Control techniques of diseases and insect pests in plum trees

Plum trees are easy to be infected with diseases and insect pests under poor management conditions, light ones affect tree development, poor fruit quality, low yield, heavy ones cause tree weakness, short life span, and fruit can not be eaten. Diseases and insect pests are mainly plum bees, heart-eating insects, aphids, red spiders, red spot disease, gum disease and so on. Let's take a look at the pest control techniques of plum trees.

Red spot disease of plum

[hazard characteristics] Plum red spot mainly harms leaves and also infects fruits. In the early stage of the disease, the leaves produce orange-yellow, slightly raised, clear-edged near-circular disease spots, with the disease expanding, the color deepening, the mesophyll of the diseased part also thickening, and many small red particles are produced above, that is, the spore apparatus of the pathogen. At the end of autumn, the diseased leaves turned red and black, sunken on the front, protruding on the back, the leaves curled and small black spots appeared, forming early deciduous leaves. Fruit damage, resulting in orange-red round disease spot, finally red-black, disease spot on a lot of crimson particles, the fruit becomes deformed, can not be eaten, easy to fall off.

[control methods] ① thoroughly cleaned up the diseased leaves and fruits of the orchard and burned them centrally. Pay attention to drainage and reduce the humidity of the orchard. Before sprouting, ② was sprayed with 3-5 Baumetolite-sulfur mixture, and every 10-15 days, 50% carbendazim 600 times or 70% methyl topiramate 800 times, 70% mancozeb 600 times.

Li Shifeng

[hazard characteristics] it occurs one generation a year, and the mature larvae form cocoons in the topsoil layer under the tree to pass the summer and winter. The next year, when the plum tree blossoms, it becomes an adult, flies and copulates at high temperature at noon, lies in the flower or under the calyx in the morning and evening and under the calyx in the cloudy and rainy day, lays eggs in the calyx tissue, generally lays one egg on a flower, and rarely produces two. After hatching, the larvae mostly eat from the fruit surface and reach the core directly after entering the fruit. Each larva only harms one fruit. When the nucleolus is eaten up, the larvae will mature and lose fruit for summer and winter. The nucleolus of the young fruit is eaten and stops developing and falling fruit.

[agricultural control] turn over the tree plate at the beginning of winter and freeze the larvae in the soil to death.

[chemical control] during the de-fruiting period of ① larvae, 25% phoxim microcapsules were sprayed on the ground, or 48% Lexben 200,300 times. After spraying, gently rake the soil to make the soil mix evenly. ② plums were sprayed when 80-90% of the plums were sprayed, 5% cypermethrin 2000 times, cypermethrin 2000 times, and 2.5% deltamethrin 3000 times.

Plum heart borer

[hazard characteristics] the plum heart borer is a small Lepidoptera pest of the family Lepidoptera (more in the area of 40 mi 50 °N). It is the most serious pest that harms plum fruits, with a damage rate of 80% and 90%. The injured fruit often shed teardrop-like pectin at the wormhole, could not continue to develop normally, and gradually turned purplish red and fell off. Because its insect path is full of red insect dung, it is also vividly called "bean paste stuffing".

[control methods] the key periods for the control of plum heart borer are the peak adult and spawning period of each generation and the burying period of the first generation of mature larvae. Spray 90% trichlorfon 0.8% solution, 50% malathion 1% solution, 50% dichlorvos. Before fruit drop, 50% phoxim 1% 1.5% solution was applied once in the soil under the crown of Li Shu. At the end of falling flower (95% falling flower), when the small fruit is the size of wheat grain, spray the first time, using dichlorvos, enemy killing, quick killing, and Laifuling, once every 7 to 10 days. From the point of view of comprehensive control, biological agents can also be used to treat the soil under the canopy, such as Beauveria bassiana. The fallen fruit should be swept away after autumn to reduce the source of insects in the following year.

Aphids

[hazard characteristics] aphids mainly harm the new shoots and leaves of plum trees. When the new shoots were seriously damaged, they curled and grew poorly, affecting photosynthesis, resulting in shedding, affecting the yield and flower bud formation of fruit trees, and greatly weakening the tree potential.

[control methods] ① combined with pruning in early spring, cutting off the damaged branches and destroying them centrally. ② tree spraying: during the peak period of damage, 50% dichlorvos emulsion 1% 1.5% can be sprayed, or 40% dimethoate emulsion 1% 2%, 50% malathion 1%, 50% phoxim emulsion 2%, 50% aphid pine wettable powder 1.5%. ③ reasonably protects or releases natural enemies.

Red spider

[hazard characteristics] Red spiders that harm plum trees are mainly Hawthorn red spider adults and nymphs, sucking leaves and sprouting sap, so that the new buds can not continue to germinate. after the leaves are seriously damaged, the whole leaves become scorched yellow and fall off. Most of the leaves fall off from July to August, sometimes resulting in two blossoms. The seriously damaged plum trees not only can not mature the fruit of that year, but also greatly affect the flower bud formation of the current year and the yield of the next year.

[agricultural control] according to the living habits of Hawthorn red spider, in field management, reasonable intercropping, timely deep turning of tree plate or burying soil, reasonable pruning, proper fertilization and irrigation. It can also be prevented by soil methods, such as spraying garlic juice or mixing washing powder with stone sulfur mixture. At the same time, it is necessary to protect natural enemies in order to give full play to the natural control of insect pests.