Comprehensive prevention and control of litchi pests and diseases

Lychee is a perennial fruit tree with a tall canopy and many major pests and diseases. Due to the high value of commodities, farmers attach great importance to the management of litchi. However, due to lack of prevention knowledge, frequent use of drugs, insufficient knowledge of pesticide application knowledge and side effects, blind use of drugs, abuse of pesticides, thus killing natural enemies, polluting the environment, and destroying the ecological balance of forest organisms. In many places, the cockroaches and cockroaches have been prevented, but some minor pests such as leaf mites, whiteflies, scale insects and mites have occurred in the past. Therefore, in the comprehensive prevention and control of litchi pests and diseases, it should be advocated "based on agricultural control, with biological control and application of high-efficiency, low-toxicity, low-residue pesticides as the main content, scientific use of drugs, coordination of biological defense and chemical defense relations, protection of natural enemies, play The comprehensive control measures that natural enemies naturally control the effects of various pests and control the pest populations below the level of economic loss are the future direction of litchi pest control. The specific measures are as follows:

1. Based on the agricultural control, after the fruit picking, the diseased branches and branches are cut off, and the fallen leaves and the scorpion worms are removed to damage the fruit, and the field is burned to reduce the source of pests and diseases. Rational fertilization to enhance the ability of plants to resist pests and diseases.

Years of practice have proved that timely control of winter shoots is not only conducive to the extraction of flower buds in the following year, but also control the growth and reproduction of cockroaches and mites on winter shoots, cut off suitable foods, and control pests in winter, reducing the number of times. The source of insects in early spring. In winter, the lychee canopy, branches, stem base and ground soil are sprayed with copper oxychloride or Bordeaux mixture to prevent Phytophthora capsici and plague overwintering bacteria, and to reduce pathogenic bacteria in early spring.

2. Prevention and control of litchi in different growth stages

(1) Early spring flower bud period: The focus of insect pests is lychee mites and mites. At the beginning of March each year, 90% of trichlorfon 800 times plus 20% dicofol can be mixed and sprayed once to eliminate lychee mites before spawning. The dragonfly breeds and expands on the spring shoots. In terms of diseases, such as more rainy days before flowering, it is conducive to the occurrence of Phytophthora mildew and anthrax. It can be sprayed with 600 times of mold or 600 times of spray, and the pests and diseases are controlled together. At this time, prevention and control should pay attention to the influence of pollinated insects and natural enemies, such as litchi trees tall,

Especially for large trees of 30-50 years or more, there are many lychee mites, and it is best to release the flat-bellied bees. Each tree is in early March every year, from the end of March to the beginning of April twice, each with 500 heads, which can prevent cockroaches. Like the egg stage, the effect is ideal.

(2) Fruit period: focus on the prevention and control of mites and downy mildew within 20 days before harvest, which is an important part of threatening yield. It should be based on the occurrence of this disease, such as 20 days before harvest. 10 days, each application of high-efficiency baidu 1500 times plus mold more than 600 times, mixed spray. In the whole fruit period, investigation and reporting of various pests and diseases should be done, and timely detection and timely use of drugs should be carried out. In the young fruit period, we must also strengthen the monitoring of pests such as the scales and do a good job in prevention and treatment.

(3) Autumn shoot period after fruit picking: The autumn shoot is the result of the next year. Protecting the autumn shoot is an important issue to ensure whether there are flowers and fruits in the next year. Therefore, after picking the fruit, it is necessary to trim the branches in time, cut off the pests and branches, and remove the dead leaves and weeds on the ground. Every time the autumn shoots are extracted, attention should be paid to the scales and leaf-rolling insects, and timely prevention and control should also pay attention to the anthrax. The disease occurs, protect the autumn shoots, and create good conditions for the next year's flowering results. At this time, the use of pyrethroid pesticides should be avoided as much as possible to avoid the occurrence of secondary pests.