Rot, also known as skunk, is a disease of the branches. Most of the diseases occur on the main and lateral branches of the trunk, the disease is easy to occur on the face of the branches, and the branch is also easy to occur. The early stage of the disease is reddish-brown, oval or not plastic, water-stained, slightly swollen, with finger pressure, the disease is sunk. The tissue of the diseased part is rotten, sometimes overflowing reddish-brown juice, emitting a smell of lees. In the later stage of the disease, small warty protrusion appears on the surface of the disease skin, gradually breaking through the epidermis, revealing small black dots, that is, the child base and conidium of pathogenic bacteria. The surface color of the disease part turns dark, gradually turning into black brown to carbon black, dry shrinkage and collapse and cracking occurs at the junction of disease and health. When the disease is severe, the tree body dies partially or completely.
1. Soil quality: According to the survey of the pear area, the disease is generally heavier in the pear orchard with sandy soil, and lighter in the pear orchard with green sand soil.
2. Reason: the disease of bearing trees and old trees more than seven or eight years is more serious. Results Poor management and insufficient water and fertilizer were easy to develop.
3. Branches: Most of the lesions occurred on the coarse stems of the first and second branches, while the trunk and branchlets were less affected. The spots are generally southwest, and most of them are on the side of the branches. The branches of the tree are also prone to disease. In the north and northwest plateau areas, the occurrence of rot disease is often related to freezing damage and sunburn.
4. Varieties: There are differences in disease resistance between species and varieties, such as Xiyang pear more serious disease, Chinese pear varieties such as Yue pear, Huang pear, Meifang pear, etc., followed by Jingbai pear, Qiubai pear, Cipear, Yaria pear and Japanese pear system in the 20th century. China's Huagai pear has the strongest resistance to this disease. In the provinces, no cases were found in those who used birchapple pear as rootstock.
Agricultural prevention and control (1) According to local conditions, the selection of disease-resistant varieties, western pear system disease is more serious, crispy pear, yellow pear, apple pear is also heavily affected. Ypear, white pear generally mild disease. (2) Strengthening cultivation, doing everything possible to enhance tree potential, prevent freezing, and improve disease resistance is the fundamental way to prevent and control rot. Reasonable intercropping should be carried out in the pear orchard, increasing the application of base fertilizer, topdressing in the appropriate period, careful pruning, appropriate thinning of flowers and fruits, adjusting the load, balancing the year, preventing early leaf fall, improving the nutrition level of the tree, controlling the greening and fruitless growth in the later period, so as to strengthen the disease resistance and cold resistance of the tree. In the growing season, timely cut off the dry peg, diseased tip, diseased cut, diseased fruit table and cut the dead tissue of the sawcut with poor healing, so as to reduce the infection of rot bacteria. (3) Heavy scraping 6-8 months with a sharp scraper to scrape the trunk disease skin surface, generally to scrape 1mm surface live skin, to expose the white green skin, pay attention to scrape the diseased tissue. Thin parts of the bark, such as branches, should be carefully scraped to prevent scraping through the bark. (4) On the basis of scraping the disease tissue and rough skin on the trunk and main branch, spraying with permeable and long-lasting fungicides, eradicating latent rot bacteria on the bark, preventing bacteria infection and preventing disease. (5) In the early stage of the disease, timely curettage in small lesions. The inspection interval time should be arranged according to the tree potential and the incidence situation, and the focus should be on preventing the onset of summer, autumn and winter and spring. Be sure to scrape when scraping, there is no rotten under the bark, can only scrape the epidermal disease layer; For deeper lesions, the xylem and the diseased skin should be shaved. (6) Collect the scraped remnants, concentrate on deep burial or burning, and remove the source of the disease. (7) In strong winter areas, the putrefactive skin scraped before winter is coated with white coating. The preparation method: 6 kg of lime, 1-3 kg of salt, 20 kg of water, first dissolve the lime into lime milk, and then add salt and enough water. (8) The larger part of the trunk and main branch scars can be bridged or footed to help restore the tree.
1. Strengthening cultivation, enhancing tree potential and improving tree disease resistance are the fundamental measures to prevent rot. 2. Thoroughly remove diseased dead branches and pruned branches from trees and burn them outside the garden. 3, chemical control: prevention can be broken/rot/spirit 200-400 times liquid plus silicone for the whole garden spray. After two thirds of the leaves fall, the fruit is picked. At the early stage of the disease, it can be used to brush 30-60 times the liquid brush dry, and brush the tree trunk after scraping off the disease. If the disease is serious, the root can be irrigated with 200-300 times liquid gavo / 600 times liquid gavo/abundant/vegetarian once or twice, and the capillary root area can be irrigated thoroughly. It can spray bright/fruit/An 600 times liquid Gavo/abundance/hormone 1000 times liquid 4 times throughout the year to strengthen the strength of the tree and improve the resistance to disease. END