Control of anthracnose in growing peach trees

With the adjustment of agricultural industrial structure, the planting area of peach trees in our county is constantly expanding. due to the influence of climatic conditions, varieties, management and other factors, peach anthracnose occurs seriously and has a great impact on the yield and quality of peach trees. Effective control of anthracnose is very important to improve yield and efficiency.

First, harmful symptoms. The disease is mainly harmful to fruits, but also to leaves and shoots. The young fruit is damaged by light brown water stains at first, and then round or oval with fruit expansion, reddish brown, sunken in the center; when the climate is humid, the young fruit stops growing after the disease grows, and the early fruit drop is formed; when the climate is dry, stiff fruit is formed. The disease spot of mature fruit showed obvious concentric ring shrinkage. Leaf blade disease spot round or irregular, light brown. The boundary between disease and health is obvious, and in the later stage, the disease spot is grayish brown, dry and shedding, resulting in perforation. The disease spot on the new shoot is long oval, dark brown, slightly sunken. The leaves on the diseased shoots are curly, and when they are serious, the shoots often die.

Second, the pathogen and the law of disease. Peach anthracnose is a fungus of the genus Colletotrichum. The bacteria overwintered with hyphae in diseased branches and diseased fruits, and encountered suitable temperature and humidity conditions the following year, that is, when the average temperature reached 10-12 ℃ and the relative humidity reached more than 80%, spores began to form and spread by wind, rain and insects to form the first infection. The disease has been damaged for a long time and can be infected in the whole growth period of peach. High humidity is the main cause of the occurrence and epidemic of the disease. The flowering and young fruit stage is cold and rainy, the fruit ripening stage is warm, cloudy and foggy, high humidity is conducive to the disease. The peach orchard with extensive soil viscosity, poor drainage, excessive nitrogen application and closed canopy caused serious disease.

III. Prevention and control techniques

1. Orchard planning: do not build a garden in low-lying, poorly drained clayey soil areas, ridge and transplant, and pay attention to the selection of varieties.

2. Strengthen cultivation management: apply more organic fertilizer and phosphorus and potassium fertilizer, timely summer pruning, improve tree structure, ventilation and light transmission. Combined with winter pruning, the withered branches, stiff fruit and ground fruit on the tree can be removed, burned or buried deeply, and the source of infection can be reduced.

3. Chemical control. Spray Baume 3-4 degrees stone sulfur mixture with 80% pentachlorophenol sodium 200-300 times before germination, or 1-1-100 Bordeaux solution to eradicate the source of the disease. Spray the medicine once before flowering. Spray the medicine every 10 days or so after falling flowers, for a total of 3-4 times. The medicament can be treated with 1000 times of 70% methyl topiramate wettable powder, 80% anthrax Fumei wettable powder, 50% carbendazim wettable powder, 50% carbendazim 400,500 times or 50% carbendazim 1000 times. The potions had better be used alternately.