soya bean

Soybean seed is of bold size and 30-35kg per acre is recommended for the appropriate soybean plant population. Seed treatment is very important to avoid seed and soil-borne diseases. Seed treatment with systemic fungicides kills the pathogen present in the seed (seed-borne) while it also protects the seed from pathogens present in the soil (soil-borne). Therefore, the following fungicides are recommended for seed treatment.

1. Topsin-M (Thiophanate methyl @ 2g/kg of seed)
2. Mancozeb 2g/kg of seed
3. Carbendazem 2g/kg of seed
4. Thiram 2g/kg of seed

Sowing Time:

The proper sowing time provides an appropriate growing period, temperature, and sunshine hours for good growth and development of crops. The sowing date is important mainly because of the photoperiod sensitivity of the crop. Late sowing shortens the vegetative phase of the crop, leading it to initiate flowering when day length decreases to a critical value. Whereas early sowing severely affects emergence resulting in yield loss. Autumn (Kharif) sowing of Soybean is successful in Punjab because it avails Monsoon rains and mild temperature for the onset of the reproductive phase and subsequent grain filling stage. The best sowing of the Soybean crops in different zones of Punjab is from 15th July to 20th August for optimum grain production. However, in the case of Spring sowing Soybean, vegetative growth thrives well. But At the seed development stage, the temperature rises and severely affects the seed growth. Resultantly, the shriveled seed is produced with low nutrients and poor germinability. Therefore, spring sowing of Soybean is not recommended in Punjab. In rainfed areas, sowing should be done after good rainfall in mid-July to onwards.

Selection Of Soil:

Soybean grows well on well aerated, medium to heavy loam soils with good drainage having pH between 6.0 and 7.5 Sodic and saline soils inhibit the germination of seeds. Water logging is also injurious to the crop. Ion rainfed areas, soil with a high level of moisture holding capacity (Clay Loams) are most productive. Soybean is better adapted to soil types with a lower pH than other legume crops, but a pH lower than 5 obstructs nitrogen fixation. Compacted soils should also be avoided.

Land Preparation:

The well-pulverized soil is very important for proper root growth and establishment to ensure the uptake of nutrients by plants. The seedbed must be properly leveled, uniform, fine-textured, and evenly moistened throughout the seed depth. For a well-prepared soil, 1 revert cultivation through rotavator to crush previous crop residues and large clods of minimum 2 ploughings followed by 2 planking should be applied. To control weeds and maintain uniform moisture, double Rauni irrigation may be applied if ample water is available. After every 3 years, deep plowing through the Chisel plow and LASER leveling should be applied to breaking the hard pan and leveling the land.

Soybean Varieties:

Presently, a limited number of soybean varieties are available and developed by research institutes in Pakistan given in the Table below.

Sowing Method:

Different sowing methods for successful soybean cultivation may be adopted in Punjab.

Line Sowing with Drill:

The best method for soybean cultivation is line sowing with seed drills. This method is cost-effective with less labor engagement and best fit for intercultural operation and mechanization of mass-scale soybean cultivation. In drill sowing of soybean, Row x Row distance of 1-1.5 feet (30-45cm) should be maintained. Line sowing must be done in well moist soil (Tar-water) and the seed depth should not be more than 1.5-2 inches for proper emergence.

Ridge sowing:

In case of non-availability of Soybean seed drill and unfavorable climate conditions, soybean may be cultivated on ridges. In this sowing method, broadcast the soybean seed after land preparation and make small ridges at an R x R distance of 1.5 feet. Then irrigate the field lightly.

Bed sowing:

In the maize-grown areas (Sahiwal and Okara) bed sowing may also be practiced. In this sowing method, seed cost is reduced due to less seed requirement, and good seed germination is assured however, high labor charges increase sowing cost. In bed sowing, make 1.5 feet broad beds and sow the seeds on both edges of each bed keeping plant to plant distance of 2-3 inches. The seed must not be planted deeper than 1.5 inches on both sides of the bed. Then irrigate the field. This method ensures good germination under high temperatures and to some extent in rainy days too.

