Silicon Mitigates The Adverse Effect Of Salt Stress On Growth Of Different Plants

Silicon is not generally listed in the list of essential elements, it is considered as one of the significant beneficial nutrient for plant growth. The quantity of Si in soil may vary significantly from 1 % to 45 %. However, Silicon is present in soil in different forms, but plants can easily absorb Silicic acid Si (OH)4 from soil. Silicic acid is usually found in the range of 0.1-0.6 mM in soils. While Si is valuable for plant growth it plays significant role as a physiomechanical barrier in the majority plants.

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Erum Rashid 1 , Muhammad Adnan Shahid 1 , Muhammad Ahsan 2
1 College of Agriculture University of Sargodha, 2 Cholistan Institute of Desert Studies, The
Islamia University of Bahawalpur.

While its facts on cell walls, its active association in a large number of metabolic processes and physiological, is also apparent. Plants deprived of Si often Show poor development and reproduction, but it depends on the type of plant species. For plant growth and production salinity stress is one of the most destructive stressful environments. One possible approach of overcoming the salt-induced deleterious effect on plant growth is the exogenous application of inorganic nutrients and osmo protectants.

By adopting this approach, the supplements of Si to plants subjected to the salt affected soils, because Si has been considered valuable for improving crop tolerance to both abiotic and biotic stresses. According to different investigation the ameliorative role of Si to adverse effects of salinity has been examined in different crops e.g., cucumber, tomato, wheat, rice and barley.

Silicon uptake in the form of uncharged molecule-silicic acid and in plants three different modes of silicon taken up (active, passive, and rejective) may function. In aerial parts of plants silicon distribution is dependent on intensity of transpiration. During the transpiration stream in xylem, silicic acid is transported to leaves and it is accumulated in older tissues. In the shoot, due to the loss of water, silicic acid is concentrated and polymerized

Demonstrating the advantageous effects of silicon appliance in improve salt-induced harmful effects on growth of plant. Decrease in plant photosynthesis under salt stress take place due to closing of stomata that reduced photosynthetic rate leads to reduced plant growth in the majority of plants. Under salinity the closing of stomata that result in decrease in leaf internal CO2 concentration and reduced leaf transpiration rate.


Silicon-induced improvement in plant growth under salt stress may have been due to the important role of Silicon in the improvement of plant water status. Silicon affects plant growth under stressed conditions by affecting a variety of processes including the improvement in plan water status, changes in ultra-structure of leaf organelles, up regulation of plant defense system and mitigation of specific ion effect of salt.

Silicon application to saline medium enhances the photosynthetic activity, chlorophyll content and ribulose bis-phosphate carboxylase (RUBP) activity in leaf cell organelles and also minimizes the salt-induced H2O2 production. Exogenously applied Si improved all those parameters both under non-saline and saline regimes. The other mechanisms for salinity tolerance induced by Si application are; enhanced bioactive gibberellins (GA1 and GA4) contents and reduced jasmonic acid (JA) contents under salinity stress. Si application under saline conditions, detoxifying ROS enhanced under salt stress; as a result chlorophyll increases which lead to the improve (Fv/Fm).

According to different investigations the decrease in value of (Fv/Fm) with salt application and increase in (Fv/Fm) with Si application under abiotic stress might be due to less photoinhibition; where Fv/Fm has a significant positive correlation with A and SPAD values. Salinity stress imposes injurious effects on plant growth, its photosynthetic activity and photochemical efficiency of photosystem II, Silicon application improved all parameters under salt stress by enhancing the A, gs and WUE under salt stress.

Silicon treated plants have higher photochemical efficiency of photosystem II which leads to healthy growth under salt stress conditions. Thus, Si application would be beneficial under salt stress conditions and its beneficial effects should be tested on a larger scale i-e field conditions.

Sustainable management of helicoverpa armigera hubner on sunflower, helianthus annus l.

Twenty diverse genotypes of sunflower helianthus annus L. were exposed to naturally occurring population of H. armigera under preliminary screening trials. Nine out of twenty comprising three each resistant, moderately resistant and susceptible were selected on the basis of egg count and larval infestation. The layout of the experiment was a RCBD with four replications. These selected genotypes were further sown for further experiments. Data for various physico- morphic plant characters was taken at different stages of the growth of the crop.

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The nine genotypes were subject to laboratory analysis to find out the chemical plant characters as part of host plant resistance. Various physico- morphic and plant chemical characters and their correlation with eggs and larval population of the pest was studied. Data regarding temperature, rainfall and humidity was taken during the growing period of the crop. Correlation of weather factors with population build up of H. armigera was also studied. Data regarding egg and larval population, physic- morphic, chemical plant factors and weather factors was subject to multiple regressions to find out the basis of host plant resistance. One comparatively resistant and relatively susceptible genotypes (G53) and (ORB-100) were subject to experimentation for evaluation to different pest management techniques and data were taken before and after the application of treatments on these genotypes.Yield data on the basis of heads of genotypes was taken to know the impact of these treatments on resistant and susceptible genotypes. Genotype (G53) showing potential on all other genotypes, when different set of treatments were applied as part of sustainable pest management methods. Cost benefit ratio of each treatment was compared There was significant difference among the treatments C:B ratio.Our investigation showed potential for developing H. armigera resistant genotypes that would reduce seed feeding injury, prevent yield loss and increase growers profit.

Author: ZAFAR, KHALID

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Effect of viruses on photosynthesis

The most obvious symptom of systemic virus infection is the mosaic pattern of the leaves. Yellowing, chlorosis is also frequent and characteristic sign of the altered photosynthetic activity. Virus infection effects photosynthesis in a complex manner, depending on the particular host-virus combination. The symptoms are basically different in the incompatible or the compatible host-virus interaction. 
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Hafiz Muhammad Rizwan Mazhar

                  Department of Plant Pathology, University of Agriculture, Faisalabad-Pakistan

 

                                             (E-mail: rizwanmazhar0

[/ads-quote-center]84@gmail.com)

Photosynthetic changes in incompatible host-virus interaction Virus infection often causes local lesions in resistant plants. The development of local lesions in hypersensitive reaction (HR) was described in details by electron micros- copy, based on the time course of the appearance of symptoms. The ultrastructure of the lesion and the surrounding cell layers and the role of the active zone in the localisation of the infection was highlighted (Israel and Ross, 1967).

In tobacco mosaic tobamovirus (TMV) infected N. glutinosa leaves the size and number of the starch grains increased in the chloroplasts following the infection (Weintraub and Ragetli, 1964). One day after the infection plasmolysis occurred, and first the cytoplasm and later the chloroplast membranes completely disappeared.

