1. jujube buqu, also known as jujube inchworm, is the "number one enemy" that harms jujube trees. Larvae harms buds, young leaves and flower buds, and spins silk, which hinders the extension of leaves. In severe cases, all leaves can be eaten up, and at the same time, it also harms a lot of crops such as apples, pears, peaches, potatoes and peppers. Jujube Buqu began to emerge in mid-March, and when jujube buds germinated, larvae began to hatch and harm jujube buds. Its main biological characteristics are as follows: every year, pupae are concentrated in the surface soil around the root neck of jujube trees for the winter; The adult is hermaphroditic, and the wingless female moth crawls up the tree, mates with the winged male moth, and lays eggs in blocks under the rough bark; Older larvae eat a lot and have strong drug resistance; Wingless female moths can't pass through smooth objects. Although young larvae can pass through smooth objects, they are easily stuck by sticky objects. Prevention and control methods: When most larvae enter the second instar, they are sprayed with pesticides to poison the larvae. Commonly used pesticides are: 1,5 times of 3.2% methomyl (high chlorine in emamectin benzoate), and 1,2 times of pyrethroid pesticide < P > Second, Carposina niponensis Walsingham, a fruit borer of jujube, is a worldwide pest. Fruit trees such as jujube, apple, pear and hawthorn suffered the most. The insect has 1-2 generations a year, and overwinters with mature larvae spinning in the soil near the trunk to make oblate cocoons (winter cocoons). In June of the following year, when the temperature rose to about 2℃ and the soil moisture content reached about 1%, the overwintering larvae began to be unearthed, spinning under clods, stones and grass roots to make spindle-shaped cocoons (summer cocoons) to pupate, and the peak of excavation was formed after each rain. Adults have no phototaxis and chemotaxis, but they have strong chemotaxis, so it is effective to use the sex attractant of peach moth to attract moths. Adults mostly lay eggs on the back of jujube leaves and fruits, and the first and second generation larvae eat fruits in July and August-September respectively. According to the above biological characteristics, the following comprehensive prevention and control techniques should be adopted on the premise of doing a good job in pest forecasting. Cocoon digging or soil lifting and cocoon elimination: it should be carried out after thawing in spring and before larvae are unearthed. Plastic film mulching: In spring, covering the ground within a radius of 1 cm around the trunk with plastic film can control the emergence of larvae, pupation and adult emergence. Pick up the fallen fruit and eliminate the fallen fruit larvae. Cultivate the soil under the tree to prevent the larvae from unearthed, and cultivate the soil for about cm. Prevention and control of sex attraction: the sex attractant of peach fruit borer was used for prediction and control. Chemical control: When the peak of attracting moths appears for about one week, it is the best time to spray on trees. In general, in the middle and late July and the middle and late August of the year, when the first and second generations of adults are in full bloom, diflubenzuron and 3.2% mirex (high chlorine in emamectin benzoate) are sprayed 15 times, and pyrethroid pesticides can also be used for control 12 times.
Third, the bud-eating weevil Scythropus Yasumatsu Kone et Merimoto, also known as jujube flying weevil, jujube bud weevil, etc., is a Coleopteran pest that eats only buds and young leaves. This insect occurs once a year and overwinters in the soil as a larva. When jujube trees sprout in late April and early May (the temperature reaches 8-2℃), adults come out and eat jujube buds in groups. Adults have suspended animation, the eggs are laid in the gaps of deciduous branches, and the larvae hatch and fall into the soil, where they overwinter for about 1 months. Or spray 48% chlorpyrifos (1-15 times) on the tree to kill the adults on the tree.
fourth, the green blind bug: the blind bug has 4-5 generations a year in our county, overwintering with eggs, with the most serious damage in the germination stage, bud stage, flowering and fruit-setting stage and young fruit stage of jujube trees. Jujube trees were killed during germination, and the terminal buds shriveled, which made the damaged jujube hanging bent, commonly known as "perm disease". The bud stops developing and dries up and falls off. After the young fruit is damaged, the pulp tissue is necrotic, and most of the newly settled young fruit falls off. After the young fruit does not fall off, it will appear necrotic sores in different degrees and cause fruit diseases. Prevention and control methods: Blind bugs usually lie in the daytime and come out at night, and hide on the ground or in the bark under the tree during the day. Therefore, according to their occurrence properties, they should be treated in the morning and evening, and sprayed with tree stems and weeds at the bottom of the tree. 3% chlorfenapyr (imidacloprid microemulsion) can be sprayed 6 times.
5. Jujube rust Jujube Rust is an important leaf disease of jujube trees, which sometimes damages fruits. At the early stage of leaf disease, light green spots scattered on the back of leaves, then gradually turned into light grayish brown, and finally the diseased spots turned yellow-brown, resulting in a protruding summer spore pile. When the epidermis of the lesion breaks, yellow powdery summer spores are scattered. When the damage is serious, the whole tree leaves from August to September, and the tree is weak, which seriously reduces the yield and quality of jujube fruit. The pathogen of jujube rust mainly overwinters in diseased leaves with summer spores, which becomes the primary source of infection in the second year. Sometimes, it can overwinter in the bud as mycelium. In the first ten days of July of the following year, when there was a lot of rainfall and the temperature was suitable, the overwintering summer spores began to sprout and invade the leaves. In the middle and late July, the disease began to occur one after another, and a large number of leaves began to fall in late August. Rainfall and high humidity are important conditions for the occurrence and epidemic of jujube rust.
According to the above characteristics of occurrence and harm of jujube rust, the following measures should be taken for prevention and control: (1) Lower the bacterial source. During the winter dormancy of jujube trees, the diseased leaves should be thoroughly swept away, buried or burned intensively, and the overwintering bacteria sources should be eliminated. (2) Reasonable pruning. Sparse the over-dense branches and improve the ventilation and light transmission conditions in the crown. Do a good job of drainage in rainy season. Short-stalk crops such as beans should be planted in jujube-grain intercropping land near the crown to ensure good ventilation and light transmission of the crown. (3) Chemical control. The spraying period should be determined by climatic factors such as the morning and evening of summer rainy season, rainfall frequency and air temperature. Generally, spraying drugs begins in the middle of July before the onset of the disease, about 15 days apart, and the harm can be controlled by spraying twice lime-doubled Bordeaux solution or triadimefon.