Intercropping of Soybean:

Soybean can be successfully grown in citrus orchards to enhance the fertility of soils with an extra-economic return. However, studies on intercropping of soybean with corn, sorghum, sugarcane, and sunflower are in progress at Oilseeds Research Institute, Faisalabad. After successful experimentation and valuable results, the intercropping of soybean in the above-mentioned crops will be recommended.

• Alternaria Leaf Spot:

Causal agent:  Alternaira spp. (fungus)

Symptoms:

Alternaria leaf spot occasionally appears in seedlings but generally attacks leaves and pods of the plants approaching maturity. Diseased lesions are round or restricted by a major vein or merge with another lesion Some have brown concentric rings with a well-defined border. The lesions expand and may combine to larger dead areas on the leaves. Infected leaves eventually dry out and fall.

Control:

Seet treatment with systematic fungicide. Nativo (Tebuconazole +Trifloxystrobin) = 1g/kg of seed. Or Topsin - M (Thiophanate methyl) = 2g/kg of seed Foliar spray of fungicide when disease incidence occurs. Nativo (Tebuconazole +Trifloxystrobin) = 1g/kg of 1g/liter of water. Topsin - M (Thiophanate methyl) = 2g/liter of water).

• Anthracnose:

Causal agent: Collectotrichum truncatum (fungus)

Symptoms :  

The most common symptoms are seen late in the cropping season as the plants approch maturity. Irregular brown spots develop in a random pattern on stems and pods. The infected areas are covered with tiny black spines (setae). Brown cankers can appear on petioles and cause defoliation. Infection of pods results in few or small seeds per pod. Seeds infected by anthracnose may not germinate.                                                                      

Control:

Seed treatment with systematic fungicide. Nativo (Tebuconazole + Triflxystrobin) = 1g/kg of seed. Or Topsin-M (Thiophanate methyl) = 2g/kg of seed. Foliar spray of fungcide when disease incidence occurs. Nativo (Tebuconazole + Trifloxystrobin) = 1g/liter of water. Or Topsin-M (Thiophanate methyl) = 2g/liter of water.           

• Charcoal Rot:

Causal agent: Macrophomina phaseolina (fungus))                                                                            

Symptoms                                                  

Infected seedlings may show reddish-brown discoloration. The discoloration area turns dark brown to black and infected seedlings may die under hot & dry conditions. Infected plants produce slightly smaller leaflets than healthy plants and have reduced vigor. As the disease advances, leaflets become yellow, then wilt and turn brown. The brown leaves remain attached to the petioles. A light gray of sliver discoloration will be visible in the taproot and lower stem when plants are split open. Black specs (microsclerotia) will be visible in this tissue of the stem and tap root. Outer tissues will have black, dusty microsclerotia. Plants in the driest parts of the field will typically show symptoms first.

Control:                                                        

Rotation to non-host crops such as wheat for 1 or 2 years in fields with a history of Charcoal Rot. Corn, sunflowers, and other crops are hosts; research has shown that there are strains of the fungus that have host preferences. For instance, some strains prefer soybean while others prefer corn or sunflowers. Therefore,            rotation with any other crop can be beneficial to control Charcoal rot.

• Soybean Mosaic Virus:

Causal agent: Soybean mosaic virus (SMV)                          

Symptoms:                                     

Trifoliate leaves will have a mosaic of light and dark green areas that may become blistered or raised with time. Leaves may appear distorted, generally with the leaf margins curling downward. Seed from infected plants can be mottled black or brown depending on hilum color. Not all infected plants produce mottled seed and seed mottling does not indicate that the virus is present in the seed.                                                     

Control:                                

Management of SMV is based on the use of virus-free seeds and avoiding late planting of soybean to minimize aphid transmission. Rogue out infected plants when found. Use of resistant varieties. Control the insect vector with a suitable insecticide. Use micro-nutrients especially amino acids to enhance immunity.            