 In the remains of the chloroplasts large vesicles were formed, the number of mitochondria increased and their structure changed. Finally the whole cell structure collapsed and its content disin-tegrated. All these alterations were consequences of the loss of osmotic regulation, and have been related to the so-called ‘starch-lesions’ described by Holmes (1931).

Photosynthetic changes in compatible host-virus interaction For the synthesis of virions the parasite uses the metabolites and energy of the host plant, which are produced in the course of photosynthesis. It is evident that the phy- siological processes of the virus and the plant are linked in complex ways, the structure and the function of the chloroplasts are disturbed (Zaitlin and Hull, 1987).

Changes in the ultrastructure of chloroplasts

The chlorosis of leaf tissues in the compatible host parasite interactions can be traced back to different causes. The number, size or chlorophyll content of the chloroplasts may decrease.Their shape, inner membrane structure may alter to some degrees, some of their metabolites may accumulate. Often the starch grains enlarge, or accumulate for example in the case of the cauliflower mosaic caulimovirus (CaMV) infected cabbage plants (Conti et al., 1972).

Effect of virus infection on CO2-fixation and on some biosynthetic processes 

In several virus-host interactions the disturbances of CO2-fixation and of related metabolic ways, or the alteration in ratio of certain products was reported. At the early stage of systemic TMV infection (virus replication) more CO2molecules assimilated by the photosynthetic processes (Doke and Hirai, 1970a). As the infection had been progressed this tendency inverted: CO2-uptake was decreasing in the infected.

 The same changes as well as the increase of res-piration were observed in tobacco leaves infected with tobacco etch potyvirus (TEV).The enzyme activity of phosphoenol-pyruvate-carbox-ylase (PEP-carboxylase) increased in the leaves of chinese cabbage infected with TYMV.

In contrast, in tobacco leaves infected with TSWV activity loss of PEP-carboxylase was measured and it was explained as the early senescence induced by the virus infection.

Changes in the chlorophyll protein complexes and chloroplast proteins

Virus infected monocotyledons (e.g. barley infected with BSMV or WSMV) contained reduced amount of chlorophyll protein complexes compared to the healthy controls.

Effect of virus infection as a biotic stress factor on photosynthesis

Stress has been described by Osmond et al. (1987) as all parameters that suppress the maximum, potential genomial value of growth and reproduction of a plant. Plants adopt to stress conditions in two ways, either by tolerance or avoidance. In the case of tolerance the plant’s reaction to a moderate stress is the upregulation, while against a severe stress the down regulation of metabolic processes.

At the cellular level the damage in the membranes and the fluorescence of chlorophyll built in the thylakoid membranes indicated the post stress conditions. In the early phase of virus infection both the non-photochemical quenching of fluorescence and the predominantly reduced state of QAthe primary electronacceptor of PSII, indicated the development of symptoms and the rapid chloroplast destruction due to photoinhibitory conditions (Balachandran et al., 1997).

 

 The build up of carbohydrates and the brakeup of the equilibrium between synthesis and brakedown probably blocks the gen regulation, which effects the level of chlorophyll-protein complexes and photosynthetic metabolic enzymes.

 

Technology transfer for cucumber (Cucumis sativus L.) production under protected agriculture in uplands Balochistan, Pakistan

The adverse climatic conditions and scarcity of irrigation water in Balochistan (Pakistan) have encouraged the development of protected agriculture. Semicircular plastic tunnels were introduced in three districts of Balochistan. This technology transfer trials have shown the advantages and benefits of producing cucumber in tunnels with marketable yield per unit area between 5.37 to 6.77 kg m2.
Farmer-managed  trials  also  confirmed  better  effectiveness  and  efficiency  of  protected  agriculture tunnel against insect pest of cucumber grown under tunnel. The cucumbers so harvested were of higher quality (no insect damage) and were sold at premium prices during the whole production cycle. Proper crop sequencing by considering the market situations as well as physiological circumstances are important for successful production of high value crops including cucumbers round the year.
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These decisions should be based on the market demand and consumer preference analyses. Higher technical knowledge is also required to manage plant nutrient requirements, choose right kind of hybrids and irrigation scheduling, maintain temperature and humidity and take proper plant protection measures.
Key words: Cucumber production, protected agriculture tunnels, cost benefit ratio, technology transfer, upland, Balochistan

AzeemKhan1,MuhammadIslam2,InamulHaq3,Sarfraz Ahmad2,GhazanfarAbbas1and

MohammadAthar4*

 

1Pakistan AgriculturalResearch Council, Islamabad, Pakistan.

2AridZone Research Center,BreweryRoad,Quetta,Pakistan.

3Agriculture Research Institute,Sariab Road, Quetta,Pakistan.

4California DepartmentofFood and Agriculture,3288MeadowviewRoad,Sacramento,CA95832,USA.
Introduction:

