The latest course on the techniques and methods of pest control in citrus

Citrus belongs to Rutaceae. It likes warm and humid climate. During the growth and development of citrus, due to the influence of harmful organisms or bad environmental conditions exceeding its adaptability, its normal growth and development are inhibited, metabolism changes, resulting in low yield, poor quality and even death. This brings great loss to the economic value of citrus and seriously affects the economic income of growers. Therefore, A clear understanding of the main citrus diseases and insect pests and effective measures to prevent and control them is the biggest harvest for growers. Let's take a look at citrus disease and insect pest control techniques below!

citrus huanglongbing

[Harm symptoms] Citrus yellow shoot disease, also known as yellow shoot disease, is a disease of domestic plant quarantine object. Seedlings and young trees die within 1~2 years after the disease, and adult trees lose their fruiting ability within 2~3 years after the disease. Its symptoms in the early performance of a few new shoots on individual plants disease, in the thick green crown mixed with a small number of yellow shoots, commonly known as inserted golden flowers or chicken yellow. The leaf quality on the diseased shoot is hard and brittle, the mesophyll turns yellow from the base of the leaf while the lateral veins of the main vein remain green, showing a mottled shape with yellow and green alternating, the veins are swollen, local cork cracking or the whole leaf is uniformly yellowed.

[Prevention and control technology] ① Strict quarantine, prohibit the introduction of seedlings and scions from disease areas in new areas and non-disease areas. (2) Cultivate disease-free seedlings and establish disease-free nurseries. The locations should be selected in areas without Huanglong disease and citrus psyllid occurrence, and virus-free seedlings should be selected. (3) pest control, timely control of vector citrus psyllid. 4. Excavate diseased plants, strengthen inspection and deal with diseased plants in time.

citrus canker

[Harm symptoms] Citrus canker disease is the object of plant quarantine at home and abroad. Seedling and young tree are seriously damaged, resulting in dead leaves, weak tree vigor, light fruit damage with disease scar, reduced quality, heavy fruit drop and reduced yield. The disease damages leaves, branches and fruits. At the beginning, the spots were pinhead size, yellow, water-soaked, and then enlarged into nearly circular spots, raised on both sides of the leaves, cork, rough surface, grayish brown, crater-like cracking.

[Control technology] ① Strictly implement quarantine, soak the introduced seedlings and scions with 0.3% ferrous sulfate for 10 minutes. (2) Strengthen cultivation management, pruning and clearing garden in winter. Do a good job of bud control to reduce the incidence. Rational fertilization, fertilizer control shoots. (3) spraying to protect shoots and fruits, spraying 77% copper hydroxide wettable powder, 800 - 1000 times solution of 30% copper oxychloride suspension, 1000 - 1500 times solution of 20% dichloroisocyanurate A wettable powder or 1000 - 1500 times solution of 20% quinoxone wettable powder.

citrus scab

[Harm symptoms] Citrus scab mainly damages leaves, shoots and fruits, causing deciduous leaves and fruit drops. The unfallen diseased fruit is small and abnormal, the quality deteriorates, and the injured new shoots grow poorly. The disease can only infect young tissues of leaves, shoots and fruit fields. The affected leaves initially appear as water-soaked dots, then gradually expand, wax yellow to brown, 0.3~2.0mm in diameter, cork.

[Prevention and control technology] ① Seedling quarantine, new garden from other places to introduce seedlings and scions, quarantine. Scions and seedlings from other places can be soaked in 800 times solution of 50% benomyl WP and 800 times solution of 40% triadimefon carbendazim WP for 30 minutes. (2) Strengthen cultivation management, combine pruning in winter, cut off diseased branches and leaves, collect branches and leaves on the ground and burn them together, and spray spray medicine under trees immediately for prevention. Strengthen fertilizer and water management, promote shoot tidiness, shorten young fruit tender period, reduce the opportunity of pathogen infection. (3) Chemical spray control, protect tender shoots and young fruits. 30% copper oxychloride suspension 600 times solution, 40% triadimefon carbendazim WP 800 times solution or 50% prochloraz manganese complex 1000 times solution spray can be selected.

citrus anthracnose

[Harm symptoms] Citrus anthracnose often causes a large number of leaves, dead shoots and fruit drops of citrus trees, resulting in weakening of trees, decline of products and quality, and even death of branches and plants.

[Prevention and control techniques] ① Strengthen cultivation management, deep ploughing and soil improvement to avoid partial application of nitrogen fertilizer, increase application of organic fertilizer and phosphorus fertilizer and potassium fertilizer, timely drainage and irrigation, and do a good job in freezing prevention and other diseases and insect prevention. 2. Clear the garden in winter, cut off dead leaves and dead fruits, remove fallen leaves and diseased fruits on the ground, and burn them intensively or bury them deeply. (3) Chemical spraying control: spraying in spring, summer and autumn shoot tender leaf stage, young fruit stage and fruit expansion stage, spraying 25% prochloraz EC, 24% Niconazole SC, 43% Mancozeb SC 1000 times or 25% Bromocyanil EC 500~800 times.