Weather Based Crop
Management Plan for Soybean
Due to uneven arrival of rains across major soybean growing regions, the planting of the crop has also been staggered. The crop in some regions of MP and Maharashtra has been planted timely where as remaining areas in these states as well as in Rajasthan the crop was covered subsequently. It is estimated that slightly above 8 million hectares of soybean has been planted by the third week of July. The recommendations for farmers are as follows:
1. The
planting
of soybean after 20th July is not recommended as it is not
productive as well as profitable.Under such circumstances, it is recommended that the farmers may go for planting of early maturing catch crops (contingency crops) such as mungbean, urdbean, cowpea, maize or nizer.
2. In case of prolonged water deficit (drought) conditions during early vegetative growth stages of soybean, following measures are recommended :-
a. Make a provision of conservation furrows after 3 or 6 rows of soybean
b. Hand hoeing or bullock drawn hoeing (Dora or Kulpa) should be taken up to create soil mulch which will provide weed control as well as saving of soil moisture by reducing the evaporation losses for the crop.
c. For 15 to 20 days old crop, use of POE herbicides like imazethapyr and quizalofop ethyl if necessary is recommended.
3. In case the crop is suffering from severe water stress, exhibiting dropping of leaves a life saving irrigation preferably by Sprinkler may be given.
Advisories for pest management in Soybean
a). For crop sown during mid June: One month old crop is likely to face infestation of defoliating caterpillars like semiloopers, Spodoptera litura etc. If the caterpillars are in early instars and RH is more than 75 % then spray the crop with Beauveria bassiana or Bacillus thuringiensis @ 1.0 kg/ha Remove gregariously feeding larvae of Spodoptera manually and destroy them. Alternatively, spray Chlorpyrifos 20 EC @ 1.5 l/ha or Quinalphos 25 EC @ 1.5 l/ha or Endosulfan 35 EC @ 1.5 l/ha with atleast 500 lit of water per ha.
b). For crop sown during end of June to Mid July: The crop is in early stage and is like to be infested with stem fly, and wherever soil moisture is high blue beetle incidence is likely to be more. Spray the crop with Thiamethoxam 25 WG @ 100 g/ha. For preventing the crop from damage due to defoliating larvae, spray Rynaxypyr 20 SC @ 100 ml/ha.
c). Install bird perches (10-12 per acre) to facilitate predatory birds.
d). Specific pheromone traps (8-10 per ha) should also be placed to monitor incidence of Spodoptera litura and Helicoverpa armigera. Based on adult catches, spray of HaNPV or SlNPV @ 250 LE/ha should be done.
e). Due to exposure to strong sunshine for 4-5 days after continuous rains, the chances of occurrence of Collar rot become very high. If the symptoms of collar rot are visible, the infected seedling should be rouged out. This will help in reducing the inoculum and secondary infection to the seedlings. Hand hoeing or bullock drawn hoeing (Dora or Kulpa) should be taken up under such conditions which will provide aeration to the soil and reduce the inoculum of soil borne pathogens.
f). There are chances of occurrence of fungal leaf spots which appear in about 25-35 days old crop. If symptoms of fungal leaf spot appear on the crop, depending upon intensity of the disease, a spray of fungicide (Carbendazim @ 0.1%) may be taken up and spray should be repeated after 10 days to check the foliar leaf spots.
g). During the dry spells, with the increase in white fly population, attack of Yellow mosaic virus (YMV) disease may be encountered. At initiation the diseased plants shall be rouged out and destroyed and crop be sprayed with thiamethaxom 25 WG @ 100 g/ha to contain further spread.