Prevention and control of rose rust

First, the symptom of rose rust is the main disease of roses, which is common in all parts of southwest China, and the incidence is more serious in areas with warm seasons and winter rain and foggy seasons. According to the author's investigation for many years, the incidence rate is as high as 80% in some areas of our province. White flowers and purple roses were infected, causing leaves to fall off, affecting growth and flowering, and also harming many plants of the genus Rosa. The disease infected leaves, petioles, calyx and tender stems, and first appeared small yellow spots on the front. Or orange polyhedral spots, many apricot powdery substances appeared on the reverse side of the leaves in June and July, and the disease spots were yellow warts on the petioles and twigs. This is its "summer spore", spread by wind and rain. The pathogens are subphylum basidiomycetes, Puccinia, and Rose polyspore rust. The pathogens overwintered on the disease part and remnant leaves with winter spores. Second, prevention and control methods 1. Artificial control, timely removal of diseased buds, diseased leaves and concentrated burning, in order to reduce the spread of pathogens. two。 Strengthen cultivation management, increase the application of phosphorus and potassium fertilizer to enhance resistance, pay attention to ventilation, light transmission and drainage, in order to reduce the humidity of the surrounding environment and reduce the disease conditions. 3. Chemical control: spray 1 ∶ 1 ∶ 150 × 200 Bordeaux solution and Baume 0.3 degree stone sulfur mixture every two weeks from May to August. The following pesticides can also be used for spraying: 97% diuron sodium 250g 300x solution (50kg 100g soap powder per 100jin), 20% triadimefon (triadimefon) wettable powder 2000 times, 30% green Debao 30000g 400 times, 10% high water dispersible granules 30005000x, 25% Foxing EC 50008000x, 30% Teflin wettable powder 30005000x, etc.