Balochistan with an area of 34.7 million ha, represents 43% of the total area of Pakistan. The province has four distinct  types  of  climates;  coastal  (sub-tropical),  arid, hyper  arid,  and  temperate,  with  a  great  diversity  in altitudes and annual mean temperatures. The altitudes range from sea level to 1,800 m above sea level, and the mean monthly temperatures fluctuate from  sub-zero in the winter months of December to January to super high (45 to above 50°C) in the summer months of  May to July/August (Kidd et al., 1988). Annual precipitation fluctuates widely across the  province;  not  only  within a normal  year  but  precipitation amounts are  also  erratic over a longer period of time (Athar, 2005).
Agriculture sector is the backbone of the economy of Balochistan, as it contributes about 32% of the provincial Grass Domestic Product (GDP). Agricultural outputs in the province have been expanding particularly since the mid 80’s until towards the end of 90’s when the impact of drought started causing significant decline on the overall output. Since 1998, total production of all crops has declined at an alarming rate of about 8% per year. At the same time, yields of most crops remained low as compared to other provinces or even other developing countries. The fluctuating level of water availability in the uplands is one of the several causes of  relatively low yields of key vegetables. Inefficient use of irrigation water also adversely affects the per unit productivity of crops  in the Balochistan province. As per government policy, and now with the availability of electricity at subsidized rates, there has been a tremendous increase in the number of tube wells.
However, as the conventional sources of water in the province   were   shallow   wells,   karees   and   springs therefore, indiscriminate installation of tube wells and pumping of  water  in excess of  recharge have caused lowering of water table resulting in drying of dug wells, karees and  springs (70%).  The  excessive  pumping  of ground water has caused serious concerns regarding the sustainability of irrigated agriculture. Since 1998, the International Centre for Agricultural Research in the Dry Areas (ICARDA) since 1998, has been involved in the development of protected agriculture in the water scarce countries of the Arabian Peninsula. Thus, they have initiated  the  same  activities  in  Balochistan  under  the project “Food Security/Poverty Alleviation in Arid Agriculture Balochistan” – Pilot Project Phase. The plantation  of  cucumber  in  tunnels  was  one  of  the initiatives taken under this project.
Advantages of protected agriculture (PA)
Protected agriculture (PA) has the potential to contribute significantly to both the development of rural communities and to devise sound water policy for the production of high value crops of Balochistan. It can play an important role in supplying local markets with fresh produce that could   not   be   grown   otherwise,   and   in   creating employment within rural communities and productive opportunities for the disadvantaged, particularly women. It  also  offers  potential  for  development  of  a  private service sector in the construction and supply of protected agriculture equipment and inputs such as seeds and fertilizers. Ultimately, high yielding quality produce from protected agriculture could be expanded to serve the export market and generate a valuable source of foreign currency.
PA with its associated production systems can significantly reduce the amount of water and chemicals used in producing high value fresh produce compared to open field production. The comparative advantages of PA over open field production may include:
1. Crops can be produced year round regardless of season, so multiple cropping on the same unit of land is possible. Farmers can benefit of market seasonality to produce off season crops to earn higher prices.
2. PA allows the production of high quality and healthy seedlings  for  transplanting  to  open  fields,  supporting earlier cropping and stronger, more resistant crop stands.
3. Protective housing provides protection for high value crops from unfavourable weather  conditions,  pests  and diseases.
4. Use of PA can increase production by more than five fold, and increases productivity per unit of land, water, energy, and labour.
5. PA supports the production of high quality and clean products.
The strategic focuses of the current government plans are to augment and promote efficient use of limited underground water resources. PA initiative in this project was taken to examine the feasibility of water resource efficient high value agriculture. ICARDA has previously used this technology with farmers in Yemen and Afghanistan with promising results. There is substantial evidence that the PA technology is economically viable in the context of Afghanistan as well. In case of cucumber cultivation under PA, for example, its production in the spring of 2005 generated an additional farm income of Afs 13,200 to 78,000 per grower (ICARDA, 2006).
In Yemen, cucumber productivity was 17-fold greater under PA, while tomato reached 12-times its productivity as compared to open fields (Amin et al., 1998). Oweis (1990)  studied  cucumber  yield  response  to  different levels of irrigation and concluded that maximum yield of 946 tons/ha was produced with 223 mm of water consumed as transpiration. Thus, water efficient techniques of protected agriculture were successfully introduced by ICARDA to small landholders in the rainfed mountainous terraces of  Yemen and Afghanistan,  and the experience gained was transferred to Balochistan.
The overall aim of this study was to alleviate poverty and generate rural incomes, by promoting the adoption of affordable and sustainable Protected Intensive Produc- tion System (PIPS) to produce high value crops, using marginal or  otherwise non-productive lands.  The other objective was to estimate the economic feasibility of vegetable production under farm situations. The initial investment and operational cost were accounted for to estimate the gross revenue, total costs and net returns for the production and marketing of cucumber crop.
MATERIALS AND METHODS
In  2006,  four  galvanized and  polyethylene (PE)  covered  green houses (9×30 m) having side and roof ventilation facilities were installed for vegetables production in three districts of Balochistan (Mastung, Killa Saifullah and Loralai). Generally, a large majority of growers liked this type of non-cooled greenhouse due to its simplicity and ease of construction. Tomato, squash and hot and sweet  pepper  were the  main  crops  cultivated  in  these  houses during the cool and mild seasons (Athar and Bokhari, 2006) but for the   purpose   of   this   experiment   cucumber   cultivation   was considered due to  its  likely most  economical crop  under these tunnels.
A white net was used on both side of  the tunnel to avoid  any insect damage and vectoring of diseases. In each tunnel, four rows were prepared with the distance of one meter. The total duration   of the  crop   was   around   100   to  120   days.   In  summer   months, Limestone  washing  method  was  used at the roof for lowering  the temperature   during   day  time.   Irrigation   was   done  with  trickle- irrigation. T-tubing was installed underneath the black plastic mulch with   minute   punctures   for   the  water   out-let   near   each   plant. Cucumber  Queen-1  variety was planted  at all sites. The seed was imported from a Dubai based “Royal Sluis” company due to its good quality  and  high  yielding  reputation.  Triple  super  phosphate  was applied    before    planting.    Compound    soluble    NPK    fertilizers (nitrogen, phosphorus and potassium)  were applied after 15 days of germination  at the recommended  rates with irrigation  on alternate days.
