How to control the pests and diseases of walnut trees

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Precision agriculture is modern agriculture based on information and knowledge support. It is a knowledge-based agricultural management system. It is an important basis for accurate agricultural practice to quickly and efficiently collect information that accurately describes the spatial variables that affect crop growth. Pests and diseases are the main factors that restrict the production of crops and limit the improvement of quality, and the outbreak of crop diseases and insect pests occurs in a large area in a relatively short period of time, causing huge losses to agriculture. Today we first understand the effects of pests and diseases on walnut trees and how to manage them.

The damage to the walnut trees by pests is mainly stems and stems. Sapling trunk or collateral disease, disease spot early shuttle-shaped, dark gray water stains slightly swollen, hand-press flow with foamy liquid, diseased skin brown with distiller's grains taste, after the disease skin subsurface concave, lesions There are many small black spots scattered on the pathogen conidia. When the humidity is high, orange gums emerge from small black spots, which are the spore angles of pathogens. Spread of lesions caused by longitudinal crust out of black water. The trunk of the tree was infected at the beginning of the disease. The symptoms were hidden in the phloem and the appearance was not easy to see. When the symptoms were seen, the subcutaneous disease also expanded to more than 20-30cm, and there was a thick black water that often stuck on the trunk. Branches become infected: one is chlorosis, the cortex is filled with water and the xylem is separated, causing branches to dry and black spots on it. The other kind of diseased spot appeared from the cut slash and spreads downward along the tip or to another branch, forming a dry tip after a week.

Tianniu is also known as Tiegu Niu, Iron Barb, and is one of the main insects that harm walnut trees. The walnut production areas in Sichuan are distributed. The main damage to the branches, the damage rate of 95% in areas with serious damage. The main branch of the victim’s tree died, and some of the trunks died of the whole plant.

The victim’s symptom is that the cortex in the victim area is slightly cracked, and a large amount of dung was discharged from the wormhole. After the damage, the cortex is cracked, and there are fewer worms in the xylem than wood moths. Adult emergence holes are mostly in the upper part, showing a large round hole. The number of generations of Cloudbill Tendai varies from place to place, and the overwintering state is also different. It usually takes 1 generation and 3 years in 2 years. Adults or larvae lived in the trunk during the winter and began their activities in late April. May was the adult emergence period and the middle and late June was the peak of spawning. The larva is pale yellow and not enough. Adult dark brown or auburn, with suspended animation and phototaxis habits.

The prevention and control method is to brush the trunk with walnut and fruit-curing spirit I before winter or spawning period; clean the wood in the insect eyes with iron wire at the place where there is insect eyes, and then inject the walnut drug fruit spirit I into the wormhole with a syringe. Seal the hole with mud. The insecticidal effect is good; using the adult phototaxis and dead-dead habits, the light lures to kill under the tree at night. When the leaves and twigs are frequently observed during the day and young shoots are found to be bitten and fresh, adults can be caught nearby. After spawning by adults, they are frequently inspected and found that there are notches in the hatching of eggs, and hammering with hammers can eliminate eggs and newly hatched larvae. When the larvae enter the tree trunk, they can be marked with insect feces. The tips of the larvae are made into small hooks with fine iron wires, inserted from the wormholes, and larvae are killed.

Prevention methods (1) Attention should be paid to the removal of diseased fruits and diseased branches and leaves, concentrated deep-buried or burned, which can reduce the source of bacteria.
(2) Selection of disease-resistant varieties. When planting Xinjiang walnut, the row spacing should be appropriate, not too dense and well ventilated.
(3) Strengthen the management of the walnut garden, timely cut off diseased branches, deeply buried or burned to reduce the source of bacteria. Increase organic fertilizers, increase tree vigor, and increase resistance to disease. Or, with the advancement of science, pest and disease information collection systems can also be used to collect information on pests and diseases in a timely manner.
(4) The north pays attention to the cold and prevents the tree from freezing. Timely control of walnut tree pests to avoid insect damage or other mechanical injuries.
(5) The main disease should be promptly scraped off the diseased part and sterilized with 1% copper sulphate or 40% thiophene wettable powder 50 times and smeared with coal tar. During the period from June to July, the diseased fruit was removed and sprayed in 1:2:200 times Bordeaux mixture in a timely manner. The heavy-damaged walnut garden was sprayed with 25% carbon tetrachloride wettable powder 500 times or 50% to make 100 grams wetability after flowering. Powder 800 times liquid, 50% protection power wettable powder 1000 times, every 10 to 15 days 1 time, continuous control of 2 or 3 times.

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