How to treat flower powdery mildew?
How to treat flower powdery mildew.
First, the incidence law of flower powdery mildew: the pathogen overwintered on the diseased remains and buds with mycelium or conidia. In early spring, conidia spread by wind and rain, infecting leaves and shoots. Repeated infection occurred many times in the growing season, and the disease was more serious from April to June and from September to October. High temperature drying, excessive application of nitrogen fertilizer, over-close planting, lack of sunlight or poor ventilation are conducive to the occurrence of diseases. There were differences in resistance among varieties.
2. prevention and control methods of flower powdery mildew:
1. Fine pruning in early spring, cutting off diseased branches and leaves, and burning them in time.
2. Increase the application of phosphorus and potassium fertilizer and control nitrogen fertilizer.
3. Spray Baume 3-4 degree stone sulfur mixture, or Bordeaux liquid 1-1-1-2-1-1-2-1-100-200 before germination. At the initial stage of the disease, the shark can be sprayed with 80-1000 times of carbendazim, 80-1000 times of carbendazim wettable powder, or 1000 times of thiophanate methyl. When the disease is serious, spraying 2000-3000 times liquid can quickly control the disease.
① pruned carefully in early spring, cut off diseased branches and leaves, and burned them in time.
② increased application of phosphorus and potassium fertilizer and controlled nitrogen fertilizer.
The initial stage of ③ can be sprayed with 50% carbendazim wettable powder 800-1000 times, or 70% methyl topiramate 1000 times. Spray Baume 3-4 degree stone sulphur mixture, or Bordeaux liquid 1-1-1-1-12-100-200 before germination.