Prevention and control techniques of common diseases and insect pests in orchids

In the process of orchid cultivation, orchids are often harmed by diseases and insect pests, which not only reduces the ornamental value, but even dies.

1. Anthrax. The disease is the most common disease of orchids, which mainly harms the leaves. Black dots are produced on the disease spots in the later stage, which eventually leads to withered and yellow leaves. The disease often occurs in May-June, in the Meiyu season or in the years with more autumn rain or typhoons from September to October. Prevention and treatment: ① cut off the disease and burn the remains in time. ② improved the way it was watered by slowly injecting water from the edge of the flowerpot. After the new leaves of ③ sprouted in winter, spray Bordeaux liquid (1JV 140) 1 Mel twice, spray 50% carbendazim 500 Mel 600 times liquid at the initial stage of the disease, and at the same time strengthen ventilation and light transmission to avoid foliar spray.

2. Leaf blight. The leaves of orchids were mainly damaged by small reddish-brown spots at the beginning, and then rapidly expanded into oval or round black-brown spots, with more disease spots, and the leaf tissue between the disease spots turned green and turned yellow and withered. Prevention and cure method: ① removes diseased leaves and concentrated burning of diseased remains. ② should pay attention to ventilation and light transmission, prevent excessive watering, and avoid direct spraying of plants. ③ can be sprayed with 50% topiramate 600 mol 800 times solution. Once every 10 days or so, spray 3 Murray for 4 times.

3. White silk disease. One of the major diseases of the genus Cymbidium, caused by fungi. It is easy to occur in the high temperature and rainy season, which often occurs in May and June, with the peak of the disease in July and August. Prevention and treatment methods: ① timely removal of diseased leaves, diseased plants, diseased points, can be mixed with lime disinfection; before setting the plant, wet the basin soil with 1000 times solution of soil seedling dewatering agent. In the early stage of ②, 500 times of chlorothalonil can be used to spray leaves and roots.

4. Scale insects. Shield scale and pink scale are the most common. The occurrence period is from April to October, and it occurs occasionally in winter. Its fecundity is extremely strong. Many generations can occur in a year and generations overlap, especially from May to October. Prevention and treatment: when a small amount of ① occurs, you can use a soft brush to remove it, then rinse it with water. When there is more ②, 1000 times of the emulsion can be sprayed during the peak incubation period. When spraying, both the front and back of the leaves should be sprayed, and the leaves should be sprayed 4 times in a row, each time with an interval of 5 Murray for 7 days, then it will be basically extinct.

5. The red spider has strong reproductive ability and serious harm, and it is easy to occur in the high temperature period from June to August.

Prevention and control methods: the number of ① is small, can be removed with a brush or a small brush. Most of ② were killed with 1000 times of dicofol. ③ local method can ignite mosquito-repellent incense, put it in the basin of diseased plant, and cover it with plastic bag. After smoking for 1 hour, both eggs and adults are killed, and the plant is not affected.