Plants were individually  trellised on twine hung from a horizontal support.  Plastic clips were used to attach the vines to the twine at the base of the plant  and along the vine to support  the fruit load. Cucumbers  were pruned to a single stem with no lateral branches (suckers).  Fruits  were removed  up to the 6th to 8th node and the plants were then allowed to set one fruit per node every other node up  to the  horizontal  support.  At  the  top  of the support  wire,  two laterals   were  trained   over  the  wires.   However,   cucumbers   set multiple fruits at each node and on the lateral branches, so both the fruit and lateral branches were left on the plant after the 8th node to avoid  excessive  vegetative  growth  and  lateral  branches  were pruned at  the second node  on  the lateral.  Disease and  insect controls were monitored continuously as per recommended practices. The poor quality fruit were removed before maturity which also helped in maintaining continuous fruit set. Cucumbers were harvested at a diameter of 4 cm or less.
For the purpose of cost-benefit ratio analysis, all costs including initial investment on protected agriculture (PA), its installation cost, variable cost of cucumber production and fixed costs were accounted. The PA was constructed near tube well water already installed by the farmer. However, a water pump and water tank was put  in  place  for  irrigation  purposes.  The  irrigation  supply  was metered to estimate the m3  water usage during crop production period. The field was thoroughly ploughed with the tr actor before installing PA.
Fixed  costs  were  included  as  interest  (7%)  on  total  initial investment, annual initial investment cost (4 months) and interest on total variable cost (7%). Variable costs covered ploughing, ridge making, seed, fertilizers, pesticides, micro-nutrients, picking labor, haulage and packing costs. Administrative costs were estimated for managing  production  operations  and marketing  of produce. Depreciation  of PA was estimated by using the straight-line method. Assets  were divided  by their useful life expectancies  to determine annual  cost  for  depreciation.   The  land  rent  was  ignored  in  this study,  as  land  used  for  the installation  of  PA  was  not  previously under use for agriculture purposes.
Thus, total production  costs of cucumber  production  in PA were the  combinations  of  fixed  costs,  variables  and  managerial  costs. The net returns  were estimated  by subtracting  total costs from the gross  revenue  of cucumber  produced  and sold  at different  prices during the whole production cycle. Monthly average weighted prices were used to estimate gross returns from the total production.
RESULTS AND DISCUSSION Investment and variable costs
The initial investment costs, annual costs, variable costs and total costs of  cucumber  production in tunnels are presented in Tables 1, 2 and 3, respectively. Initial investment costs were calculated to be US$ 2,792 for 270 m2 tunnel or US$ 10.3 per m2. About three fourth of the initial investment cost was comprised of galvanized frame, plastic covering and insect proof net. Annual initial investment cost was US$ 187. It was assumed that three crops could be grown by the farmers under mild temperature  conditions  prevailing  during  the  summer season.  As  cucumber  cultivation  was  completed  in  4 months period,  therefore,  annual  investment  cost  esti- mated of US$ 62.3 was estimated.
Low cost low tunnels are presently used in Balochistan to grow tomato nurseries for early planting only. Such low tunnels are very commonly used around Nowshera area of Khyber Pakhtoon Khawah province of Pakistan to grow off-season cucumber and squashes. The cost of polyethylene sheets and sticks used to cover cucumber during early growth stages is estimated around US$ 208 per ha  (Adnan,  2006;  Ishaq  et  al.,  2003). Under low tunnels, cucumber yields were 3.7 kg, total cost   US$ 0.32,  and  net  benefits  US$  0.23  per m2  on farmers’ field in Nowshera area of Khyber Pakhtoon Khawah province (Adnan, 2006).
Ordinary high tunnels were conventionally used by the research system to explore the possibilities of growing off-season vegetables including cucumber, tomato and sweet peppers. Chaudhry et al. (2003) tested 11 cucumber  hybrids  growth in tunnels during  winter  season  in rainfed Pothwar.  The use of  high tunnels either made with local materials like bamboo sticks or PVC pipes and plastic covering is becoming increasingly popular in the Punjab  province  of  Pakistan.  Use  of  high  efficiency tunnels  is  a  rare  phenomenon  and  limited  with  some hybrid  seed  importer  for  testing  new  hybrids  and  to demonstrate the commercial production of high value off season  vegetable  crops.  The  cost  of  material  used tunnels, cucumber yields were 3.7 kg, total cost   US$ 0.32,  and  net  benefits  US$  0.23  per m2  on farmers’ field in Nowshera area of Khyber Pakhtoon Khawah province (Adnan, 2006).
Ordinary high tunnels were conventionally used by the research system to explore the possibilities of growing off-season vegetables including cucumber, tomato and sweet peppers. Chaudhry et al. (2003) tested 11 cucum- ber  hybrids  growth in tunnels during  winter  season  in rainfed Pothwar.  The use of  high tunnels either made with local materials like bamboo sticks or PVC pipes and plastic covering is becoming increasingly popular in the Punjab  province  of  Pakistan.  Use  of  high  efficiency tunnels  is  a  rare  phenomenon  and  limited  with  some hybrid  seed  importer  for  testing  new  hybrids  and  to demonstrate the commercial production of high value off season  vegetable  crops.  The  cost  of  material  used compared with Afghanistan PA established by ICARDA in 2005,   where   the  cucumber  yield for  a  square  meter ranged from 1.9 to 12 kg on average 5.3 kg/m2 (ICARDA, 2006). The low yield was observed at Saddiqabad due to 12 to 16 h of load sheding in the area which affected the availability of water. It must be noted that this income was from two cropping seasons and these tunnels could be utilized for at least three cropping seasons per year. Although the initial cost of materials for tunnel may be high, farmers will be able to recover this cost in the long run,  as  they  continue  using  the  tunnel  over  several growing seasons. Plant disease remains the leading drawback for greenhouse vegetable production (Dinham, 2003).
Cucumbers were marketed in the nearby town market of Mastung, Killa Saifullah and Dukki. The produce was transported instantly after harvest in plastic crates. The cucumber produced in PA was clearly distinguished from the open field produced ones. Therefore, disposal of produce was quite easy even in a small local market. The produce was easily distinguished by the buyers and sold at premium prices during the whole production cycle. The prices in the local market were negotiated on per crate basis that is equal to 18 kg weight. The average premium received per crate was around US$ 2 (30 to 40% higher prices)  per  crate.  During  the  peak  supply  periods  of August, prices received were lower and increased significantly during September and October months. Average  prices  received  ranged  between  US$0.30  to US$ 0.46 per kg. About 58% cucumber was sold at US$ 0.30 per kg and the rest was sold at higher prices (Table 4).  It  could  be concluded that marketing  of  cucumber produced in tunnels was readily  accepted in the local market. Buyers were found willing to pay a 30 to 40% price premium for the tunnel produced high quality delicious cucumbers.
Sensitivity  analysis  of  minimum  yield  to  achieve break-even A sensitivity analysis is one of the better alternatives to understand  uncertainty in any type of  financial model. Sensitivity analysis shows the financial situation of a certain enterprise when produce price changes or input prices change (Weinberger and Lumpkin, 2005). For the successful greenhouse production, it is important that produce’s price covers at least the unit production cost.
Based on current production costs inside 270 m2 greenhouse and because growers cannot influence the market price, a sensitivity analysis was conducted to indicate the minimum yield required at a given market price to cover production costs (Chaudhry and Ahmad, 2000; Dinham, 2003; Hussain and Hanif, 1990). The results showed that cucumber producers should target yields above 700 kg for summer sales when prices could be as low as US$ 0.35 per kg. In the winter yield should be above 260 kg when the price is expected to be more than US$ 0.70 per kg (Figure 1).

