Pear tree rot and its control

1. Disease prevention of strong trees: (1) reasonable burden: according to the growth status of the tree and the level of fertilization, determine the appropriate amount of fruit, do not let the tree bear too much, let alone take too many measures to increase fruit, such as branch pulling and ring peeling for short-term benefits. It is necessary to properly thinning flowers and fruits so that the fruit can grow without mistake. (2) increasing fertilizer and water: for the vast pear areas in the north, the more common phenomenon is the lack of fertilizer and water. In fertilization, we should pay attention to the application of organic fertilizer, phosphorus fertilizer, potassium fertilizer and trace element fertilizer, but not too much nitrogen fertilizer. (3) protecting leaves and promoting roots: timely control of diseases and insect pests that cause early fallen leaves, such as scab, gray spot, black spot, brown spot, red spiders, pear net bugs, aphids, leaf rollers, etc. At the same time, we should also pay attention to the prevention and control of various root diseases. two。 Avoid and protect the wound: (1) thoroughly control branch pests: Jiding, Spodoptera litura, longicorn beetles and other branch pests are not only the makers of wounds, but also the vectors to carry and spread germs. thorough control of these pests is very important to the vast pear area. (2) prevent frost injury and sunburn: the sunny side of the pear branch has a large temperature difference between day and night, so it is easy to suffer frost injury; if there is no leaf cover on each sunny side, the pear is easy to die from the sun in summer. The more effective measures to prevent frost damage are: first, the trunk is painted white to reduce the temperature difference between day and night; the other is that the trunk is bundled with grass to cover and prevent freezing. The formula of commonly used whitening agent is 12 kilograms of quicklime. Add 2 kg of stone-sulfur mixture (about 20 Baume), 2 kg of salt, 36 kg of water, or 10 kg of quicklime, 3-4 kg of soybean milk and 40-50 kg of water. Painting white can also prevent branches from burning in the sun. (3) to protect the wound: the larger saw blade should be cut flat, and then protected by tung oil, varnish or Topurazine ointment, Smur921 antibacterial agent and so on. After the larger lesion is cured, it should be bridged and protected in time. 3. Timely treatment of disease spots: (1) scraping bark: scraping off warped bark and necrotic tissue before pear sprouting, scraping combined with spraying or spraying. It can be sprayed with 300-fold solution of 50% formearsine wettable powder, or 1% 3-degree stone-sulfur mixture. (2) Drug treatment of lesions: after scraping off the diseased tissue, evenly smear the disease part with 1 part of 70% methyl Topurazine powder plus 2.5 parts of vegetable oil, or 1 part of 50% carbendazim wettable powder plus 1.5 parts of vegetable oil. It can also be smeared with Baume 5-10-degree stone sulfur mixture, Smur921 antibiotic 20-fold 30-fold solution, 40% Fumet arsine 50-fold solution or 30% decaying enemy 30-fold solution, 843 rehabilitation agent original solution, Wuningmycin fermentation broth 5 times liquid, etc., in order to prevent scar recurrence. The exposed xylem can be smeared with coal tar or antirust paint, and the disease scars on the larger trunk can be bridged in time to restore the tree potential as soon as possible. Scrape off the bark and diseased branches and burn them centrally.