Plum trees are easily infected with diseases and insect pests under poor management conditions, which affects the development of trees, poor fruit quality and low yield. In severe cases, the tree is weak, the life span is short, and the fruit is inedible. The main pests and diseases are plum bees, fruit eaters, aphids, red spiders, gummosis and so on. Let's take a look at the pest control technology of plum trees!

plum red leaf spot

Harmful characteristics: plum blossom spot disease mainly harms leaves and also infects fruits. In the early stage of leaf infection, orange-yellow, slightly convex, nearly round and clear-cut spots appear on the leaves. With the expansion of the disease, the color deepens, and the mesophyll of the affected area thickens, producing many little red dot, that is, pathogen spores. At the end of autumn, the diseased leaves turn red and black, concave in front and convex in back, the leaves curl and appear black spots, forming early deciduous leaves. When the fruit is damaged, it produces orange-red round spots, and finally it is red and black. There are many dark red spots on the diseased spot, and the fruit becomes deformed, inedible and easy to fall off.

Prevention and control methods ① Thoroughly clean the diseased leaves and fruits in the orchard and burn them centrally. Pay attention to drainage and reduce the humidity of orchard. (2) Spraying 3~5 Baume sulfur mixture before germination, and spraying 600 times of 50% carbendazim or 800 times of 70% thiophanate methyl and 600 times of 70% mancozeb every 10~ 15 days during the growth period.

Li Shifeng

The damage characteristics occur once a year, and the mature larvae cocoon on the topsoil under the tree and overwinter in summer. In the following year, plum trees bloom, adults emerge, fly to mate at high temperature in the afternoon, and lie under flowers or calyx in the morning and evening and rainy days. Eggs are laid in calyx tissue, usually one egg is laid on a flower, and two eggs are rarely laid. After hatching, the larvae mostly feed on the surface of the fruit and go straight to the stone after entering the fruit. A larva only harms one fruit. When the nucleolus is eaten up, the larvae will also mature and lose fruit and overwinter in summer. The young fruit nucleolus is eaten, stops developing and drops fruit.

Agricultural prevention and control in early winter, turning over the tree tray and turning over the soil surface to freeze to death.

Pesticide control ① During defoliation of larvae, spray 25% phoxim microcapsule or 48% chlorpheniramine on the ground for 200~300 times, and then lightly rake the soil after spraying, so that the pesticide can be mixed with the soil evenly. (2) When plums have 8-9 flowers, spraying 5% beta-cypermethrin, 2,000-3,000 times of fenpropathrin and 3,000 times of 2.5% deltamethrin.

Eat the heart of plums

Harmful characteristics: the fruit borer is a lepidopteran pest (latitude 40? 50? Is the most serious pest that harms plum fruit, with a damage rate as high as 80%? 90%。 The damaged fruit often oozes teardrop pectin in the wormhole, which can not continue to develop normally and gradually turns purple and falls off. Because its wormway is full of red dung, it is also called bean paste stuffing figuratively.

Prevention and control methods The key period of prevention and control of plum moth is the peak period of adult and oviposition of each generation, and the burial period of 1 generation mature larvae. Spraying 90% trichlorfon 0.8% solution, 50% malathion 1% solution and 50% dichlorvos. 50% phoxim 1% ~1.5% solution was applied before and under the crown of plum tree. At the end of blooming (95%), when the small fruit is big, spray 1 time, and use dichlorvos, enema, chlormequat chloride and Laifuling, and spray 1 time every 7 ~ 10d. From the point of view of comprehensive control, biological agents can also be used to treat the soil under the crown, such as Beauveria bassiana. After autumn, the fallen fruits should be swept away to reduce the source of insects in the next year.

aphid

Hazard characteristics Aphids mainly harm Li Shuxin sharp leaves. When the new shoots are seriously damaged, they will curl and grow poorly, which will affect photosynthesis and even fall off, affect the yield of fruit trees and the formation of flower buds, and greatly weaken the tree potential.

Prevention and control methods ① early spring combined with pruning, cutting off damaged branches and centralized destruction. (2) tree spraying: at the peak of damage, 50% dichlorvos emulsion 1% ~ 1.5% solution, 40% dimethoate emulsion 1% ~ 2% solution, 50% malathion 1% solution and 50% octanol. ③ Reasonable protection or introduction of natural enemies.

red spider

Hazard characteristics: The red spider that harms plum trees is mainly the adult and nymph of red spider of hawthorn, which sucks the juice of leaves and initial germination, making the new buds unable to germinate. After the leaves were seriously damaged, the whole leaves turned yellow and fell off. In July and August, most leaves fall off, sometimes causing two blooms. The severely damaged plum trees not only failed to mature in that year, but also greatly affected the formation of flower buds in that year and the yield in the next year.

Agricultural control According to the living habits of tetranychus viennensis, in field management, it is necessary to intercrop reasonably, turn over the tree tray or cover the soil in time, prune reasonably, and apply fertilizer and water appropriately. It can also be controlled by indigenous methods, such as spraying garlic juice or mixing washing powder with sulfur mixture. At the same time, it is necessary to protect natural enemies and give full play to their natural control of pests.

Chemical control ① dormant period: the purpose is to reduce the population base as much as possible. Spraying a mixture of 5% anthracene oil emulsion and 3-5% sulfur before fruit trees germinate. In addition, before the plum tree germinates in early spring, combined with the prevention and control of other pests, all the warped skin and coarse skin on the trunk and main branches are scraped off and burned centrally. (2) After germination: at the peak of overwintering females, when 1 generation eggs hatch, water can be added to dilute 20% dicofol wettable powder, 1.5% solution, 0.8% solution of 20% omethoate emulsion or 0.6% ~ 1% solution for control. All kinds of acaricides should be used in turn to prevent insects from developing drug resistance and improve the control effect.

Plum gummosis

Harmful characteristic gummosis is one of the serious diseases in plum orchard in recent years, and fruit farmers often feel helpless. Gummosis mainly harms Li Shusheng Branch. After injury, the cortex of the plum branch swells into a bubble shape, and then the soft and transparent colloid flows out one after another. After contact with air, the gum turns reddish brown to brown, and after drying, it becomes a block. The diseased cortex and xylem turn brown and necrotic, which affects the vitality of the tree. In severe cases, some branches dry up and even the whole plant dies. This disease occurs all year round, especially in high temperature and rainy season.

Agricultural prevention ① Pay attention to soil management: clear the garden in time, loosen the soil and fertilize, dig through the drainage ditch to prevent soil water accumulation, and apply more manure or bran fertilizer rich in organic matter and phosphorus and potassium fertilizer to keep the soil loose, so as to facilitate root growth, enhance tree vigor and reduce diseases. (2) timely control of borers such as longicorn beetles, and eliminate the cause of disease. (3) Strengthen crown care: Prune reasonably, and don't over-prune. Attention should be paid not to damage the trunk cortex during plum orchard operation, and timely irrigation in dry and high temperature season can also effectively prevent the occurrence and harm of diseases.

May-June is the suitable period for chemical control, and 2000-2500 times of 12.5 diniconazole (Tebaohe) wettable powder or 500 times of 25- methyl ethyl (Keteling) wettable powder can be sprayed every 15 days for 3-4 consecutive times.