Control of powdery mildew of cut rose

Powdery mildew is the most common disease in rose leaves. Prevention should be given priority to and prevention should be combined to achieve substantial results.

The methods of prevention are:

1. Before the plant germination in early spring, a 600-fold solution of carbendazim wettable powder was sprayed to kill overwintering bacteria.

two。 After spreading leaves in the following spring, rose plants were sprayed with carbendazim wettable powder 1000 times every other month for 3 to 4 times to consolidate the preventive effect, or the same amount of Bordeaux solution was sprayed every other half month for 3 to 4 times in a row, which could form a good protective film on the leaves of rose to prevent the invasion of spores.

3. Using 27% high-fat membrane emulsion 50 to 100 grams, adding 7 liters of water before or during the onset of the disease, evenly sprayed on both sides of the leaves, sprayed once every other week for 2 to 3 times, can form a transparent and breathable protective film, which can not only prevent the invasion of pathogenic spores, but also does not affect the photosynthesis and respiration of leaves. In addition, the cultivation of cut rose in greenhouse should increase ventilation, give sufficient light and increase plant resistance, which can significantly reduce the occurrence of powdery mildew; it is also very important to avoid excessive nitrogen fertilizer and properly increase the application of phosphorus and potassium fertilizer. it is also very important to prune and burn susceptible branches and leaves in early spring.

Treatment:

1. During the disease-free period, use 40% polysulfide suspension (a broad-spectrum fungicide made by a mixture of carbendazim and sulfur) 15 to 20 grams, add 7.5 to 10 liters of water to spray the leaves, spray once every 7 to 10 days, 2 to 3 times in a row, the effect is quite good.

two。 To prevent and cure with fluoxazole, the first time is sprayed at the initial stage of the disease, and the second time is sprayed at an interval of 10 days. it is generally used to wash the exposed parts such as face, hands and feet immediately after application, and gargle. Do not pour the remaining pesticides into paddy fields, rivers or fish ponds, so as not to cause harm to people and animals; it is the first choice for the treatment of powdery mildew.

3. During the growing period, 50% methyl topiramate 1500 times solution, 20% Fanling EC 3000 times solution, 50% benzoate wettable powder 1000 times solution were selected, and plants were sprayed once a week for 2 to 3 times in a row, which also had a good control effect.