1. The moisture content of a live apple tree is generally 70%~80%. Water is a medium, and all important biochemical changes and normal metabolic processes must be carried out in or with the participation of water. The amount of water affects the change of the metabolic direction of the fruit tree. Water shortage of fruit trees often causes various physiological processes to be disordered, seriously affecting the yield of fruit trees. For example, during the year, June, July, and August are the hottest months of the year, and the water evaporated through the leaves of fruit trees to dissipate heat is hundreds of times greater than the amount of water used to produce organic matter. However, it is often found that the soil of some orchards has been severely short of water, and it is said that it is not watered in order to grow flowers. When the temperature exceeds 35 degrees, the soil is short of water, and in order to save life, the fruit tree will close the leaf stomata by itself, reduce the evaporation of water, and will not synthesize nutrients, and will also pump out the water in the fruit to evaporate. Affects fruit growth and flower bud differentiation. Therefore, when the soil is short of water when the temperature is high, it must be watered in time.
2. When the temperature is high, I am most afraid of heavy rain, because of various germs, the higher the temperature and humidity, the faster the infection. A scientific research department has reported that "the temperature exceeds 30 degrees, and the sudden heavy rain is 30 mm (1 plough moisture), and the brown spot fungus and anthracnose leaf blight fungus infect the leaves within 2 hours." The difference is that it takes 12~14 days to complete the infection process after the brown spot fungus infects the leaves, and a large number of leaves are lost. However, after the anthrax leaf blight infects the leaves, the leaves will be green and dry in 3 days. Therefore, if there is a sudden heavy rain in the case of high temperature, it is necessary to take leaf protection medicine in time before or after the rain.
3. Practice has proved that when the temperature is 38 degrees, the soil temperature of the ploughing garden reaches more than 50 degrees, and when the temperature is 40 degrees, the soil temperature of the ploughing garden reaches more than 60 degrees. However, the grass garden and the grass garden, whether it is the air temperature or the soil temperature, are 3~4 degrees lower than the temperature of the clear cultivation garden, and at the same high temperature, the water evaporation of the grass garden and the grass planting garden is slower than that of the clear cultivation garden, and it is drought tolerant. Don't underestimate the grass garden, the temperature of the grass garden is 3~4 degrees lower than that of the clear garden, which is good for root growth, and the leaves also have less transpiration and water. Grassy orchards also increase soil organic matter, and the benefits are endless.
4. Don't spray if the temperature is too high, everyone knows that the temperature is lower than 18 degrees, the effect is not good, the temperature is more than 30 degrees, just apply the medicine, and the medicine on the leaves will evaporate and dry. If the evaporation is too fast, the leaves and fruits are prone to pesticide damage. Therefore, if the temperature is lower than 30 degrees and more than 25 degrees, the effect is good and there will be no pesticide damage. It is best to start at 5 a.m. and finish at 8 p.m., or start at 6 p.m. and continue to administer until evening. Only in this way can the medicine be retained on the leaves for a slightly longer time, and the systemic fungicide can be absorbed into the leaves. Of course, it's better to take pills at night.
5. Ninety percent of an apple is water, and a tree that bears more fruit is less drought tolerant than a tree that does not. In the same high temperatures, the trees that bear more fruit are dry, but the trees that do not bear fruit are not dry. When the soil is short of water, the leaves drain the water from the fruit to dissipate heat. Therefore, in the case of high temperatures, trees with many fruits must be watered in time.
In short: moisture has the effect of regulating temperature, when the temperature is too high. When the sun hits the leaves, it will increase the temperature of the leaves and even scorch the leaves. It is only due to the transpiration of the water that a large amount of heat is emitted, so that the leaves can be kept at a certain temperature without being harmed.
Author: He Jucai, lecturer of Zhongnong Le Fruit Science Research Institute
Source: Zhongnongle