Control of common diseases and insect pests of Ligustrum lucidum

The common diseases of Ligustrum lucidum are: leaf spot disease, ring disease, coal pollution disease and so on. The main pests are: shell insects, grubs and so on.

Brown spot disease

Brown spot is the most serious leaf spot disease of Ligustrum lucidum, which is caused by pathogenic fungi. In the early stage of the disease, there are small brown spots on the leaves, with purplish red halos around them, and black mildew can be seen on the spots. As the temperature rises, sometimes several disease spots are connected, and finally the leaves scorch and fall off. The most suitable temperature range for the growth of the pathogen was 25 ℃ to 30 ℃, and the optimum temperature for spore germination was 18 ℃ to 27 ℃. Under the condition of suitable temperature and high humidity, the spores could germinate in a few hours. After entering the rainy season, if there are plants with dense planting and poor ventilation and light transmission, a relatively stable environment with high humidity and suitable temperature is formed among the plants, which is very beneficial to the germination and invasion of spores, and the bacteria can be infected repeatedly without paying attention to it. it may cause the disease to occur in a large area. When the disease occurs, a large number of leaves fall off, seriously affecting the landscape. Can spray carbendazim 1000 times liquid or Japanese 1200 times liquid.

Coal pollution disease

The occurrence of coal fouling disease is mainly caused by the secretion of scale insects. After being damaged, the plants, leaves and branches are covered with black coal dust, the photosynthesis of leaves is inhibited, and the branches, stems and leaves are harmful to the whole plant. The control method should be to treat both diseases and insect pests: spraying 50% bacillus special wettable powder 600 times plus 40% omethoate EC 800 times.

Dendrolimus koningii

Also known as mulberry pink scale. The female adult is about 5 mm long and 3 mm wide, the body is flat and oval, pink, and the body surface is covered with white wax powder; the nymph is oval, flat and yellowish, and the body surface is also covered with white wax powder; the egg is oval, yellowish, and the oocysts are white cotton floc. Dozens of tablets are gathered into chunks. There are three generations a year, the first generation nymph is in mid-late May, the second generation is in mid-late July, and the third generation is from late August to early September. Prick and suck plant juice, causing branches and leaves to lose water and wilt, and in serious cases, the whole plant shrinks and dies. Can also induce coal fouling disease.

In autumn and winter, clean the dead branches and burn the fallen leaves to kill the overwintering eggs or females. The effect of drug control is good in the peak egg hatching period or the first instar nymph stage. If the 1000-1500 times solution of chlorpyrifos is sprayed every 5 to 7 days, it can be eradicated after 2 to 3 consecutive times. When spraying, pay attention to spraying the whole plant (do not only spray the leaves each time, but shoot the gun through the surface leaves on the branches), so as to achieve a good control effect.

Grub

Grubs harm the roots of Ligustrum lucidum seedlings planted for more than two years, bite capillary roots and main root epidermis, and even root system necrosis and decay, sometimes resulting in only surface capillaries and poor water absorption capacity. After the root system is damaged, once the high temperature weather is encountered, the whole plant wilts, and in serious cases, it will dry up and die.

When poison bait is used during the harm period, 0.5 kg of phoxim, 0.5 kg of water and 15 kg of half-cooked seeds can be mixed and spread evenly on the seedbed at night during the harmful period. Or 1000 times phoxim irrigation root, phoxim photolysis is stronger, should be applied or buried in the soil at night.

The prevention and control of diseases and insect pests of Ligustrum lucidum should not only strengthen plant maintenance and management, rational fertilization, scientific watering, enhance plant growth potential and disease resistance and insect resistance. We should also pay attention to the following points: adhere to "disease treatment, disease-free prevention" for diseases. At the same time, try not to prune strongly during the growing period. if you want to be neat and consistent, you must prune. After pruning, spray protective solution such as 1500 times mancozeb or 1000 times carbendazim every 5 to 7 days. Spray 3 to 4 times in a row. In the season of high temperature and humidity, fungicides should also be sprayed once a week to prevent diseases; for pests combined with winter pruning to clean up residual branches and withered leaves, kill adults, and avoid a large number of nymphs in the coming spring.