How to prevent diseases and insect pests of plum trees in spring

First, improve the lighting. In the greenhouse, measures such as hanging fruit branches, reasonable pruning and laying reflective film can be adopted to improve ventilation and light transmission and reduce the incidence of diseases and insect pests. Reasonable pruning of ①. The elongated head of each backbone branch retained only one or two vigorous new shoots in the appropriate direction, and the rest were thinned. If the fruiting branch is overgrown, there is only a flat and oblique new shoot in front of the fruit tip. Cut off the branches of diseases and insect pests in time and remove the fruitless branches. Properly cut short and partially shade the new tip. Sweep away fallen leaves and fruits, burn or bury deeply. ② hanging fruit branch. First, use No. 16 iron wire to form a grid of 2 × 2 meters in the shed, 1.8 meters from the ground, pull the long fruit branches to the crown with string to form an oblique standing branch, adjust the long fruit branches to the lack of branches space, and tie the string to the wire. ③ was coated with reflective film. Through hanging branches and pruning, a 0.3-0.4 meter wide light transmission band is left between the rows, and a 1 meter wide aluminum foil single-layer reflective film is laid under the light transmission band. Second, reduce the humidity. Covered with plastic film in the facility, ventilation and humidity reduction, furrow irrigation and hole irrigation under the film, proper increase of greenhouse temperature and timely elimination of stagnant water were adopted after the hard core period, so as to reduce the air relative humidity, increase the transpiration rate of fruit and reduce the occurrence of diseases. Third, prevention and control of diseases. Before the plum tree blossoms, the branches are easy to be infected with gum disease, so that the branches are weak, the buds are not strong, it is difficult to set fruit, and when serious, the branches are dry and unable to blossom and bear fruit. Therefore, pay attention to check the branch tip of the plum tree and find that there is a gelatinous flow out from the branch tip. Scrape the gel off with a knife and coat it with a layer of stone-sulfur mixture residue, or Bordeaux solution, or 25% pure alkali solution, or 1% potassium permanganate solution. Before flowering, the internal shoots were sprayed with 0.6-0.8 Baomedo stone-sulfur mixture aqueous solution or 600-fold copper oxychloride aqueous solution for 1 or 2 times to kill the bacteria adsorbed on the branches, and the plum branches could be infected with gum disease before flowering. After the young sepal of plum fruit fell off, combined with foliar fertilization, the mixture of 1000 times of mancozeb wettable powder and 1000 times of carbendazim wettable powder was sprayed every 10 to 15 days to prevent perforation and so on. When spraying fungicides, if the red spider occurs, it can be mixed with 15% pyridaben EC 2000-3000 times or 1.8% avermectin 4000-5000 times. If aphids occur, 10% imidacloprid wettable powder can be mixed with 3000-4000 times solution. Fourth, prevent and control insect pests. When sprouting, spraying with 20% aphid-killing EC 1000-1500 times, or 10% cypermethrin EC 2000-4000 times, or 50% bacillus special wettable powder 800-1000 times, can effectively control overwintering aphids, and has a good repellent and control effect on beetles. After leaf spreading, combined with foliar fertilization, spray the mixture of 70% mancozeb 800 × 1000 times and 50% carbendazim wettable powder 1000 times every 10 days to prevent disease and protect leaves. When spraying fungicides, such as aphids and moths, they can be mixed with 20% aphid EC 1000 × 1500 times; if red spiders occur, they can be mixed with 15% pyridaben EC 2000 times 3000 times, or 1.8% avermectin 4000 times 5000 times. 1.5% phoxim granule 5 kg per mu was applied to control grubs and other underground pests. Fifth, avoid mixed planting. Avoid mixed planting with other drupe fruit trees to prevent the spread of diseases and insect pests.