During the spring and summer seasons, after flowering, fruit trees are susceptible to various diseases (physiological diseases, pathogenic toxin diseases) of fruit trees. In addition to the necessary pharmaceutical precautions at this stage, timely application of P and K fertilizers is also a better choice. However, many fruit growers tend to only apply topdressing nitrogen fertilizers (such as urea and high-nitrogen compound fertilizers) during the Spring Festival and ignore the application and supplementation of phosphorus and potassium elements. Therefore, from the physiological needs of fruit trees and disease prevention techniques, it is necessary to apply the appropriate amount of P and K fertilizers 2 to 3 times before flowering.
Phosphorus and potassium are the "good medicines" for disease resistance of fruit trees. Rational application of phosphorus and potassium fertilizers can not only effectively prevent and control the physiological diseases of fruit trees, but also prevent infectious diseases. Many diseases of fruit trees can be alleviated by increasing phosphorus and potassium fertilizers. The test data shows that the application rate of fruit rust is 25 or 40 kilograms of superphosphate and 5 kilograms of potassium chloride in an orchard per acre (667 square meters).
Phosphorus and potassium fertilizers can prevent physiological diseases of fruit trees mainly because: Some physiological diseases are caused by insufficient supply of phosphorus and potassium. Phosphorus and potassium can harden the bark and cells of the fruit, and pathogens and viral agents are less likely to invade. At the same time, phosphorus can promote the absorption of silicon by fruit trees and enhance the disease resistance of fruit trees.
After applying phosphorus and potassium fertilizers to fruit trees, the stems are hard and able to resist adverse environmental conditions and resist the infection of external pathogens, thereby reducing the incidence of fruit trees. In addition, phosphorus can also promote the respiration and oxidation of fruit trees. When pathogenic microorganisms invade fruit trees, they can produce certain toxins and poison pathogenic microorganisms (bacteria). The addition of P and K fertilizers can also reduce the degree of water loss in diseased fruit trees, compensate for the loss of nutrients and moisture caused by pathogenic microorganisms, and improve disease resistance.
Phosphorus and potassium are essential elements of fruit trees and "good medicines" for disease resistance, but they are not applied as much as possible. If it is applied too much, it will cause waste, and it will also have an adverse effect on the growth and development of fruit trees. If too much phosphorus is applied, the absorption of certain trace elements (such as zinc, etc.) in fruit trees will be inhibited, resulting in underdeveloped root systems, reduced branching, and a large amount of stale fruit.
Therefore, in the fertilization method, selection of varieties, and application amount, different methods should be adopted according to different fruit tree species, different tree ages, and different soil conditions, such as bottom application, topdressing, and spraying, and diammonium phosphate and superphosphate in the selection of varieties. Calcium, potassium sulfate, potassium dihydrogen phosphate, and potassium humate are excellent. The application amount is determined by the age of the tree and the amount of fruit planted. In general, 20-40 kg of high-quality phosphate fertilizer is applied per acre, and 7-8 kg of potassium fertilizer is applied. The effect of spraying potassium dihydrogen phosphate 1%-3% on leaf surface is better. Spraying before and after flowering is selected to be 2 or 3 times. 7 - Once in 10 days.
Frozen Squid,Frozen Shredded Squid,Fresh Frozen Squid,Frozen Peru Squid Roll
ZHEJIANG RETRONX FOODSTUFF INDUSTRY CO.,LTD , https://www.retronxfoods.com