After potato infection, the early leaves became weak, the top leaves turned back slightly, and then the whole plant wilted, browned and died. From the ground to the infected underground roots, the cortex tissue of potato pieces is rotten and easy to peel off, and the lateral roots are locally browned and necrotic, so the diseased plants are easy to pull out. There are many small gray spots on the stem, and many black granular sclerotia grow in the cavity at the base of the stem.
Potato anthracnose is mainly caused by anthracnose. Even if potatoes have never been planted in the plot, if the seed potatoes carry bacteria, they may cause diseases after sowing. Even if only a part of potatoes in a field are infected with anthrax, hyphae will produce spores, which will spread through rain splashing, and healthy potatoes will also be infected with anthrax when they are stained with spores containing anthrax.
Dealing with anthrax is not impossible;
1. Eliminate the root cause of the disease, carefully select seed potatoes, and ensure that all potatoes planted in the field are disease-free. Before sowing, seed potatoes can be soaked in 600 times of 70% thiophanate methyl wettable powder, and the germs can be killed in about 5 ~ 10 minutes.
2. Strict management after training. Try to choose fertile soil for planting. If there was potato anthracnose in the field last year, try not to plant potatoes again this year. In addition to normal chemical fertilizers, try to increase organic base fertilizer and increase drainage channels to avoid high temperature, high humidity and stagnant water in the field, minimize the survival of anthrax bacteria and reduce the spread of bacteria through rain.
3. Timely treatment at the early stage of the disease can spray targeted drugs, and farmers should pay attention to reasonable dosage to avoid other injuries to potato plants. For example, 400 times of 40% polysulfide suspension, 600 times of 25% carbomer wettable powder, 2000 times of 30% emulsifiable concentrate, 400 times of 50% mirex wettable powder, or 500 times of 5% Tianan aqueous solution can be selected, and the disease can be basically controlled by spraying/kloc-0 once a week for 2-3 times in a row.