So, what are the common diseases and pests of lemon? How to prevent it? What preventive measures are there? Let's have a look.
What are the common diseases and insect pests of lemon? 1. Symptoms of lemon canker: It mainly damages branches, leaves and fruits.
At first, the diseased leaves were yellow oily spots on the needles, and later they expanded into circular spots, and the diseased spots on both sides of the leaves were raised. The central depression is cracked into a gray-brown rotten mouth shape with yellow halo around it. The diseased leaves are not deformed and often fall early.
The disease is caused by bacteria, mainly transmitted by rain and insects, and easily induced by high temperature and humidity, typhoons and rainy days.
2. Symptoms of lemon resin disease: lemon resin disease, also known as gummosis, damages trunks, leaves and fruits, as well as damaged trunks. Bark is reddish brown, sunken, soft in tissue, secretes smelly mucus, leaves, shoots and young fruits are damaged, and the surface appears dark brown protrusions.
The disease is caused by fungi, and the plants of weak trees, dead trees and pest trees are seriously ill.
3. Symptoms of lemon scab: Lemon scab is mainly caused by fungi. With the help of common diseases spread by wind, rain and insects, rainy and humid weather is an important condition.
It mainly harms new shoots, young leaves, young fruits and young leaves, with oil spots, funnel-shaped dorsal protrusion and leaf depression. In severe cases, the treetops are shortened, the leaves are twisted and deformed, and many tumor-like processes appear in fruit symptoms.
4. Symptoms of the lemon red spider: The red spider takes adults and nymphs outside the canopy, pierces the epidermis of leaves, tender shoots and fruits with mouthparts, and sucks juice. There are many dense white spots on the surface of the damaged leaves, and the leaves lose their green and luster. In severe cases, the whole leaf turns gray, causing deciduous leaves.
5. Disease symptoms of lemon leaf miner: Leaf miner is an important pest of lemon seedlings, young trees and adults. It harms new shoots and young leaves with larvae, and feeds on mesophyll under the epidermis of potential young leaves, forming a silver-white curved tunnel with black lines in the center. With the twists and turns of the wormway, the new leaves contract and harden, and the leaves fall off, and the new shoots are serious in spring, summer and autumn.
Control methods of common diseases and pests of lemon 1 and lemon canker ① Strengthen field management, do a good job in clearing gardens in winter, collect fallen leaves, fallen fruits and dead branches, and burn them centrally to reduce the source of disease infection.
(2) When the new shoots grow to 4-5 cm, spray streptomycin 600-800PPm, Bronze Master 1000- 1200 times, Shigao 1200- 1500 times and kill 600-800 times.
2, lemon resin disease ① Rational fertilization, strengthening management, and improving the disease resistance of fruit trees.
(2) Scrape the diseased parts of the trunk, and apply 0/00 times of Royal Copper/KLOC-and 300-400 times of 70% Tobuzine.
3, lemon scab ① When clearing the garden in winter, trim the diseased leaves, diseased branches and diseased fruits and take them out of the garden for treatment.
② Protective fungicides, such as pyraclostrobin, difenoconazole, mancozeb, methyl acetate and propineb, are mainly used to control the germination of spring shoots and young fruits before fruiting.
4. Lemon Red Spider ① Strengthen fertilizer and water management, improve the resilience of trees, prune diseased branches and dead branches, keep the orchard ventilated and transparent, and timely drain and irrigate to reduce the harm of mites.
(2) Combined with clearing the garden in winter, spraying 1~3 degree sulfur mixture to eliminate overwintering adults, eggs and larvae.
③ Use 5% Nisolone 3000 times solution, 20% clofentezine 2000 times solution, 15% pyridaben 2000 times solution and 5% avermectin 3000 times solution for control.
5. Lemon leaf miner ① Shake branches in sunny morning or before the dew is dry after rain, and shake dead adults to the ground to kill them.
(2) Collect all the dead leaves in the garden in time for centralized burning in winter, cultivate garden soil in winter, and reduce pupation larvae.
(3) Use pesticides compounded with systemic drugs in peak period, preferably long-lasting drugs such as biological pesticides, chlorantraniliprole and thiamethoxam, preferably long-acting dosage forms such as microcapsules.
The above is the information of lemon diseases and insect pests provided by Bian Xiao. I hope the above information can help you.