How to carry out foliar topdressing of fruit trees

First, the type, period and dosage of fertilizer spraying. Nitrogen fertilizer should generally be used in the early and later stages of fruit tree growth, properly combined with phosphorus and potassium fertilizer. Proper spraying concentration can effectively promote shoot growth, increase fruit yield and be beneficial to flower bud differentiation. The concentration of urea in the early stage is 0.2%, 0.3%, 0.3%, 0.5%, 0.5%, 0.5%, 0.5%, 0.5%, 0.3%, 0.5%, 0.5%, 0.5%, 0.5%, 0.5%, 0.5%, 0.5%, 10%, 0.5%, 0.5%, 0.5%, 10%, 0.5%, 0.5%, 0.5%, 0.5%, 10%, 0.5%, 0.5%, 0.5%, 0.5%, 10%. Phosphate fertilizer spraying should grasp the principle of less in the early stage and more in the middle and later stages. The effect of ammonium phosphate is the best, the concentration is 0.5% mi 1%, the concentration of potassium dihydrogen phosphate is 0.2% mi 0.5%, and the concentration of superphosphate leaching solution is 1% mi 3%. Potash fertilizer is mostly used in the middle and later stages. It can effectively promote fruit coloring, improve fruit quality and enhance disease resistance. The concentration of potassium sulfate and potassium nitrate is 0.3% Mo 0.5%; plant ash is soaked in 5-15 kg water and 0.5 kg ash for 24 hours, then the residue can be filtered and sprayed. trace element. If leaflet disease is found in the previous year, 3% Mel 5% can be sprayed one month before sprouting, and 0.15% Mel 0.25% zinc sulfate solution can be sprayed during the growing period. When it is found that the leaves are green and yellowish white, 0.3% Mel 0.5% ferrous sulfate solution can be sprayed every half a month during the growing period. When it is found that the fruit is deformed and has dry spots on its appearance, 0.3% Mel 0.5% borax solution can be sprayed before and after flowering in the following year. Second, spraying time. In order to prolong the time of leaf fertilizer absorption and improve fertilizer use efficiency, foliar topdressing should be carried out before 10:00 and after 4 o'clock in the afternoon, and the effect of spraying was the best in semi-cloudy and windless days. Spraying nitrogen fertilizer at full flowering stage can increase fruit setting rate; spraying nitrogen fertilizer at young fruit stage can promote young fruit expansion; spraying nitrogen fertilizer combined with phosphorus and potassium fertilizer in May and June can effectively promote flower bud differentiation; spraying phosphorus and potassium fertilizer in the later stage can increase fruit sugar content and promote coloring; trace elements can be sprayed before and after flowering. Third, spraying method. Foliar topdressing can be carried out alone, or several fertilizers can be sprayed mixed with pesticides to save labor. However, it should be noted that mixed spraying between fertilizers or mixed with pesticides can not produce fertilizer or drug damage. Urea is a neutral fertilizer and can be mixed with many kinds of pesticides, and pesticides and fertilizers with different acids and bases can not be mixed. For example, all kinds of micro-fertilizers can not be mixed with plant ash, lime and other alkaline fertilizers, and zinc fertilizer can not be mixed with calcium superphosphate. Before the mixed use of fertilizer and pesticide, put a small amount of fertilizer solution into the same container, if there is no turbidity, precipitation, bubbles and other phenomena, it shows that it can be mixed, otherwise it can not be mixed. Foliar topdressing should be first up and then down, uniform and thorough, mainly spraying the back of leaves.