• Phytophthora Root:                                                                     

Causal agent: Phytophthora sojae (Fungus)                                                                          

Symptoms:                                                                              

Plant may be affected anytime during growing season from the time of planting till harvest. Stems of infected seedlings are soft and water soaked. Secondary roots are rooted and leaves turn yellow and brown. Infected seedlings are wilted and stunted. Symptoms of the seedling phase resemble the symptoms of many other seedling diseases. Infected Plants Appear alone or m patches. Chocolate brown lesions are formed leading to stem rot.                                       

Control:                                                                    

Increase the drainage of the field to reduce the likelihood of saturated soil. Crop rotation and tillage may be of some benefit. Treat the seed with any good fungicidal compounds such as Mandipropomide@2.5ml/Liter or Metalaxyl+Chlorothianil@2.5ml/Liter or Metalaxyl+Mancozeb@2.5g/Liter can be beneficial.                                                                                              

Whitefly:

Mode Of Damage:

Nymphs and adults of whitefly such cell sap from phloem tissue while the remaining underside of the leaves excretes a covering of sticky honeydew. This sugary and sticky material acts as an excellent medium for the development of fungus; sooty mold. Sooty mold gives a black appearance to the leaves and hampers the process of photosynthesis. Due to the depletion of nutrients, plants become stunted; leaves turn yellowish-brown and fall off. Whitefly injects toxic saliva into the plants and alters the physiological process which results in plant disorder. It also acts vector for yellow mosaic virus disease in soybeans.

Economic threshold level:

Control measures should be adopted when the population of whitefly reaches 5 nymphs or adults per leaf on Soybean.

Chemical Control:

• Spirotetramate 240SC (125ml) + Biopower (250ml) per acre.
• Pyriproxyfen 10.8EC at the dose rate of 400ml per acre.

Soybean Aphid:

Mode Of Damage:

Winged Soybean aphids colonize in the early season and produce wingless females through parthenogenesis (reproduction without fertilization) on young and developing leaves. Aphid suck plant sap which results in curling the leaves downward and stunting the growth of plants. When the population grows, the attack can be witnessed up to the middle of the plant feeding underside of the leaves. This can cause yield losses of up to 50%. It can transmit soybean mosaic virus if it is infected with it, causing significant yield losses when plants are also infected with other viruses. At the end, of the cropping season, it is transformed into a winged form and leaves the crop.

Economic threshold level:

Control measures should be adopted when the Soybean aphid population reaches 250 per plant, with more than 80% of the plants infested while the insect population is still increasing.

Chemical Control:

• Carbosulfan 20EC at the dose per rate of 400ml per acre.
• Pymetrozine 50WG at the dose rate of 80g per acre.

Soybean Lopper:

Mode Of Damage:

Only the Larval Stage of Soybean looper is responsible for significant damage in Soybean. Eggs are laid underside of the leaves and newly emerged larvae are unable to feed the upper cuticle. So, they feed the underside of the leaves and a transparent appearance is expressed on the upper side of the leaves. Old larval instar causes irregular holes in the leaves by feeding them.

Economic threshold level:

When defoliation reaches 40% at the pre-bloom stage, or 20% during bloom and pod-fill, or 35% from pod-fill to harvest stage of Soybean, then control measures should be adopted. In other words, when the insect population becomes 4 larvae per one-meter row of plants (4 larvae/10 plants) at the following stage or 3 larvae per meter row (3 larvae/10plants) at the pod initiation stage, the control measures should be adopted.

Chemical Control:

• Lambda-cyhalothrin 2.5EC at the dose rate of 250ml per acre.
• Cypermethrin 10EC at the dose rate of 200ml per acre.

Soybean Stem Fly:

Mode Of Damage:

Maggots bore into veins and reach stems where these maggots eat cortical layers. As a result, zig-zag tunnels are formed. Plants face wilting or die in severe infestation of stem flies. The adults feed on the fluid that oozes out from punctures made on leaves by ovipositor which appear as white spots on leaves. An early-stage infestation causes about a 30% reduction in yield.