Table1.Initialinvestmentforprotectedagriculturetunnelconstruction.

 

 

Item

Initialcost(US$)

%

Usefulllife year

Annualcost(US$)

%

Galvanizedframe

1471.4

53

20

73.7

39

PlasticCovering

367.8

13

10

18.4

10

Insectproofnet

313.4

11

20

15.7

8

Blackplasticmulch

46.3

2

2

23.2

12

Sockets,  valves,  pipes,  elbow etc.

 

118.2

 

4

 

10

 

11.8

 

6

TTapesand PVC pipes

108.1

4

10

10.8

6

Watertank

133.3

5

10

13.3

7

Waterpump

100.0

4

15

6.7

4

Site preparation

50.0

2

10

5.0

3

Assembly

83.3

3

10

8.3

4

Total

2792

100

 

186.8

100

Persquaremeter

10.3

 

 

0.7

 

Gross revenue and net returns
Total  gross revenue  earned from  producing  cucumber under PA was estimated to be US$ 623 (Table 5). Total cost of cucumber production was estimated to be US$ 308. A share of variable and fixed cost in total cost was almost identical. Net returns were estimated to be US$ 315. Net returns per square meter were estimated to be US$  0.37.  Total  irrigation  water  resources  used  to produce 1183 kg cucumber was 39 m3. Net return per cubic  meter  water  was  estimated  to  be  US$  2.88, whereas  in  Afghanistan  it  reached  US$  3.68,  which clearly indicated the potential to also improve water use efficiency in Balochistan.

Table2.Variablecostforcucumberproductioninprotectedtunnels.

 

 

Parameter

Unit

Rate(US$)

Amount(US$)

Totalcost(US$)

%

Tractorploughing

Hour

5.0

2.0

10.0

7

Ridgemaking

Manday

3.3

1.0

3.3

2

Seed

No

0.1

595.0

49.6

33

Fertilizer

Kg

0.8

28.4

23.4

15

Irrigationlabor

Manday

1.7

13.3

22.1

15

Electricitycharges

Percubicmeter

0.3

39.0

13.0

9

Pickinglabor

Manday

1.7

4.1

6.9

5

Pesticide

Cost

1.0

6.7

6.7

4

Micronutrients

Cost

1.0

3.1

3.1

2

Haulage

Cost

1.0

11.0

11.0

7

Packingcost

Crate

0.4

5.0

2.2

1

Total

 

 

 

151.2

 

Persquaremeter

 

 

 

0.6

 

Conclusions and recommendations
Vegetable production in high technology tunnels is a challenging task on technical as well as economic accounts. Proper crop sequencing by considering the market situations as well as physiological circumstances are  important  for  successful  production  of  high  value crops round the year. These decisions should be based on the market demand and consumer preferences analyses. Higher technical knowledge is required to manage  plant  nutrient  requirements,  choose  the  right kind of hybrids and irrigation scheduling, maintain temperature   and   humidity   and   take   proper   plant protection measures. The project has achieved some milestones in the introduction of water use efficient PA that includes:

Table3.TotalcostofcucumberproductioninPA.

 

 

 

Parameter

Totalcost

          (US$)           

 

 

   %   

Variablecost

151.2

 

49

Fixedcost

 

0

Interest     on     total     initial investment

 

64.5

 

 

21

Annualinitial investmentcost

61.6

 

20

Intereston totalvariablecost

10.6

 

3

Subtotal

137.7

 

44

Managingcost

20.0

 

6

GrandTotal

307.9

 

100

PerSquaremeter

1.14

 

 

(i)  Exposure  of  scientific  cadre  to manage  high value crops in tunnels;
(ii) Training of technicians in assembling and installing of all components of tunnels at farmers fields;
(iii) Understanding on forming beds and planting crops with mulching;
(iv) Controlling high temperature during summer; (v) Handling pest problems; and
(vi) Adjusting the use of soluble NPK by considering crop condition at different growth stages.
The  PA  farmers  and  researchers  are  linked  to  seed dealers dealing with the supply of  hybrids who supply after testing these seeds at their own farms. The hybrid dealers also have vast experiences of growing vegeta- bles under tunnels at commercial scale. These linkages would benefit the research system of Balochistan through sharing  their  experiences  and  also  provide  low  cost viable hybrid seeds tested under local circumstances.

Month

Yield(kg)

Price ($/kg)

February to June

1080

0.299

JulytoOctober

750

0.401

Total

1830

0.350

PerSquareMeter

6.77

2.31

 

 

Table4.TotalgrossrevenueobtainedfromcucumberproductioninPA.
 

 

The net returns from cucumber production under PA shows its feasibility even with low level of technical knowledge during initial experimentation phases. Vegetables are exported from Balochistan for 4 months and during the remaining 8 months imported from other provinces. The consumer at the local markets located at Mastung, Killa Saifullah and Loralai districts can easily distinguish between the quality of produce from PA and open fields. Consumers are also ready to pay premium for the quality products produced under PA which shows potentiality  of  increasing  high  value  crops  production under high tech tunnels. Higher net returns obtained for per cubic meter of water used to produce high quality cucumber, further suggest the expansion of high value crops production under PA.
REFERENCES
Adnan P (2006). Comparative analysis of seasonal and off Cucumber in Nowshera, Charsadda and Malakand areas of NW FP. Department of Agricultural   Economics,   Faculty   of   Rural   Social   Sci.   NW FP Agricultural University, Peshawar, Pakistan
Amin AH, Al-Kirshi T, Abbas AM (1998). Protected agriculture in the Republic of Yemen. {Moustafa A, Al Mohammadi A, Abou-Hadid A and  Peacock  JM,  (eds.)}.  Proc.  International  W orkshop  15-18 February 1998. Doha, Qatar.
Athar M (2005). Nodulation of native legumes in Pakistani rangelands. Agric. Consp. Sci. 70: 49-54.
Athar M, Bokhari TZ (2006). Ethnobotany and production constraints of traditional and commonly used vegetables of Pakistan. J. Vegetable Sci. 12: 27-38.
Chaudhry MF, Khokhar KM, Jeelani G, Ullah U Riaz S (2003). Performance of some cucumber hybrids/lines under plastic tunnel. Sarhad J. Agric. 19: 493-495.
Chaudhry MG, Ahmad B (2000). Pakistan. In: Dynamics of  vegetable production, distribution, and consumption in Asia. {Mubarik A (ed.)}.
Asian Vegetable Research and development Center (AVRDC), Shanhua, Taiwan, AVRDC Publication No. 00-498. pp. 271-302.
Dinham B (2003). Growing vegetables in developing countries for local urban populations and export Markets: Problems confronting small scale producers. Pest Manage. Sci., 59: 575-582.
Elahi M, Khan MJ, Rehman H (1983). Rural Labor Market with special Reference to hired labor in Pakistan’s Punjab. Punjab Economics Research Institute, Lahore.
Hussain  AR,  Hanif  M  (1990).  Vegetable  research  in  Pakistan.  In:
vegetable research and development in south Asia; { Shanmugasundaram S (ed.)}, Asian Vegetable Research and development Center (AVRDC), Shanhua, Taiwan, AVRDC Publication No. 90-331. pp. 52-57.
ICARDA  (International Center  for  Agricultural  Research  in  the  Dry
Areas).  (2006).  Introducing  protected  agriculture  for  cash  crop production in marginal and water deficit areas of Afghanistan. Final Report. ICARDA, Aleppo, Syria.
Ishaq M, Sadiq G, Saddozai SH (2003). An estimation of cost and profit functions for offseason cucumber produce in district Nowshera. Sarhad J. Agric. 19:155-161.
Kidd CHR, Rees DJ, Keatings JD, Rehman F, Samiullah A, Raza SH (1988). Meteorological data analysis of Balochistan. Research Report No 19. AZRI/ICARDA, Quetta, Pakistan.
Oweis TY (1990). Irrigation management of plastic house cucumbers. Dirasat. 17B: 59-71. W einberger K, Lumpkin TA (2005). Horticulture for poverty alleviation-
The unfounded revolution. Asian Vegetable Research and Development Center (AVDRDC), Shanhua, Taiwan, AVRDC Publication No. 05-613, W orking Paper No. 15. p. 20.
 

