may also be water dispersed.

Favourable conditions:  Loamy light soils.

Wheat: some semblance of clarity obtaining in mark

July 11, 2013 

Wheat

As the provincial food departments enter the last leg of their procurement drives, things are finally gaining some semblance of clarity in the market.

In a telephonic conversation earlier this week, sources within Punjab Food Department brought BR Research up to date with the government’s wheat buying activities, which have been right on track as planned.

From the onset, this year’s harvest has been mired in innumerable controversies.

First, market participants vehemently opposed the late start of the procurement process (food agencies meanwhile remained adamant that the moisture level of the crop merited the late purchases).
And as things progressed, prices of the staple commodity began climbing as a fear took hold in the market vis-à-vis the size of the crop. As of this week, the banter between provincial food agencies and traders remains tense as officials blame the traders for hoarding in a bid to create panic, while market players point fingers at the food departments for extorting bribes from growers in exchange for gunny bags.
Although, the size of the crop is indeed smaller than expected, there are ample indications that the market will come down. As it is, market sources reveal that the time is right for all growers who have been hoarding to sell the crop before the government leaves the market- which will be in another 10 to 15 days.
In the meantime, wheat sowing in Russia’s Siberia region has reportedly been delayed as the area suffers from a prolonged dry spell which has delayed grain sowing activities in the biggest spring wheat producing area. USDA reports spring wheat planting standing at 43 percent at the close of this week, well behind the 92 percent sowing completed at the same time last year.
Consequently, European wheat futures gained during the week. The November milling wheat on the benchmark Paris futures market was up by 0.49 percent at $270/ton on Thursday. Wheat
In the American futures market, wheat exhibited a similarly healthy stance this week, strengthening off the back of robust US export data. After having rallied for two days straight, Chicago Board of Trade wheat futures rose 2.1 percent on Thursday, hitting the highest price in more than a week. Kansas City Board of Trade hard red winter wheat futures and MGEX spring wheat also closed higher.

COTTON
Cotton trading this week remained slow once more as mills continued to buy hesitantly amid lacklustre exports and a quieter local spinning sector. Sources report that an unsold stock of 20,000 odd bales still lies with ginners, unable to find buyers who await the arrival of the new crop- which is expected to hit markets in Sindh as early as mid-July.
Moreover, there is little indication that trading will pick up in the coming weeks. According to latest export numbers published by PBS, textile export figures for April show the full effect of the debilitating energy shortfalls in Punjab.

Having slipped 3.9 percent month-on-month, exports for cotton yarn and textile made ups including garments have shed 9.6 and 10.42 percent respectively as the local industry struggles to fulfil export orders.
On the international front, the week saw the supply situation finally easing in America and Chinese buying has also been slower as of late, prompting slippages in futures.

The most-active July cotton contract on ICE Futures US subsequently fell 1.64 cents, or two percent, to settle at 81.78 cents/lb. Earlier in the week, the contract had dropped as low as 81.52 cents/lb after breaching a key technical support.

