In the beginning, there will be purple brown to brown grains on the leaves, and purple to black stripe spots on the twigs and pedicels. In serious cases, the whole leaf of the lower part of the plant will fall off, leaving only a few new leaves.
Remove the diseased leaves in time, trim them in winter, remove the pathogens left on the diseased stems, and do not water them at night. When sprouting in early spring, you can spray the stone sulfur mixture. After sprouting, you can spray the Syngenta huile, national light leaf disease or chlorothalonil every ten days. If the disease is about to shorten to one week.
Infected with the disease, the leaves will shrink, curl, the surface will be covered with white powder.
Prune properly, pay attention to ventilation and light, and do not apply nitrogen fertilizer for fertilization, so as to keep the plant healthy and strong. At the beginning of the disease, you can spray fungicides such as Triadimefon, Guoguang black and white disease or tolbutine methyl, almost once a week, two or three times in a row.
At the beginning, the back of the lower leaves will appear irregular spots of chlorosis, and full of frosty mildew layer, and later will become dark purple to brown, and the spots will gradually become burning from polygonal.
Pay attention to ventilation, plants should not be too dense, can spray 70% Guoguang mancozeb, chlorothalonil and other chemicals, spray once every 7 to 10 days, 2-3 times in a row.
Rust leaf disease will damage rose buds, leaves, branches, flowers, etc., mainly leaves, the most obvious symptom is to appear like rust powder particles.
After discovery, it should be removed in time. We can alternately use Guoguang black and white disease, 70% Guoguang mancozeb, chlorothalonil, etc.
Plant near the surface of the root neck will appear disease, stem cortex will fade at first, then will expand into irregular black spots, the edge will dry.
The breeding environment should not be too wet, and the disease branches should be removed in time. You can spray agricultural streptomycin or likujing, or spray 43% formaldehyde 40 times solution to the surface.
This kind of disease often occurs in the cut or grafting of pruned branches. At the initial stage, there will be purple spots, which will gradually expand. In the middle, there will be light brown, and the edge is purple red, which is irregular. At the later stage, the spots will crack and produce small black brown spots. When the disease is serious, it will circle around the branches, and the disease department will die or even the whole plant will die.
Pruning is best carried out in sunny days, and sulfur powder is applied to the cutting mouth. Cut off the diseased branches in time. Best spray 75% chlorothalonil WP 500-800 times.
The above is the rose disease and control of all the content, I hope to help you.