Principles and Practices of Seed Production

Flowering is a prerequisite for seed production. It starts after floral induction which provokes a meristem to start flower bud formation (also referred to as flower initiation) after certain internal or external signals. Plant age or size and more specifically endogenous level of certain hormones are considered as internal cues; while, length of day/night and low temperature are external signals. These external stimuli allow synchronized flowering in a population at optimal time during a year to ensure successful pollination and seed setting before inclement weather conditions. In some conditions, two different developmental signals are required in succession, such as, two different photoperiods or low temperature treatment (vernalization), followed by certain photoperiod. Vegetables and flowering annuals vary in their vernalization and/or photoperiodic requirements to pass from juvenile (vegetative) phase to reproductive phase, which is a transitional process. For some species, vernalization (exposure to low temperature) is obligatory for flower induction and differentiation. These species are biennial and cannot start flowering without completion of their vernalization for examples, crucifers (cabbage, Chinese cabbage, cauliflower, turnip, kale, and kohlrabi), carrot (European types), onion, red beet, parsnip, celery and lilium (Lilium logiflorum). In such species, vernalization and day length synergistically promote floral induction. Some obligate species such as celery, globe artichoke, and carrot, require short days during vernalization for floral induction and long days after vernalization (during flower differentiation). While, some other species have facultative vernalization requirement and cold exposure is required just for flower induction and flower differentiation, and bolting is regulated by long days. In facultative vernalization requiring species, long days also compensate for unstable vernalization due to very short exposure to cold temperature. Examples of facultative species are leek, broccoli, radish, spinach, lettuce, and peas.
Usually, a temperature of 0–5°C is required to fulfill vernalization requirements of several crops. Higher vernalization temperature can results in delayed, incomplete and/or poor flowering, even de-vernalization in some species. However, summer cauliflower and broccoli can flower at 20-30°C without vernalization. Onion requires 2-13°C, temperate types vernalize at low temperature, while tropical types can vernalize at 9-13°C. Several vegetables and herbaceous (annual flowers) species respond to vernalizing temperature at certain developmental stage. Most of the crucifers can be vernalized when stem diameter is 10-15 mm. Carrot, onion, cauliflower, cabbage, coreopsis (Coreopsis grandiflora), gaillardia (Gaillardia × grandiflora), rudbeckia (Rudbeckia fulgida) and tobacco must have 8-12, 4-7, 4-12, 4-15, 8, 16, 10, 37 leaves, respectively, to respond to vernalization temperature.
Seeds of some crops, if exposed to low temperature during imbibition, can be vernalized, for example lettuce, turnip, spinach, Chinese cabbage, red beet, and white mustard (Sinapis alba L.). Exposure of ripening beetroot seeds (on the mother plant) to low temperature can also reduce the vernalization requirements. Moreover, vernalization requirement (duration of exposure to low temperature) of various cultivars of a crop are different. Therefore, sowing time should be adjusted according to the vernalization requirements i.e. cultivars requiring prolonged exposure should be planted earlier than those requiring short exposure time.
Vernalization response is common in winter annuals and biennials. Summer vegetable crops and summer annuals (flowers) usually require long days. Cucurbits are long day plants but, long days and high temperature promote production of staminate flowers and mild temperature and relatively short days promote gynoecy (femaleness). Flowering in short day plants, the native of low latitude on both sides of the equator, starts when day length is less than a particular critical time. Amaranth (African spinach), chrysanthemum, and poinsettia are short day plants.
Some vegetables like eggplant, tomato, cucumber and watermelon do not have specific day length requirement for flower initiation. Although cucumber is day insensitive but, long days promotes maleness and short days favour gynoecy (femaleness). Similarly, Asiatic carrot cultivars under long day conditions behave as annual and do not require vernalization temperature. In some crops, such as radish, cultivars without vernalization and specific day length requirement flower earlier when grown under long day conditions. So, for successful seed production, one must be familiar with photoperiod and low temperature requirements of crop(s). Other components of climate, such as irradiance and precipitation, also have significant role in flowering. Length of juvenile period can be reduced in pelargonium (Pelargonium × hortorum) by increasing the irradiance, through supplemental lighting or by providing growth promoting conditions (Armitage and Tsujita 1979). 

Among other climatic requirements of flowering and seed setting is the prevalence of suitable temperature and absence of rainfall during flowering. Continuous rainfall during flowering can wash out stigmatic fluid and suppress anther dehiscence. High as well as low temperature can result in slow growth of pollen tube and/or embryo abortion. Increase in average daily temperature reduces number of flowers per inflorescence, e.g., in Pelargonium spp. Temperature during seed maturation can also affect germination. Some seeds have higher germinability when matured under higher temperature, while others showed more germination when matured at lower temperature. This effect is due to pre-conditioning effect of high or low temperature on seed development.

