How to treat rose disease

The cultivation of roses has a long history. There are stories about roses in myths and legends of various countries. In China, roses are regarded as the symbol of assassins and chivalry because of their prickly branches. In the West, roses are regarded as a symbol of strict secrecy. In addition, different colors of roses also have their own meaning or love language. So what diseases are there to pay attention to when planting roses? How to treat the disease?

I. Disease control of roses

The common diseases of roses are powdery mildew, downy mildew, branch blight, black spot, rust and other diseases. when the disease occurs, the disease should be determined according to the specific disease symptoms. generally, Orick-Liangguoan plus Wofengsu plus garlic oil can be sprayed, but the specific symptoms still need specific analysis.

Rose powdery mildew mostly occurs from late autumn to early spring and is easy to occur when the temperature difference between day and night is large and the humidity is high. In general, young leaves are infected, and other old leaves, flower stems and even branches are generally infected. When infected, the leaves show protuberance, the color of the convex part becomes light and white powder, the leaves form uneven and gradually curl up, the bacteria spread, and the whole back of the leaf is covered with a layer of gray mold. The control method is to spray regularly with 600 times of nitrilazole or 800 times of chlorothalonil, spray once every 7-10 days, and cut off the diseased branches and leaves as soon as possible to reduce the chance of retransmission.

Downy mildew mainly harms leaves, shoots, stems, pedicels and petals. The symptoms are as follows: first infect the growing point, the leaves turn purple to brown-black, the infected leaves appear irregular spots at first, then wither or fall off gradually, and the diseased shoots dry up. Similar spots appeared in flowers, pedicels and petals infected with disease. When the humidity is high, the gray-white mildew layer is easy to appear in each disease site. The prevention and control method is to spray 72% Kroe in time for the first attack, and it is best to select disease-resistant varieties when planting roses.

At the beginning of branch blight, red or purple spots appeared in the leaves, and then gradually expanded into disease spots, extending to the stem, grayish brown in the middle and reddish brown on the edge, which would lead to plant death when serious. During the treatment, the diseased branches should be cut off from the plant and sprayed with carbendazim wettable powder or carbendazim wettable powder diluted 600 times.

Black spot disease is the most common disease in rose cultivation, which is the most serious in the period of high temperature and humidity. It occurs in leaves, petioles and stems. When the plant is infected, black round disease spots appear on the leaves, especially the mature leaves close to the ground suffer the most. The diseased leaves will gradually yellowing and fall off. When the disease is serious, most of the leaves of the whole plant fall off, unable to carry out photosynthesis, resulting in poor growth. After discovery, use Olik-Liangguoan plus Vofengsu plus garlic oil spray.

Rose rust is one of the most important diseases of roses, which is common. The disease causes early defoliation, weakens the growth potential, affects the ornamental effect and reduces the yield of flowers. The main symptoms are yellow disease spots on the upper surface of new buds, stems and petioles, or chlorosis on the front of the leaves, orange-red blisters on the front of the leaves, orange-red on the back of the leaves, dark brown-red on the back, and finally a small pile of black powder. The main treatment is spraying 20% triadimefon EC 1500 times, or 40% DuPont Xinxing EC 9000 times, or 2% 120 antimycin 100 times 200 times, and so on. About once in 10 days.

The above is about the main symptoms of roses, in the maintenance of roses, we should pay attention to observation, timely determine the disease, and take targeted measures for treatment.