RICE
The week saw prices strengthen in the rice market, with Pakistani sellers raising their price quotations by as much as $5 for a number of varieties including the five and six percent brokens. Meanwhile, data released by PBS reveals China as the leading destination for Pakistani rice as of April- with over 23 percent of the country’s non-basmati exports destined for Beijing during the Jul-Apr period.
However, REAP reports that dispatches sent out to traditional markets of Basmati rice such as the UK and the Middle East were as much as 50 percent below last year’s export numbers during the same period. This has largely been due to the much more attractive Indian Basmati rice, which at a cheaper price has not only captured a large chunk of the Iranian business, but has also managed to elbow Pakistan out of the traditional European markets effectively.
One important piece of news to hit media outlets this week was that Chinese authorities had found traces of Cadmium in rice originating from the Hunan province. Sales have subsequently taken a major hit and many are predicting that this might help the Thai rice gain some much coveted lost footing in the market. Quotes for Thai rice however continue to remain unchanged for the time being.
SUGAR
The week saw a Presidential order levy a 16 percent GST on sugar before the budget announcement, in a bid to collect an estimated Rs10 billion to counter some of the loss of revenue to the exchequer. The news has predictably been met with much hand wringing by the PSMA associates who agree that the sector’s profitability will on the whole be greatly jeopardised.
But much worse off will be the much suffering growers who already bear the brunt of outstanding payments at the hands of the mills. Already weighed in by a supply glut, and without much leg room to pass off the additional costs onto the customers, industry experts agree that the local sugar industry might be in for hard times as a consequence of the imposition.
On the global sugar scene, things remain once more in limbo. Mounting inventories, bountiful harvests and no foreseeable supply disruptions on the horizon have weighed in on prices and raw sugar futures in New York fell to a near 3-year low as expectations for a record sugarcane harvest in Brazil mounted for another week.
The most-active July contract hence settled at 16.81 cents/lb, down eight points after futures reached, but failed to break through the psychological level of 17 cents/lb on Thursday. The contract also managed to touch 16.8 cents during the session, its lowest since July 2010.

Source: Business Recorder

News Collected by agrinfobank.com Team

Pre and post harvest losses in wheat

QAMAR-UL-HASSAN SIDDIQUI & MUHAMMAD SARWAR

Nuclear Institute of Agriculture (NIA) Tandojam.

Basically, Pakistan is an agricultural country and therefore, all roads to the nation’s socio-economic progress and prosperity lead through a modernizing agricultural and a concurrent effort at industrializing particularly based on the home grown raw materials. Being the dominant sector of the economy, agriculture contributes 25% to gross domestic product (GDP), employees 44% of country’s working force and contributes substantially to export earnings. Major crops such as, wheat, rice, cotton and sugarcane account for nearly 89% of value added in major crops. The value added in major crops accounts for 41% of value added in overall agriculture. Thus, these four major crops, on an average, contribute 36.5% to the value added in agriculture. While, the minor crops such as pulses, potato, vegetables, fruits etc. account for 10% of value added.

Wheat pre and postharvest lossesOur major objectives are to increase the production, either by increase in areas or productivity. Acreage increase has limitations like scarcity of water and precariously established balance in land allocation between equally important cash crops. Any disturbance in this balance may cause another crisis, more or less of equal severity. Hence, productivity enhancement along with pre and post harvest losses management are the only alternative and is viable meaningfully, because of the existing differential between the national average and the potential. The low national average is due to the fact, that three-fourth of the farmers do not use proper technological management in adequate quantity and proper combination of local available resources.

Wheat (Triticum aestivum L.) belongs to the Gramineae family. In Pakistan wheat is the most important food crop. The largest cropped area is devoted to wheat, which is about 8.5 million hectares and the quantity produced is more than that of 2.9% to GDP. The unprecedented drought conditions in the country have severely affected the wheat crop. Firstly, the area under the crop declined by 3.8% from 8463 thousand hectares to 8137 thousand hectares in the year 2000-2001. Secondly, according to the preliminary estimates, the size of wheat crop is 12.1% lower than the last year, declining from 21.079 to 18.535 million tons. The area, production and yield are 8306.6 thousand hectares, 18237.6 thousand tons, and 2196.0 thousand kg per hectare, respectively. On the other hand, its procurements, releases and stocks are 8582.0, 5537.0 and 3526.0 thousand tons, respectively.

