Is there any skill in spraying foliar fertilizer on fruit trees?

Is there any skill in spraying foliar fertilizer on fruit trees? What do fruit trees need to pay attention to when spraying foliar fertilizer? Is there a netizen to help introduce that foliar fertilizer spraying on fruit trees is the main form of extra-root topdressing, which has the advantages of small amount of fertilizer, fast absorption, remarkable fertilizer effect, strong pertinence, not fixed by soil, not restricted by the absorption function of roots, and so on. The planting network has sorted out some skills and matters needing attention for spraying foliar fertilizer on fruit trees, which are listed below for netizens' reference. Technique one, spray for symptoms: it should be based on the principle of what is missing and what to make up. If the young leaves, especially those at the top, die at the tip and margin or along the midrib, it means calcium deficiency; if the veins are green, the mesophyll is yellowish or white, and the symptoms gradually develop from the young leaves to the old leaves, it means iron deficiency; if the leaves are slightly green and wrinkled, sometimes they are unusually thick and fat, and in severe cases, the shoots die downward at the top, indicating boron deficiency. If the branches of the plant are too long and the leaves are fat and green, it shows that the nitrogen fertilizer is sufficient, we should spray phosphorus and potassium fertilizer mainly, and spray some trace element fertilizer properly. Second, choose the right foliar fertilizer: ammonium bicarbonate in nitrogen fertilizer and phosphate rock powder in phosphate fertilizer are ineffective or harmful to foliar spraying, and spraying is strictly prohibited. Suitable for foliar spraying are urea, calcium superphosphate, potassium sulfate, potassium dihydrogen phosphate and boric acid (borax) zinc sulfate, manganese sulfate, ferric sulfate, ferric citrate, agricultural aspirin, calcium oxide, magnesium sulfate, lime water and so on. If possible, we can also choose amino acids and humic acid biological micro-fertilizers, such as amino acid chelate calcium, black humic acid, brown humic acid and so on, which have the effects of improving fruit quality, drought and cold resistance, disease prevention and disease resistance and so on. Technique 3. Choose the appropriate spraying time: extra-root topdressing mainly absorbs nutrients through plant stomata and stratum corneum, which can be carried out throughout the growing season. The physiological function of young leaves is exuberant, the proportion of stomata is large, the absorptive capacity is the strongest, and the effect is the most obvious. Fruit trees have different fertilizer requirements for different periods, so they should be flexible. For example, calcium fertilizer should be sprayed 40 days after flowering and 40 days before fruit harvest; iron fertilizer should be sprayed before sprouting and autumn shoots should be sprayed for a long time; boron fertilizer should be sprayed at full flowering stage (50% blooming). Fertilizing outside the root should be carried out on cloudy days without strong winds, and if sunny, it should be sprayed before 9: 00 a.m. and after 4: 00 p.m. Ammonium molybdate or sodium molybdate is 0.01%, copper sulfate is 0.01% Mel 0.02%, Manganese sulfate is 0.05% Mel 0.1%. The concentration of foliar fertilizer spraying should generally be controlled below 0.5% to prevent fertilizer damage. Tip 5: choose the spraying part of the fruit tree: spray fertilizer to the back of the leaf as far as possible, because there is a layer of horny layer on the front of the leaf, water is not easy to enter, there is no horny layer on the back of the leaf, and there are many stomata, fertilizer is easy to be absorbed. In addition, foliar spraying should not only spray the outer part of the crown, but also spray the branches and leaves of the inner chamber of the crown; spray not only the upper leaves, but also the middle and lower leaves. Technique 6: do not mix at will: in order to improve work efficiency, foliar fertilizer should be sprayed with mixture. The mixture can be divided into foliar fertilizer + insecticide, foliar fertilizer + plant growth regulator; foliar fertilizer + insecticide + fungicide; foliar fertilizer + insecticide + fungicide + plant growth regulator. However, we should pay attention to the respective performance of these fertilizers and pesticides to see if they can be mixed, otherwise they will not only have low fertilizer and drug efficacy, but also cause fertilizer and drug damage. Click to get more foliar fertilizer application methods