Economic threshold level:

Control measures should be adopted when 10-15% of plants are infested.

Chemical Control:

• Thiamethoxam (200 g.a.i.) +

Chlorantraniliprole (100 g.a.i.) 300SC at the dose rate of 80ml per acre.

• Chlorantraniliprole 20SC at the dose rate of 50ml per acre.

Army Worm:

Mode Of Damage:

Caterpillars are the most damaging stage of armyworms. Young larvae are gregarious in nature and nibble the leaves from a lower surface. Mature larvae make irregular holes and only veins are left in leaves. It is held responsible for about 30-50% yield losses.

Economic threshold level:

Control measures should be adopted when one armyworm is spotted in the field as it grows very rapidly, and it needs to be controlled within a very short duration of time.

Chemical Control:

• Emamectin Benzoate 1.9EC at the dose rate of 200ml per acre.
• Lufenuron 5EC at the dose rate of 200ml per acre.

Soybean Pod Borer:

Mode Of Damage:

Larvae feed on leaves and tender plant parts. The larvae bore pods and feed on grains during the reproductive stage of Soybean.

Economic threshold level:

Control measures should be adopted when 5 larvae per meter now (5 larvae/10plants) at the pod initiation stage are found.

Chemical Control:

• Emamectin Benzoate 1.9EC at the rate of 200ml per acre.
• Flubendiamide 480SC at the dose rate of 50ml per acre.

Pre-emergence weedicides:

In case of line sowing, Pendimethalin @ 100ml/120-liter water or S-Metolachlor @ 800ml/120-liter water for one acre must be applied just after sowing in wattar condition as pre-emergence weedicides to control broad leaves weeds in Soybean.

Post-emergence weedicides:

Quizalofop-P-Ethyl 15% EC @ 250-300ml per acre or Haloxyfop-R-Methyl @ 300-350ml per acre may be applied to control narrow leaves weeds in Soybean. Always use special herbicide nozzle to spray herbicides.

Hoeing:

First weed eradication must be done before 1st irrigation (Dry Hoeing) and 2nd weed eradication must be done after 1st irrigation at wattar condition. However, some herbicides are also recommended for both pre-emergence and post-emergence application.

Water is important for the translocation of nutrients from the leaf and stem to the seeds. Soybean is sensitive to water shortage, especially at the pod formation stage. Substantial pre-sowing irrigation which wets the soil from 60 to 100cm is recommended and moderately large amounts at longer intervals are preferred for frequent small applications. Adequate moisture during the flowering stage will ensure fertilization of flowers to produce maximum pods. Shortage of water during the grain-filling stage can reduce yield by as much as 30%. For irrigated areas of Punjab, the irrigation schedule is given in the table below which can be altered considering rainfall and environmental temperature.

Low rainfall Barani areas require mandatory supplemental irrigation facilities to provide irrigation at a critical stages of grain filling. If water stress occurs at this stage, it may lead to very poor seed formation reducing seed yield drastically.

Nutritional Requirement:

In time application of balanced regularizes plant nutrient uptake and ultimately enhances productivity. The nutritional requirements of soybean are moderately high in comparison with other gains. Soybean consumes more phosphorus, potassium, magnesium, and calcium than maize crops do. The Soybean plant has a strong tap-root system and is able to use nutrients in the subsoil very effectively. Seed inoculation and rotation with crops applied to high fertilizer doses, lower the extra requirement of nutrients to be added to the soil. Soybean responds well to soil reserves that have built up over a long period through fertilization of previous crops in rotation. However, in poor nutrients soils, fertilizer must be applied prior to sowing. Fertilizers can be broadcasted and plowed into the root zone.