Losses in wheat

Wheat is adapted to temperate regions, receiving annual rainfall of about 500-1200 mm. Higher precipitation causes lodging and diseases and interferes with field operations of planting and harvesting, so the yield is reduced. In rain fed areas, if rainfall occurs early, wheat can be planted in the last fortnight of October. Late planting of wheat can be done up to the middle of December, after which further delay in sowing reduced yield drastically. Wheat sowing however, after 20th November can cause a reduction of 15-20 kg per acre yield during each subsequent day. There are two critical periods, during which water stress reduces yield greatly; the period from the development of adventitious roots to the start of tillering, and the period from an thesis to the milk stage. According to an estimate the presence of weeds in wheat fields can reduce 14-42% of the produce. Thus, if 40 maunds of grains per acre are expected, it will reduce up to 23 maunds only. Seed rate for early, medium and late sowing varieties, should be 50, 60 & 70 kg/acre and any change in the seed rate causes substantial yield losses. Nitrogen and phosphorus fertilizers using ratio should be 1.5:1. Crops sown after rice and sugarcane or through tube well irrigated or sandy areas should be supplied with one bag of potash per acre, otherwise yield will adversely be affected.

Wheat crop is damaged by a large number of insects such as grasshoppers, crickets, aphids, army worms, while standing in the field. Grasshoppers and white ants attack plants during the seedling stage, they are more serious in rain fed areas. Aphids and army worms attack the crop in spring after heading, causing considerable losses while the crop is still standing in the field. These pests also eat away the ears, including awns, immature grains, and tillers, tender leaves in the central whorl of the plant and even the older leaves. Rodents cause little damage to the seedling and most of the damage is caused at the ripening stage. Early and late wheat crop is more liable to damage by birds. They eat the seeds before emergence or soon after emergence at planting season. Birds also damage the crop after the dough stage by eating the grain directly from the spikes and by causing some years to shatter completely.

Wheat is also attacked by a number of diseases that cause great losses to the quantity and quality of the produce. Rusts, smuts, powdery mildew and septoria are important diseases that reduce the yield of wheat in different parts of Pakistan. Powdery mildew sometimes attacks wheat in mountainous and sub- mountainous regions. Nematodes also infest wheat, in case of severe infestation, the seedlings may fail to come out of the soil, even if they grow, the infested plants remain stunted and give a shriveled unhealthy appearance. A variable number of grains in an infested ear head may produce galls, which are shorter and thicker than the healthy ones.

Although, they cause little mechanical injury to the plant root, yet their presence stimulate the formation of branched rootlets. The main root remains shorter or bunchy, bearing small galls. In areas, where termites or weevils impose economic problems, the crop should be sown after mixing granular insecticides with soil. If the attack of insects persists, the insecticides can be dusted on the crop. In certain fields, where heavy doses of N and P are applied year after year, symptoms of zinc deficiency may be noted. These symptoms appear on leaves as small white irregular patches. Rodents and birds damage can be reduced to greater extent by the presence of alternative crops, lack of shelter, scaring devices and poison baits. To avoid damage from diseases, resistant varieties of wheat should be grown; seed treatment can also be effective. Nematodes can be controlled by a suitable crop rotation. Gall nematodes can be controlled by separating the galls from the wheat seed by floating them on water in a tub.

Post harvest technology for wheat crop

A plentiful harvest of wheat is only achieved, when all necessary inputs are put together with appropriate production technology. It has been observed that majority of the farmers including progressive growers, who take keen interest in growing high yielding varieties and adopt high production technology right from selection of soil to the harvest of crop, ignore losses those occur at, and after harvesting of the crop. Both wheat grain and straw have tremendous economic value, and is consumed with great desire by men, animals and birds. Some losses at post harvest levels are discussed below:

1. Shattering: Shattering of grains from the arched occurs in the shattering susceptible varieties, before and after harvesting in the field. Substantial losses also occur during lying of wheat bundles and transportation from field to the threshing yard. The cultivation of shattering resistant varieties can be helpful in reducing these losses.

2. Over-drying: Over-drying of the harvested crops in the field, results in shattering and damage by rodents, birds, animals and sometimes by dispersing wind. It is recommended that the crops should be heaped after proper drying in the threshing yard.

3. Delayed threshing: Light to heavy losses may occur, if threshing is delayed. Untimely rains and fast winds may cause severe losses. It is recommended that threshing should be carried out without any delay. While, heaping the materials in threshing yard, it is recommended that earheads should face the centre, so as to prevent losses from periphery damage by animals etc.

