1 The main diseases after flowering
1.1 Anthrax
Grape can be infected with anthracnose at the flowering stage, and it is susceptible to the disease under the conditions of heavy rainfall and high air humidity. After the fruit is infected, symptoms generally do not appear until the maturity stage. The closer the fruit is to maturity, the faster the disease occurs. Most of the small water-soaked light brown or purple spots appear in the middle and lower parts of the fruit, and then turn into dark brown or black. When the air is humid, orange-red sticky spots can be seen on the lesions. In severe cases, the lesions can extend to half or even the entire fruit surface, or several lesions are connected to cause fruit rot, and the rotten fruit is easy to fall off.
1.2 Powdery mildew
Generally, the disease starts from late May to early June, and the disease peaks from mid to late June to late July, and drought and alternating dry and wet weather are conducive to the occurrence of the disease. When new shoots, fruit stems and cobs are damaged, irregular patches appear on the initial surface and are covered with white powder, the cob and fruit stems become brittle, and the growth of shoots is blocked. When the fruit is damaged, the green patches appear first, the star-shaped pattern appears on the fruit surface, and a layer of white powder is covered on it.
1.3 White rot
White rot is the main disease that causes grape fruit to rot. The climatic conditions of high temperature and high humidity are the main factors for the occurrence and prevalence of the disease. From July to August, high temperature and rain, especially after storms or hail, are easy to cause white rot epidemics. The damage of fruit ear mostly occurs in the coloring stage, and the disease first starts from the ear near the ground, and produces light brown, water-soaked, and inconspicuous lesions on the cob and fruit stalk, and gradually spreads to the whole fruit. The onset of the fruit first turns light brown and soft rot at the base, then rapidly expands and causes the whole fruit to turn brown and rot.
1.4 Ulcer disease
In recent years, there have been aggravated fungal diseases. The symptoms of the fruit are in the fruit color change period. The cob appears black-brown lesions, the branches are ulcerated, and the downward development causes the fruit stem to dry up, causing the fruit to rot and fall off. Sometimes the fruit does not fall off and gradually dries up. shrink. Before and after flowering, low temperature and rainy weather or excessive humidity in the shed is conducive to disease, and plants with weak tree vigor are more susceptible to disease.
2 Prevention and control technology
2.1 Agricultural control
Strengthen the management of fertilizer and water, and regulate the indoor temperature and humidity of the facility shed. Excessive vegetative growth can easily cause the orchard to close. Avoid heavy application of nitrogen fertilizer in the later stage, and keep the orchard ventilated and light. Reasonably thin the flowers and fruits, establish a standard ear density, and make the tightness between the fruits moderate. Prune diseased leaves and branches in time and take them out of the garden for treatment to keep the garden clean.
2.2 Chemical control
Take 2 to 3 times of chemical control during the critical time after flowering and before bagging. 2,500-5,000 times of 42.4% oxazolidine·fluorinamide suspension agent, 4,000-6,000 times of 30% hexazole·azoxystrobin suspension agent, 1,500-3,000 times of 20% penthiopyrad suspension agent, 50% fluorine 2,000 to 3,000 times of cyclosporin suspending agent, 1,000 to 1,500 times of 40% gram bacteria and tebuconazole suspending agent, 800 to 1,300 times of 10% difenoconazole aqueous dispersible granules, 325 g/L 1,500-2,000 times of benzyl azoxystrobin suspending agent, 4,000-6,000 times of 40% myclobutanil wettable powder, 400 g/L chlorofluoroether-pyrazolate suspension agent of 1,500-2,000 times of suspending agent, etc. prevention.
3 Notes
Avoid using emulsifiable concentrate and powder pesticide formulations before bagging, so as not to affect the appearance of the fruit, carry out a prevention and control after fruit thinning, and then bag the fruit surface when it is air-dried. Use high-efficiency, low-toxicity, low-dose, and environment-friendly pharmaceuticals. The active ingredients with the same mechanism of action cannot be used more than twice in a row. Pay attention to the rotation use of pharmaceuticals and the safety interval, so as to ensure safe and reduced doses of medication, and ensure the quality and safety of agricultural products.
