At the onset of the disease, the whole or most of the leaves turn brown and rotten, or the base of the stems and vines and tender nodes show dark green water stains. The plant gradually became soft and atrophic, and the branches and leaves above the diseased part withered. The disease is often caused by the presence of bacteria in the soil, or the high humidity of the air and the sultry environment. Once the disease occurs, it will spread rapidly.
Pull out the diseased plants in time and control watering properly.
Plant disease-free plants and disinfect the soil before planting. At ordinary times, it is necessary to strengthen maintenance, pay attention to ventilation and light transmission, and timely block rain when it rains, so as to prevent basin soil from being wet and moisture retention.
In the early stage of the disease, spray or irrigate 800 times of 25% metalaxyl wettable powder or 58% metalaxyl. 600 times of manganese zinc wettable powder. There are many options, just go to the market.
At the onset of the disease, the edge of the leaf produces water stained brown or black spots. In severe cases, the spots may occupy most or the whole leaf, and in humid conditions, grey mould layer will be produced.
Cultivate with disease-free new soil, control watering, and do not apply too much nitrogen.
Remove the diseased leaves in time and burn them. At the onset of the disease, 75% chlorothalonil 500 fold solution was sprayed. Once every 10 days, 2-3 times in a row.
In the early stage, only a small round dark spot appeared on the leaf surface, with oil stained halo. After enlargement, it is black, some of them are polygonal, and occasionally there are ulcer spots on petioles. The leaf spot disease is serious, infectious, easy to relapse, and difficult to cure.
To choose a disease-free mother plant for reproduction, we must recognize the store when we buy it. Don't buy back a basin of diseased plants. We can't raise them any more.
In the early stage of the disease, streptomycin sulfate 3000 times solution or 12% green copper emulsion 600 times solution and 20% Long Ke bacteria suspension 500 times solution were sprayed.
Many flower friends have seen the scale insects. It seems that there will be many small white spots on the plants far away, which will affect the beauty. However, in the later stage, the scale insects will play havoc on the leaves, causing the leaves to turn yellow, the plants to wilt, and even the whole plants to die. The scale insects leave wounds on the leaves, and are easy to be infected by bacteria and cause diseases.
In the early stage, the pests are less and can be scraped off manually. In the later stage, if a large area of disease is found, 40% Omethoate emulsion can be sprayed 800 times.
