Key Technical Points for Boosting High Yield in the Late Growth Stage of Peanuts

1. Timely drainage and irrigation. During the full-pod maturity stage, the plant's water consumption drops sharply and the root system's water-absorbing capacity weakens. If there is excessive autumn rain and poor drainage at this time, it will cause root rot, withered and declining stems and branches, and the occurrence of pod rot disease. Therefore, attention should be paid to promptly draining away accumulated water. In addition, although the plant's water consumption is low during this period, if drought occurs, the root system is prone to decline, causing the top leaves to drop, and the stems and branches will then decline as well, resulting in reduced yield. Therefore, timely irrigation is still necessary during drought.

2. Control plant growth and increase pod set. The pod-setting stage is the period of most vigorous peanut growth and also the peak period of fertilizer and water demand; insufficient water and fertilizer will affect the plant's growth process and pod plumpness. However, good soil fertility and heavy fertilizer and water application during the pegging stage can also cause excessive vegetative growth and premature row closure, resulting in a closed canopy in the field, tall-hanging pegs with many pegs failing to set and many pods failing to fill. Therefore, 30 to 50 days after the start of flowering, when the main stem reaches 35 to 40 cm in height, the first pair of lateral branches has 8 to 10 nodes, and the average length exceeds 10 cm, a chemical regulator should be sprayed on the leaves in a timely manner.

3. Foliar fertilizer application. After the pod-setting stage, the peanut root system's absorption capacity weakens, and the main nutrients in the stems and leaves cannot meet expenditure; the leaves at the base of the stems and branches gradually drop, and by harvest time each stem and branch has only 4 to 6 top leaves, which are the basis for maintaining the vitality of the whole plant and carrying out photosynthesis. In order to enhance leaf vitality and prolong the functional period, foliar fertilizer should be sprayed starting from the late podding stage, once every 7 to 10 days, for a total of 2 to 3 sprays. Each time, use 500 grams of urea and 100 grams of monopotassium phosphate per mu, add 50 kg of water to dilute, and spray.

4. Disease and pest control. The main diseases and pests include leaf spot, rust, cotton bollworm, aphids, and white grubs. For leaf spot, spray once every 10 to 15 days according to the severity of the disease, for 3 to 4 consecutive sprays; for rust, begin applying the pesticide when diseased plants are seen, spraying once every 10 to 15 days, for 2 to 3 consecutive sprays. Commonly used pesticides include 70% thiophanate-methyl wettable powder at 1500 times dilution, 75% chlorothalonil wettable powder at 600 times dilution, and 20% copper green emulsion and 30% Ludebao emulsion at 500 to 600 times dilution. Pests should be controlled early.

5. Timely harvest. Determining the suitable harvest time for peanuts is especially important. Generally, whether peanuts have reached the harvest period can be judged from the following three aspects: First, look at the growth period. The growth period of common peanut varieties is about 125 days. Second, look at the temperature. When the average day and night temperature is below 12°C, the plant basically stops growing, and it can be harvested at this time. Third, look at the plant. Under normal circumstances, when peanuts enter the late podding stage, most of the nutrients in the plant have already been transported to the pods, and the plant shows signs of aging, that is, the top stops growing, the upper leaves turn yellow, and the leaves at the base and middle drop. At this time, most pods have plump kernels and can be harvested.

Jia Youjiang, Agricultural Bureau of Juancheng County, Shandong Province