In the one-year growth cycle of apple trees, the tree's resistance to rot was different at different times, and the occurrence of rot was also very different.
Latency
The apple tree sprouts from spring to leaf in November and leaves it as a growth period. It is also a period of disease resistance of apple trees to rot. During this period, the tree photosynthesis, water metabolism and other physiological activities are vigorous, can produce a large number of nutrients, and have strong resistance to rot disease. Therefore, in addition to individual orchards with poor management, weak growth, and poor disease resistance, the control of calcium deficiency in most apple orchards does not occur or rot occurs. In the northwestern fruit region of China, apple trees began to produce wavy skin in June and peaked in July. In August, rot bacteria could be isolated on wadding skin. At the end of October, no rot lesions were observed in the healthy tissues under the burdock skin. It shows that in the disease-resistant period of apple trees, rot pathogens mainly parasitize dead tissue of dead skin, and generally do not spread to healthy skin and form rot lesions. During this period, the orchards saw rot lesions of varying sizes that were mostly leftover lesions that did not cure in the spring.
Onset period
The apple tree sprouts from the leaves (November) to the spring of the following year (late March or early April) as a dormant period, and it is also the period of apple tree rot disease. Before the apple tree defoliates, a large amount of nutrients in the tree flow to the fruit. After deciduous, photosynthesis, water metabolism and other physiological activities are basically stopped. The content of nutrients such as sugar and nitrogen reaches the lowest level, and the tree is in a state of starvation and disease resistance. Very weak, the most prone to rot.
From February to March in spring (before leafing), it is said that the temperature gradually rises at the later stage of disease. The temperature of apple comprehensive prevention and control measures in cottonseed meal is suitable for the growth and reproduction of rot bacteria, and the rot bacteria on dead skin tissue will quickly invade health. Bark forms new lesions. The original small lesions will rapidly expand and become large lesions after more than 10 days, which is the peak period of rot disease. After the buds have emerged from the apple tree, they enter the stage of disease resistance and rot disease ceases to develop.
Kn95 Respirator,Kn95 Filters 3D Mask,Kn95 5 Layers Cup Face Mask,Nonwoven Cloth Kn95 Face Mask
Jiangmen anjian biotechnology co. LTD , https://www.anjianmask.com