Macro elements:

Nitrogen (N):

Soybean is a leguminous crop. Its nitrogen requirement is accomplished from the action of nitrogen fixation in the root nodules, but care must be taken that the seeds are inoculated with the correct nitrogen-fixing bacterium, Bradyrhizobium japonicum, before sowing. This enables plants not only to fix nitrogen to meet their own requirements but also to carry over 30 to 50kg of available nitrogen to the subsequent crop. However, in high pH soils of the Punjab having a hot climate, the nodule formation is very less or delayed in the early growth phase causing slight yellowing of leaves so, 23kg nitrogen (one bag of urea) per acre with the first irrigation is recommended in the soils having normal nitrogen level in such climatic conditions.

Phosphorous (P):

Soybean responds very well to phosphorous and continues to absorb it right up to the stage when the beans reach their full size. The phosphorous requirement of soybean is reduced when soybean is planted after well-fertilized crops. Yield will be low if available phosphorous is less than 30kg/ha. Very high soil phosphate values may depress seed protein and oil content or induce zinc and iron deficiencies. In normal soils, 23kg Phosphorous (1 bag of DAP) per acre can be applied at the time of seedbed preparation.

Potassium (K):

Soybean requires an ample amount of potassium during vegetative growth, with the highest concentration in the stems and leaves. A similar level occurs in the pods and the potassium content of the seeds is initially higher than at maturity. Potassium must therefore be more easily accessible to plants during rapid growth than in seed formation. The soil analysis will help in determining the amount of fertilizer required for obtaining a better yield. In normal soils, 25kg Potassium (1 bag of SOP) per acre can be applied at the time of seedbed preparation

Intercultural Operations:

The appropriate plant population of any crop in the field is very important for the proper growth and development of that crop to accomplish good production. Appropriate plant production can be achieved through maintaining proper plant-to-plant distance. For this purpose, sowing can be done by Numatics drill, or manual thinning is required. At four leaves stage before  1st irrigation, unhealthy plants must be removed maintaining a Plant x Plant distance of 2-3 inches. The standard plant population for soybean is 350,000 to 375,000 plants per hectare.

Harvesting & Threshing:

A delay in the harvesting of soybean may result in serious loss due to shattering. Harvesting should commence when most of the leaves have been dropped and the moisture content of the seed has lowered below 15%. This can be done through moisture testing. Otherwise, an experienced person can detect maturity by the color of the pods. When soybean is ready for harvesting, pods will turn brown and shatter easily and the grain will not yet be dry enough to break.

Manual harvesting and threshing are not suitable for the mass-scale cultivation of soybean. The recommended harvesting method is to use a combine harvester calibrated for Soybean of Peas. Automated combines with a reasonable capacity should be able to harvest 14 hectares a day. While harvesting soybean with a Combine harvester, a slow drum speed of 450-500 revolutions per minute is required. The concaves must be set wider than for wheat and a slow ground speed (approximately 6km/h) must be used. The faster the drum speed, the more splits of grains will occur. To further minimize losses, the Combine Header must be adjusted as low as possible. The Combine harvester must cut the plants as close to the soil surface as possible to capture all the pods near the soil. The maturity period is fairly short and the availability of the harvesting machinery is therefore crucial, especially when unfavorable weather conditions are expected during the harvesting period.

Post-Harvest Care and Storage:

Soybean can be stored for a long period without fumigation. Owning to the inherent growth inhibitor in raw soybean, insects are not inclined to attack them. Care must be taken to ensure that moisture does not converge, because it may lead to combustion. Air movement through the grain volume is useful to about 8-10% moisture content in cool and dry places. Exposure to high temperatures during hot summer will adversely affect seed germination ability for the stock store for seed purposes. Maintenance of more than 80% germination is necessary for seed stock. Cool storage at 18’C will ensure proper germination during May to July period.

Proposed Cropping Pattern:

Considering cropping patterns in different agro-climatic zones of the Punjab soybean may fit in following cropping patterns.

1. Barani areas with supplemental irrigation:

2. Central Punjab

        (Soybean – Wheat – Soybean)

        (Spring Maize – Soybean – Wheat)

        Wheat-Sorghum/Millet – Fallow – Soybean – Wheat

1. Citrus orchards in Central Punjab

     (Inter-cropping of Soybean in young Citrus orchards instead

      Of Barseem)