Comparative Effects of Salicylic Acid and Calcium Carbide on Some Morphological and Physiological Parameters of Sweet Pepper

Calcium carbide (CaC2) has occupied an important position among different sources of ethylene (C2H4) for improving growth and yield of vegetables. Calcium carbide dependent C2H4 can cause noteworthy improvements in growth, yield and fruit quality of vegetables but its effect on physiological and morphological parameters of vegetables is completely concentration dependent. Under critical environmental conditions, an abrupt release of C2H4 from CaC2 can impede growth and yield of a crop as it initiates leaf, flower and fruit senescence and finally great loss of yields. However, CaC2 dependent released C2H4 can be more constructive and worthwhile for non-conventional production of vegetables if it is applied along with salicylic acid (SA). Salicylic acid not only impedes C2H4 biosynthesis but also plays a crucial role in plant physiology as a stress hormone. As comparative effects of C2H4 released from CaC2 and SA are not thoroughly investigated particularly for production of vegetables with improved quality, therefore, a series of laboratory, pot and field studies were conducted to scrutinize the effectiveness of CaC2 dependent C2H4 with and without application of SA for seed germination, physiological, morphological, yield and quality parameters of sweet pepper. Experiments were conducted in three sections. Section I, II and III consisted of four laboratory, three wire-house/pot and two field experiments, respectively. From first experiment of section-I, polyethylene and paint were selected as the most effective materials for coating CaC2. In second experiment of section-I, it was observed that CaC2 up to 14 mg plate-1 induced early seed germination with 100% germination rate and better seedling growth parameters but application of CaC2 ˃16 mg plate-1 inhibited seed germination and seedling growth parameters of sweet pepper. Similarly, results of third experiment of section-I revealed that SA concentration ≤0.4 mM can be used to improve germination percentage and seedling vigor of sweet pepper. In last experiment of section-I, it was noted that SA alleviated injurious effects of CaC2 with ˃16 mg plate-1 on seed germination and seedling growth parameters. In section-II, data revealed that 20 mg CaC2 kg-1 soil while 0.3 mM SA can be used for maximization of sweet pepper productivity. In last pot trial, effect of CaC2 with and without SA was investigated on growth, yield and fruit quality of sweet pepper under salinity stress. It was observed that detrimental effects of excessive C2H4 from CaC2 on physiology, photosynthesis, growth and yield of sweet pepper were mitigated by the foliar application of SA under saline conditions. On the basis of preliminary trials of section I and II, two field experiments were conducted on two different locations (section-III). Results of both field experiments showed that application of CaC2 along with foliar application of SA improved photosynthetic activity by 7-77%, plant water use and carboxylation efficiency by 10-211%, antioxidant and enzyme activities by 15-53% and finally fruit yield by 5-34% with a significant increase in fertilizer use efficiency compared to that of plants without SA and CaC2 application (control). Additionally, quality parameters related to chemical composition of sweet pepper fruits were also improved by the application of CaC2 with foliar application of SA. These parameters are very much required for improvement in shelf life. In short, results confirm the synergistic role of SA and CaC2 for improving physiology, growth, yield and quality of sweet pepper. Our results suggest that application of 200 mg plant-1 polyethylene coated CaC2 with foliar application 0.1 or 0.3 mM SA is relatively more economically beneficial and effective than application of 200 mg plant-1 polyethylene coated CaC2 without foliar application of SA. Moreover, results also indicated that SA treated plants were tolerated abrupt release of C2H4 from applied CaC2 to a greater extent.

This is an abstract of thesis of Dr.   AHMED, WAZIR for complete thesis please visit http://prr.hec.gov.pk/jspui/handle/123456789//7063

Evaluating the maize productivity under different irrigation and nutrient management practices

Pakistan is water stressed country in which agriculture is major consumer of fresh water supplies. The competition among agriculture, industry and domestic use leads us to acquire alternate source for crop production. However, the quality of alternate water source may result in deterioration of soil in general, particularly crops for human and animal consumption. The objective of present study was to evaluate the use of canal, domestic and municipal wastewater along with press mud application as alternate and improved farm management practices for sustainable food production. To explore the impact of wastewater and press mud on maize, one pot and two field experiments were conducted. The irrigation sources used in the study were municipal wastewater, domestic wastewater and canal water. While the nutrient sources were press mud and inorganic fertilizers. In the pot study different combinations of water qualities and nutrient sources were studied. The results showed that wastewater had adverse effects on the emergence parameters, whereas, press mud mitigated these effects. Seedling growth was good with more plant length and dry weight with municipal wastewater along with press mud followed by the domestic wastewater with press mud. Among the field experiments in first experiment, effect of press mud application under different irrigation waters (municipal wastewater, domestic wastewater and canal water) in comparison with inorganic fertilizers on yield and quality of hybrid maize was studied. In second field experiment, productivity of hybrid maize was tested under different irrigation treatments (T1=canal water, T2=domestic wastewater, T3=municipal wastewater, T4=alternate canal-domestic-canal, T5=alternate canal-municipal-canal, T6=mixed canal & domestic and T7=mixed canal & municipal). All the agronomic traits, plant height (cm), cob diameter, number of grain rows per cob, number of grains per cob, 1000-grain weight (g), biological yield (t ha-1) and grain yield (t ha-1) gave higher values with an increase of 22-27 % in grain yield under municipal wastewater irrigation with press mud in the first experiment over both the years. In second experiment municipal wastewater was best with statistically similar or followed by mixed canal & municipal and alternate canal-municipal-canal regarding the growth and yield components and the highest yield in both the years 2012 and 2013. Municipal wastewater irrigation along with press mud in first field experiment while, municipal wastewater as such or mixed with canal water significantly gave higher seed oil content (%), seed starch content (%) and seed protein content (%) in both the years of study. Seed heavy metal (Cd, Pb, Ni, Cu and Zn) contents were found to be within the limits proposed by international food quality standards in maize under all treatments.

This is an abstract of PhD thesis of  DILDAR KHAN, RANA and taken from hec website you can view complete thesis at http://prr.hec.gov.pk/jspui/handle/123456789/7652

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

Forage productivity, silage characteristics and digestion kinetics of cereal-legumes mixture under different tillage systems and varying row and seed ratios