4. Improper threshing yards: Improper threshing yard is also responsible for the deterioration of grain and straw quality and losses in productivity. It is recommended that the threshing yard, if not cemented should be at least clean thoroughly, even and free from soil cracks. Losses during threshing: Losses may occur during threshing, if

a) The crop at the time of heaping was not dried properly.

b) The functioning of thresher is not proper.

c) The inadequate skill of the thrasher opera to.

d) The wind velocity and direction of the thresher are not proper;

It is recommended that to avoid losses in threshing, due consideration should be given on the quality of thresher, skillness of the operator, wind velocity etc. Delayed threshing may result into, a)damage by rodents, white ants, birds and animals, b) damage by rains and wind, c) Insecurity from fire and occasional flood etc.

It is recommended that crop after harvesting should be heaped in threshing yard and the process of threshing be completed at the earliest. Losses may occur during bagging, if the quality of bags is not maintained. It is recommended that new gunny bags should be used, and if such bags are not available, then gunny bags in good conditions be used. In that condition, bags may be cleaned thoroughly for other seeds inside to avoid impurities and mixture. It is recommended that bags may be treated with some insecticides such as Malathion to get rid of residues of stored grain pests.

Wheat is to be stored by the producers, farmers and consumers in their homes and by the traders and official agencies in godowns. When this crop is harvested in the field, it is practically free from pest infestation. Grain often infested during the process of transportation, processing and storing.

As a pests of this grain, rodents (rats, mice), birds (especially sparrows) and insects are worth mentioning. Rodents including rats, mice and moles are responsible for causing enormous losses to the stored grains and besides feeding, they destroy a substantial quantity by spillage and contamination with their droppings, urine and body hairs. A rat is estimated to consume about 27 grams of grain daily; in this way they consume several million tons of wheat grain annually.

Sparrow, parakeet, crow, myna and pigeon are destructive and cause much damage by feeding and by causing the grains to shed in the storage.

They also visit the thrashing-floors to feed and use up quite large quantity of wheat. At the time of harvest, wheat grains should be dried to have their moisture contents less than 9 %, which is ideal for storage. Grains kept in damp godowns, absorb moisture from ground or atmosphere. The warm season and high moisture content of grain are highly conducive to proper development and multiplication of insect pests of stored wheat. The insects reach the grains either through the infested gunny bags, receptacles or through the storage of fresh grains in godowns already having infested grains. Within one season, they may destroy 10-15 %of the grains and contaminate the rest with undesirable odors and flavours. There are 4 insects viz., the meal moth, grain moth, rice moth and almond moth belonging to order Lepidoptera; Khapra beetle, red flour beetle, grain borer, gram dhora, mung dhora and rice weevil in the order Coleoptera and mites in the order Acarina.

The damage caused by these pests is the greatest during the monsoon season, when it is hot and humid. Only the larvae of these insects, cause damage by feeding on the grain kernels. The adults are active creatures, capable of short flights and fly about from one bin to another and spread infestation all around. Larval stages bore into the grain and feed on its contents, and about 30-50% of the contents are consumed. If infestation is severe, the devastation is completed, reducing the grain to a mere frass, the grains give out an unpleasant smell and present sickly appearance. Infested grains converted into flour have a characteristic off foul smelling odour.

As a result of destructive activities of stored grain mites, the capacity of wheat to germinate is lowered up to 54%. The most notable result is reduction in protein content. Mites raise moisture contents of the grain generating sufficient heat for the growth of infectious bacteria and fungi.

They contaminate the space between the grains with their dead bodies, cast skins and excrement, thereby hindering the circulation of air in the stock. Flour prepared from such contaminated grains has higher moisture contents, higher acidity and tends to stick together in addition to being cause of diseases. Such wheat flour has fusty smell, bitter taste and deteriorated baking quality.

