Fertilizer solution should be humidified. There is a layer of stratum corneum on the leaves of fruit trees. It is difficult for the solution to penetrate. You can add an appropriate amount of humectant (neutral soap, good quality detergent, etc.) to the foliar fertilizer solution to improve The effect of spraying fertilizer on foliage.
Choose a suitable spraying time. Be careful not to spray fertilizer at high temperature. Spraying can be done all day in a cloudy day without wind; spraying should be done before 10 am and after 5 pm on sunny days.
There must be sufficient spraying amount The amount of foliar fertilizer solution absorbed by the fruit tree is proportional to the spraying amount. The appropriate spraying amount is that the fertilizer solution reaches the state of dripping on the leaves.
The concentration should be as high as possible, and the concentration of foliar fertilizer should be increased under the premise of no fertilizer damage. This will not only meet the nutrient requirements of fruit trees, but the higher the concentration, the faster it will enter the leaves. At the same time, the appropriate concentration should be adopted according to the weather and the growth of fruit trees, generally urea 0.3%-0.5%, superphosphate 0.5%-1.2%, potassium dihydrogen phosphate 0.2%-0.4%, ternary compound fertilizer 0.4%-0.5%, plant ash 1.5%-2%, the concentration of borax, zinc sulfate, ferric citrate, magnesium sulfate, etc. in the trace elements is 0.08%-0.15%.
Focus on spraying on the underside of leaves. Nutrients are absorbed into the fruit tree through the leaf stomata. The leaf stomata are mainly on the underside of the leaf. Therefore, when spraying fertilizer on the leaf surface, spray the underside of the leaf. The nozzle should be upward and the fog should be fine to facilitate the fertilizer Penetration and absorption. At the same time, the amount of spraying should not be too large, and it is advisable that the leaves do not drip, to prevent the accumulation of fertilizer and the tip of the fertilizer to burn the tip.
The symptomatic spraying of fertilizers depends on the growth of the fruit trees and spraying foliar fertilizers. If the fruit tree grows weakly, the branches and leaves are slowly elongating, and the leaves are yellow or light yellow, this indicates that the fruit tree is lacking in nitrogen and iron. Nitrogen fertilizer should be sprayed as the main method, and ferrous sulfate, phosphate fertilizer, and potassium fertilizer should be sprayed appropriately. If the leaves are big and green and the branches are too long, it indicates that the nitrogen fertilizer is sufficient. Phosphate fertilizer and potassium fertilizer should be sprayed mainly, and some trace elements should be sprayed appropriately. For trace elements, foliar spraying is the main method, and its effect is better than soil fertilization.