In many parts of world intercropping of legumes and non-legumes is considered very important practice. When legumes is grown in mixture with non- legumes they contribute well to non- legume crop for nitrogen. To investigate the forage potential and characteristics of silage of cereal-legume intercropping under various planting ratios and different tillage systems the study was conducted during spring season 2013 and 2014, which was comprised of two experiments each experiment consist of three parts Field trial, Laboratory scale silage and In situ digestion kinetics trial. Field trials were conducted at Agronomic Research Area, University of Agriculture Faisalabad, Pakistan. The tillage practices and row ratios in first experiment were minimum tillage; one ploughing with cultivator followed by planking; deep tillage; one ploughing with chisel plough + one ploughing with cultivator followed by planking; and row ratios sole sorghum, sole millet, sole sesbania, sorghum + sesbania(1:1), sorghum + sesbania(1:2), sorghum + sesbania(2:1), millet + sesbania(1:1), millet + sesbania(1:2), millet + sesbania(2:1). The tillage practices and seed ratios for second experiment were include minimum tillage; one ploughing with cultivator followed by planking; deep tillage; one ploughing with chisel plough + one ploughing with cultivator followed by planking; and seed ratios sole maize, sole cowpea, maize + cowpea (60% + 40%), maize + cowpea (70% + 30%), maize + cowpea (80% + 20%). Field trials of both experiments were laid out in randomized complete block design having split plot arrangement with three replications. In both experiments tillage practices significantly affected the growth and yield of forage. Results showed that the deep tillage practice significantly increased the emergence count, plant height, number of leaves per plant fresh and dry weight per plant, fresh forage yield and dry matter yield while it has little effect on the quality of cereal-legume mixed forage. In both experiments intercropping ratios significantly affected the growth, yield and quality of forage. In first experiment cereals sown in mixture with sesbania with different row ratios, sorghum sown alone produced significantly higher fresh forage yield and dry matter yield than all other row ratios of cereals in combination with sesbania. Minimum fresh forage yield and dry matter yield was observed in sole sesbania during both years of study. All cereal + sesbania mixture produced higher crude protein percentage, ash contents and lower crude fiber percentage than sole cereals. Land equivalent ratio (LER) was highest in sorghum + sesbania (1:1) row ratio. In second experiment maize sown in mixture with cowpea with different seed ratios, maize sown alone produced significantly higher fresh forage yield and dry matter yield than all other seed ratios of maize in combination with cowpea. Minimum fresh forage yield and dry matter yield was observed in sole cowpea during both years of study. All maize + cowpea mixture produced higher crude protein percentage, ash contents and lower crude fiber percentage than sole maize. Land equivalent ratio was highest in maize + cowpea (70% + 30%) seed ratio. Silage quality increased with increased in concentration of legumes crop in forage mixture as compared to sole cereal crop silage which resulted in an increase in dry matter (DM) and neutral detergent fiber (NDF) degradability in rumen of cannulated buffalo bulls.

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Impact of exogenous application of tea seed extract and its waste products on morphological, physiological and reproduction of plants

   Erum Rashid*, Mirza Rehan Ahmed, Shahla Rashid

(University College of Agriculture University of Sargodha, Sargodha)

A number of plant extracts are being marketed demanding to improve both yield and quality and environmentally friendly. However, these claims are rarely recognized by precise data. The growth regulatory effect of Tea Seed powder (TSP), a saponin- rich waste produce from Tea seed (Camellia sp.) oil production. To manage variability of soil and environment different strategies have been applied within the agricultural and horticultural industry, high quality and high yield crops are of main commercial and economic importance. The demands for increased yield and improved quality can be met through improvements in crop genotypes by selection, breeding, and genetic engineering and by improvement of the crop growth environment through irrigation, fertilization, and the use of plant protection products. Chemical growth regulators are also one of the tools used to improve both crop growth and quality. Commercially registered growth regulators are all phytohormones and fall into the subsequent categories: gibberellins, auxins, abscisic acid, ethylene, and cytokinins. Recently, several other hormonal compounds such as brassinosteroids, oligosaccharins, salicylates, jasmonates and polyamines have also been revealed to have growth-regulating properties.

Tea is evergreen but it is mostly inactive in winters. Mechanical harvesting is done where no cheap labor is available. Tea plant extracts have been used from centuries to combat diseases, enhanced plant production/growth by the foliar application. That showed useful effect on the plant health. Camellia sinensis belongs to Theaceae family (tea family), from which green tea is made by the use of its leaves. Plant is shrub which persists throughout the year it has two cotyledons and it is an angiosperm. Southeast Asia is said to be its natural habitat, China is considered for introducing evergreen tea plant to the rest of the world. Aqueous tea compost extract application has shown positive trend in plant nutritive quality, production and crop health. Chemically tea (Camellia sinensis) plant has plenty of nutrients and plant growth regulating constituents. More than 80 percent unsaturated fatty acids are present in tea. Camellia sinensis contain more than 4000 bioactive compounds out of which 1/3 comprise of polyphenols. Alkaloids including caffeine and the bromine, amino acids, chlorophyll, carbohydrades, proteins minerals, fluoride and trace elements. Most of the polyphenols present in tea (camellia sinensis) are the flavonoids. Catechins belong to the large plant chemical group polyphenols that has many health benefits. Tea is rich in simple polyphenol mixture i-e complex polyphenols and catechins, oolong, black and green tea is also rich in ascorbic acid (Vitamin C).

Soluble mineral nutrient, water soluble plant growth regulators and organic acid derived from tea applied to soil and foliar spray has positive impact the plant growth and plant root development at juvenile phases. There are distinct numbers of polyphenolic compounds which are present in tea plant (camellia sinensis) probably which act as chemical defensive mechanism against animals and birds that may harm the plant. Foliar application of tea compost has been reported to restore and increase beneficial micro-organisms in the soil that can be destroyed if chemical fungicide may be used. Beneficial micro-organisms help to combat disease, rose powdery mildew. Hydraulic conductance of stem, transpiration from leaves of cut flower and shelf (vase) life has inspected to be effected by the application of tea seed extract, thus its vaselife may be extended. Zeatin is a plant growth regulating hormone that enhances the plant growth, which is a constituent of extract of moringa leaves (MLE). Fe, Ca, K, ascorbate and amino acids are also present. Plant growth has been influenced in different ways by the plant growth promoters, endogenous concentration of plant growth regulators is adjusted and abiotic defense mechanism against stress is improved. Growth promoters thus applied foliar for optimum utilization. Biological activity of tea seed saponin comprise of insecticidal, anti-bacterial and biological harmone properties. Camellia sinensis has high quantity of mineral nutrients in different concentration i-e Cu and Ni. Germination, stem number and diseases like black and silver scurf in potato (solanum tuberosum) are intensively effected in positive way by tea compost foliar application, whereas has in-significant impact on yield and other diseases like scab, dry rot and early blight. Camellia sinensis seeds contain enormous quantity on phenolic compounds. The basic role in food quality including flavor, appearance and health promoting properties. Genetic makeup, agronomic and environmental factors are the reason for phenolic stability. a number of crops detoxification of polyamines and ammonia production, and increase in antioxidant production is observed with the application of cytokinins which is an active constituent of tea seed. There are number of growth enhancer mixture of variety of compounds, which have multiple functions in terms of simultaneously improving nutrients availability, providing insecticide and fungicidal effect, and furthermore chances of hormonal effects.

* erumrashid91@gmail.com