Key Technical Points for Mid-to-Late Stage Soybean Management: Topdressing, Drought Resistance, and Pest and Disease Control

     At present, soybean growth has entered the pod-filling and maturation stage, which is mainly the reproductive growth period. It requires more fertilizer and water, and it is also a period of high incidence of pests and diseases. Therefore, the following points should be done well in field management: 

Soybean Management

     1. Apply flower and pod fertilizer as appropriate. From flowering to the pod-filling stage is the peak period of fertilizer demand. For plots with insufficient soil fertility where soybeans show signs of fertilizer deficiency, topdressing should be done promptly, applying 15-20 kg of diammonium phosphate per mu, which has an obvious yield-increasing effect. 

     2. Rational chemical regulation. If there is a tendency toward excessive vegetative growth, at the early flowering stage use 40-50 g of 15% paclobutrazol per mu plus 50 kg of water for foliar spraying, or use 15 ml of 25% mepiquat chloride aqueous solution mixed with 50 kg of water for spraying. If excessive growth still occurs at the full flowering stage, a second growth control treatment can be carried out. 

     3. Drought resistance and waterlogging prevention. From the early flowering stage to the pod-setting and pod-filling stage of soybean, irrigation should be done promptly in case of drought, and drainage should be attended to in case of waterlogging to avoid aggravating disease. 

     4. Spray foliar fertilizer. In addition to nitrogen, phosphorus, and potassium, boron, zinc, and molybdenum are also indispensable for soybean. Therefore, from the flowering to pod-filling stage of soybean, spray a multi-element compound nutrient solution that has the effect of increasing pods, increasing seeds, and increasing yield. The method is as follows: per mu, use 100 g of potassium dihydrogen phosphate, 50 g of zinc phosphate, 50 g of borax (first dissolve it in hot water), and 25 g of ammonium molybdate, stir thoroughly to prepare the solution, add 50 kg of water, and spray evenly on both the front and back sides of soybean leaves, spraying 2~3 times consecutively. 

     5. Control pests and diseases. 

    The main soybean insect pests to control: 1. For soybean pod borer, spray with 2.5% deltamethrin emulsifiable concentrate at 1500-2000 times dilution; 2. For clanis bilineata, spray with 20% fenvalerate emulsifiable concentrate at 2500-3000 times dilution; 3. For soybean pod borer (Etiella zinckenella), spray with 50% fenitrothion emulsifiable concentrate at 1000-0500 times dilution. 

    The main soybean diseases to control: frogeye leaf spot, spray with 70% thiophanate-methyl wettable powder at 500-600 times dilution or 50% thiram wettable powder at 500 times dilution.