For high peanut yields, manage these four key points well in the late stage
The late growth stage of peanuts runs from when 50% of the plants show filled pods to when most pods mature and are harvested. The growth characteristics of this period are: vegetative growth gradually declines and stops, the pods gradually fill out and become plump, and the increase in pod weight generally accounts for 500%-70% of the total pod weight, making it the main period for pod yield formation. Field management technical measures for this period...
The late growth stage of peanuts runs from when 50% of the plants show filled pods to when most pods mature and are harvested. The growth characteristics of this period are: vegetative growth gradually declines and stops, the pods gradually fill out and become plump, and the increase in pod weight generally accounts for 500%-70% of the total pod weight, making it the main period for pod yield formation. The field management technical measures for this period are:
1. Foliar fertilization to protect the top leaves. In the late growth stage of peanuts, the uptake of the three key elements nitrogen, phosphorus and potassium accounts for 6.3%, 5.3% and 0.75% of the total uptake over the whole growth period respectively. Although the nutrients peanuts need during this period are small in amount, they greatly affect yield formation and improve pod plumpness. The root absorption capacity of peanuts weakens in the late stage. To make up for insufficient fertilizer supply, starting from the late podding stage, spray the leaves with a 1%-2% urea and 2%-3% superphosphate aqueous solution 2-3 times every 7-10 days, using 50 kg per mu each time, to prolong the functional period of the top leaves and increase the plump pod rate.
2. Water during drought to increase filled pods. In the late growth stage of peanuts, the suitable soil moisture is 50%-60% of the maximum field water-holding capacity. If drought occurs during this period, the root system easily declines, and this quickly causes the top leaves to drop and the stems and branches to wither, reducing the filled pod rate and leading to yield loss. Therefore, when soil moisture falls below 40%, water immediately to protect the roots and leaves and increase the filled pod rate. When watering, use small furrow irrigation or sprinkler irrigation, and never use large-scale flood irrigation.
3. Drain waterlogging promptly to prevent pod rot. In the late growth stage of peanuts, if there is excessive autumn rain and poor drainage, it easily causes root rot, and in severe cases the pods may rot or sprout. Therefore, when there is too much rain in the late growth stage, dredge ditches promptly and remove standing water and waterlogging to ensure high quality and high yield.
4. Control leaf spot disease and white grubs. The main disease in the late growth stage of peanuts is leaf spot disease, with its peak incidence 20-30 days before peanut harvest, and it is more severe under high temperature and high humidity or continuous rainy weather. You can use 75% chlorothalonil wettable powder at 600 times dilution or 70% thiophanate-methyl wettable powder at 1000 times dilution for spray control, spraying once every 10-15 days for 2-3 consecutive sprays. For fields with severe white grub infestation, use 50% phoxim emulsifiable concentrate at 1500 times dilution to drench the mounds, applying 50 g of solution per hole; watering after drenching gives better control. In addition, special attention should be paid to the fact that peanuts are an oil crop, so when controlling white grubs, it is strictly forbidden to use systemic highly toxic pesticides such as 3911, methamidophos and 1605, so as not to affect human health.