Control methods of eggplant yellow leaves in greenhouse in deep winter and low temperature period

In the low temperature period of deep winter, the heart leaves of eggplant are easy to turn yellow, which leads to the decrease of photosynthetic efficiency and the yield is affected. Symptoms: from the bottom of eggplant leaves between the veins began to turn yellow, showing an irregular cluster of yellow spots, mixed with brown sunken spots, such as more serious, resulting in the leaves become paste and dry, gradually spread upward, the top new leaves become light, appear to fall off.

Yellow leaves of eggplant

According to the analysis of greenhouse situation, the root cause of yellow leaves of eggplant is that the ground temperature is too low, especially when the local temperature is lower than 10 ℃, long eggplant is prone to low temperature obstacle, which leads to weakening of root activity, and the absorption of mineral nutrients can not meet the growth needs of eggplant, so it is easy to cause yellowing of heart leaves caused by element deficiency.

Many vegetable farmers spray foliar fertilizer containing zinc and iron to supplement trace elements and promote the leaf color to turn green, but this method is not a permanent cure. If it is fundamentally improved, it is necessary to promote the absorption of trace elements by eggplant roots to alleviate the yellowing of heart leaves.

When operating, adhere to the principle: to maintain the root system and improve the absorption function of eggplant root system.

Specific methods:

1. When the weather is fine, a heavy water should be watered once, and the 25-30cm soil layer that seeps into the soil should be watered. At the same time, water-soluble fertilizers with full nutrient content should be applied along with the water to supplement all kinds of nutrients needed for eggplant. After that, small water should be watered frequently.

Second, during the growing period of eggplant, the soil should be avoided to be too dry, so as to avoid damage to eggplant roots caused by sudden watering.

Third, because the price of long eggplant is high in the early days of the Spring Festival, many vegetable farmers leave as much fruit as possible, so that the supply of nutrients is insufficient and the leaves are easy to yellow. in addition, some vegetable farmers only pay attention to promoting fruit and increasing the use of potash fertilizer, while neglecting to supplement nitrogen fertilizer.

The peak fruiting period of long eggplant is the parallel period of vegetative growth and reproductive growth, both of which need sufficient nutrients. If only potassium is supplemented, it is bound to cause nutrient deficiency. Therefore, it is suggested that vegetable farmers should pay attention to nitrogen fertilizer while supplying potassium fertilizer. 15:10:15 irrigation fertilizer can be used.

In addition, many vegetable farmers realize that eggplant is undernourished and want to improve the situation by using biological fertilizer, which is obviously not symptomatic. The function of biological bacterial fertilizer is to improve the soil, to promote the absorption of soil nutrients by optimizing the soil structure, but can not directly supply a large amount of nitrogen, phosphorus, potassium and other nutrient elements, but by increasing the temperature in the greenhouse, especially at night, it plays a role in promoting root and rooting.