How to spray foliar fertilizer on fruit trees

Foliar fertilizer spraying of fruit trees is to prepare solid fertilizer into an appropriate concentration of aqueous solution, spray it on the leaves, enter the tree through epidermis cells and stomata, and give full play to the fertilizer effect. This method is simple and easy, uses less fertilizer and plays a role quickly. It can meet the urgent need of nutrient elements for fruit trees, and is conducive to the correction of element deficiency. The scientific application of foliar fertilizer to fruit trees can get twice the result with half the effort. 1. According to the characteristics of fertilizer, the type of fertilizer is selected. It is often used in foliar fertilizer with good effect, such as urea, potassium dihydrogen phosphate, potassium sulfate, potassium chloride, ammonium nitrate, ammonium phosphate, calcium superphosphate and plant ash leaching solution and some micro-fertilizers. Volatile ammonium bicarbonate and other fertilizers are not suitable for foliar fertilizer. 2. According to the types of fruit trees and the purpose of topdressing, the spraying concentration and spraying period were determined. The suitable concentration of foliar fertilizer spraying is generally: urea 0.3% 0.5%, potassium dihydrogen phosphate 0.2% 0.3%, ammonium phosphate 0.3% 0.5%, boric acid 0.1% 0.5%, borax 0.1% 0.5%, ferrous sulfate 0.1% 0.4%, plant ash 1%. In order to improve the fruit setting rate of apples, pears, grapes, etc., 0.3% 0.5% urea and 200 times borax solution can be sprayed at the flowering stage; 0.2% potassium dihydrogen phosphate can be sprayed during the fruit expansion period to promote fruit coloring; in order to improve the nitrogen reserve nutrition of the tree, a high concentration of 35% urea can be sprayed after fruit harvest in autumn. The concentration of fertilizer solution should be low in the early stage of fruit tree growth, and can be increased in the middle and later stage. 3. According to the climatic conditions, the suitable spraying time is selected. Foliar fertilizer spraying should be carried out in relatively humid weather, when keeping the leaf moist time 30: 60 minutes, the fertilizer effect is the best. In order to prolong the preservation time of fertilizer liquid on the leaf surface as much as possible, it is best to do it in the morning and evening when the air is moist and the dew is not dry. On cloudy days without wind, it can be sprayed all day. If an appropriate amount of adhesive is added to the fertilizer solution, the spraying effect can be improved obviously. 4. According to the movement of fertilizer in the tree, the times of fertilizer spraying were determined. The mobility of nitrogen and potassium in the tree is very strong, and it can be sprayed once in the critical period of fruit tree growth; the mobility of phosphorus is inferior to that of nitrogen and potassium, which needs to be sprayed twice according to the growth of the tree; zinc and copper only partially move, boron, calcium and other trace elements do not move, and should be sprayed continuously for 2 times in order to achieve the desired effect. In addition, when spraying foliar fertilizer, mixed pesticides can be added at the same time to save labor and time.