Control of Psilocycterus sp. on Jujube Trees

Jujube trees are generally common in the north, but relatively rare in the south. For those who plant jujube trees, what they fear most is the erosion of pests. Once the jujube trees are eroded by pests, not only the yield will decline, but the fruit will be bitten by insects. More serious, it will cause jujube trees to wither.

Control of rust gall mites in jujube trees

Jujube rust gall mite is commonly known as jujube rust wall lice. Harm jujube and sour jujube. The green parts such as feeding leaves, flower buds, flowers, young jujubes and detached branches are absorbed by adult and nymph mites, and the damaged parts are either silver-gray rust spots, or dry and shedding, and the seriously damaged trees or plots can be cut off.

Adult mite, body length about 0.15 mm, wedge-shaped; milky white at first, light brown later, translucent; 2 pairs of feet, located in the anterior segment; chest plate shield-shaped; mouthparts pointed and slender, bent downward; back and ventral part of the back is heterocyclic structure, about 40 rings on the back, with a pair of stout bristles in front, middle and back, and a pair of equal tail hairs at the end. Egg, globose, milky white, surface. Smooth and shiny. The nymph is white and translucent at first hatching, and its shape is similar to that of adult mites.

The rust gall mite of jujube overwintered as an adult mite in the old bud scale of jujube. In the middle of April next year, the overwintering adult mites in the sprouting stage of jujube trees are stinging, which harms the tender buds and young leaves. The blooming stage of jujube tree entered the peak period of damage in early June, and the damage began to appear. the insect population density was the highest in the middle of June, and the pest mite propagated most rapidly in June, which was the peak period of the whole year. In the high temperature stage from the middle of July to August, most of the insect bodies were transferred into the old bud scales of jujube, and the number of insect population in leaves decreased significantly. The reproduction rate decreased in September and the insect population density was the lowest, and all the insects were stung and overwintered at the end of September. The annual damage period is five and a half months. After the damage to the leaf, the base of the leaf and along the leaf vein first appeared slightly gray-white at first; with the increase of insect population density, the symptoms gradually spread throughout the whole leaf, the leaf color was extremely gray and senile, the leaf texture was thick and brittle, and closed slightly to the leaf surface along the midrib; in the later stage, the leaf margin became scorched, which often led to early defoliation. After being damaged, the buds and flowers gradually turn brown and dry and fall off. After the fruit was damaged, it showed silver-gray rust spots, and the fruit withered and fell off in the later stage.

Prevention and control methods. Can be mastered in late May or early June jujube tree florescence, spray 40% omethoate EC. 1500 times or 20% dicofol emulsion 1000 times. These two kinds of different properties of agents, it is best to cross-use, can delay the emergence of drug resistance of the mites, but also can spray Baume 0.3-0.5 degree lime-sulfur mixture. When spraying, you should pay attention to the spray on the inner chamber of the crown and the back of the blade. As long as spraying is timely, rigorous and meticulous, the occurrence and harm of the mite can be controlled and the yield and quality of jujube can be guaranteed.

Disease and pest control of jujube

1. Disease: jujube mad disease can be cured in the same year and bear dates in two years by injecting liquid into the trunk of Jujube Mad No. 1 and Jujube Mad No. 2. Regular spraying of compound Zaohongbao can reduce the incidence of fruit shrinking disease from more than 80% to less than 15%. Other diseases were sprayed under the trees of the whole orchard before germination, and the other diseases were sprayed with 5 Bordeaux stone sulfur mixture under the trees in the whole orchard before germination. in the middle and last ten days of June, mancozeb, verapamil and trimethoprim EC were sprayed every 15 days in the first ten days of July. a total of 2 to 3 times, in late July, spraying Bordeaux liquid, other diseases can be controlled.

2. Insect pests: jujube gall midge should be controlled with dichlorvos plus diuretic before rolling leaves after germination in spring. If the first generation is sprayed again on the 10th day after the occurrence of the first generation, the occurrence of future generations can be controlled. Before and after the wheat harvest, the newly hatched larvae crawl out of the mother, and the wax shell has not yet secreted wax. Omethoate is used to control the critical period. When jujube bugs occur, the enemy is used to kill EC to prevent and control. Pyrethroids were used to control the occurrence of jujube buqu and diamondback moth. From July to October, longicorn beetles can kill longicorn beetle larvae by scraping off the topsoil around the root neck with a small shovel, finding the wormhole, injecting dichlorvos emulsion or pyrethroid pesticides into the wormhole with syringe, and blocking the wormhole with soil.

Growth habits of jujube

The jujube tree grows in the mountains, hills or plains below 1700 meters above sea level. It is a temperature-loving fruit tree. The average annual temperature in the producing area is about 15 ℃. The temperature in the budding stage is 13-15 ℃, the temperature in the leaf-spreading stage is 17 ℃, the temperature in the flowering and fruiting stage is 22-25 ℃, and the temperature in the fruit-ripening stage is 18-22 ℃. Jujube has strong tolerance to drought and waterlogging, but it requires higher air humidity at flowering stage, otherwise it is disadvantageous to pollinate and set fruit. In addition, jujube has strong light preference, sensitive to light, strong adaptability to soil, barren and saline-alkali tolerance. But afraid of the wind, so we should pay attention to avoid the tuyere in the process of building the garden.

How to protect flowers and fruits in jujube trees

1. To restrain vegetative growth, adjust the contradiction between growth and fruit, and promote fruit setting, such measures include root cutting, coring, sprouting, branch thinning, nail opening, ring cutting, cutting, fertilizer and water management, and so on. it can regulate the contradiction between nutrient distribution and operation between tree vegetative growth and flowering and fruit, improve tree nutrition level, and make more nutrients needed for flowers and fruits.

2. Spraying water at flowering stage can increase the air humidity, and the air humidity during flowering period is not less than 60% to 70%, otherwise it will be affected. The effect of spraying water in the evening or morning is good, generally combined with foliar fertilizer spraying 0.3% 0.5% urea.

3. Release bees in jujube orchard and increase pollination medium. some jujube varieties are self-pollination and some are cross-pollination. Intra-variety pollination or inter-variety pollination can set fruit well, and the effect of increasing pollination media is good.

4. Spraying plant hormones and trace elements, mainly gibberellin, 2.4 Mel D, paclobutrazol, dwarf, B9, indolebutyric acid, indole acetic acid, acetic acid, borax, boric acid and so on.

Therefore, when planting jujube trees, fruit farmers should not blindly plant them. Before planting, they should first understand the growth habits of jujube trees. The most important thing is to understand the prevention and treatment of their respective diseases and insect pests, so as to avoid being in a hurry in the actual planting.