"six points for attention" of topdressing fruit trees outside their roots

1. According to the purpose and period of topdressing outside the root, choose the type and appropriate concentration of fertilizer, too thick and easy to burn the leaves, causing fertilizer damage, too thin fertilizer effect is not obvious.

2. The external conditions of topdressing outside the root are relatively strict, such as air humidity, precipitation, temperature, ground coverage, etc. When the conditions are not suitable, the topdressing effect is not high. The relative humidity of the air when spraying fertilizer is 40%~50%; if it rains within 48 hours after spraying fertilizer, it must be sprayed again; dry and hot weather should not be carried out, and it should be sprayed at a time when the temperature is low and the evaporation is small. The appropriate time is before 9 a.m. or after 4 p.m. to maintain the moist state of fertilizer solution, prolong the absorption time and increase the absorption capacity of leaves; The topdressing outside the root can be carried out only when the ground coverage reaches more than 60%, and special needs can be carried out at any time.

3, a variety of fertilizers, pesticides mixed use, special attention should be paid to make sure that the mixture can not produce precipitation.

4. Strictly control the concentration and spraying amount of the solution to prevent burning leaves or insufficient dosage from achieving the expected effect.

5, to focus on the new leaves, leaf back spraying, but the leaves are sprayed on both sides, so that mineral nutrients can enter the leaves as soon as possible, improve fertilizer efficiency.

6. The amount of topdressing outside the root is small, which can only be used as an auxiliary measure, and the root fertilization should still be carried out on time. Qiu Rongxiang