Control of stored grain pests

Pakistani farmers are very hard working, they are busy all the time in growing tons of grains and fiber in adverse climatic conditions of heat and cold, but unfortunately still, we are not self sufficient in food even. Is it the fault of fortune? No. There are many factors responsible for it to which we are not paying attention. Among these factors non-availability of proper storage conditions is of prime importance.

Losses in storing: Improper storing results in losses.

It is recommended that wheat grain should not have the moisture content higher than 9-12%.

a) The wheat should be stored at some elevated place,

b) the store should have adequate air and sun light entrance,

c) the store should be cleaned and treated with some chemicals to avoid insect pest attack,

d) The store should not have the entrance place for foreign animals such as dogs, cats, birds, rodents etc. as that may spoil the quality and quantity of the stored grain,

e) Gunny bags in the store be placed systematically in lines,

f) After rainy season, the store should be fumigated and if possible, the grain may be sun dried to maintain the proper-moisture percentage.

g) And overall a continuous regular periodical examination of the store and grain is required.

h) Bhusa or straw is not less important than grain, care must be taken for its proper storage.

There are several methods to control stored grain pests, helping to check the spread of harmful insects and mites to markedly reduce their potential of infestation.

1. Quarantine

Some dangerous pests enter in the country along with seed and food grain imported from other countries. So, quarantine measures towards preventing the import of foreign pests should be very strict. The material to be imported should be subjected to laboratory test to detect any kind of pests at the point of entry.

2. Sanitation of stores

Stores should be cleaned. All cracks, holes, crevices etc. should be properly sealed. All granaries, machines and grounds of enterprises must be completely disinfected. All the post harvest wastes should be burnt or buried in soil.

3. Chemical control

Contact pesticides are commonly used on the surface of the floor of stores as dust or emulsion. Fumigants are generally used in hermetically sealed places. They are highly effective, if the necessary concentration is maintained over the required period of time. Among the various methods of controlling stored grain pests, most widely used are chemical methods.

4. Biological control

Lepidopterous pests of wheat can be controlled through natural enemies. Predaceous mites and parasites can control the stored wheat pests e.g. Trichogramma, can control the Angoumois grain moth successfully. In NIA, Tandojam, a biocontrol laboratory is rearing this parasite, but no regular experimentation has been carried out due to lack ofmanpower and facilities. Certain predatory mites, Ichneumonids, brachonid, chalcid, protozons and microbes act as predators and parasites of stored grain pests.

5. Resistant varieties

Research observations have shown that some varieties of different agricultural crops have grain resistant to insect pest attack. Such stock of resistant cultivars may be used to raise the varieties, highly resistant to the stored grain pest infestation.

6. Radiation control

Ionizing radiations have been used by the scientist to disinfest various stored items. Gamma radiation, X-rays, Cobalt and Cesium can be used to combat the storage pests.

7. Use of heat and cold environments

Temperature of 140°F, given for 10 minutes is lethal to most of the stored grain pests. Many insects are inactive below 50°F, grain stored from 40 to 50°F can escape insect infestation. Special precautionary measures should be adopted when grains are kept under temperature treatments as they are deteriorated rapidly.

For the control of bird pests of stored grain, measures should be taken to deprive them of their food and nesting places. For this purpose, covering windows and doors with wire screen, sealing holes &crevices, construction of granaries and warehouses in a way that there is no gap between walls where the birds could nest and rest, are of great importance.

Rodent pest can be exterminated by keeping the grain and grain products dry, rodents should be deprived of water and food, nesting places should be destroyed, all holes should be plugged with concrete and cement and rubbish should be removed regularly. Rats and mice can be caught by using man made traps and cages, and then be killed. Use of natural predators like cats and dogs are fatal to the rats but at the same time harmless to humans and pets. Most effectively and widely methods used to control rats is the use of rodenticides poisoned baits. Fumigation may be done in godowns and rodents burrows. Different combinations of controlling methods may be used suited to individual situation.