Plant growth process often encounter the invasion of disease, leading to a variety of problems, chrysanthemum leaves are also caused by the disease caused by the black spot.
Conidia chrysanthema damaged the leaves of chrysanthemum and caused them to turn black. In the early stage of the disease, the leaves of chrysanthemum will show green or purple brown spots, which are different in shape, round, oval or even irregular. Its diameter is 5 to 10 mm, very fine, the size and color of the spots are related to the variety of chrysanthemum
Many small dots gather together to form large spots. At the end of the disease, the color of the spots will also become light gray, giving birth to a lot of small dots that are not obvious. The leaves begin to decadent from the bottom to the top, but they will not fall off. When the disease is serious, there are only two or three intact green leaves left on a chrysanthemum.
1. First of all, if you find the black leaves, you should remove them immediately. If it's winter, you should destroy the sick leaves. If it's cloudy or rainy, don't water or reduce the amount of water. Don't drench the flowers. Don't let the flowerpot be too wet. Every year, you should replace it with new flower soil.
2. To control the fertilizer, the nitrogen, phosphorus and potassium fertilizer should be allocated properly, and the flowers should not grow violently. If there is too much water in the basin, it should be discharged in time, so that the flowers will thrive and develop, and enhance the disease resistance and immunity.
3. During this period, you can spray the solution, and you can go to the market to buy 75% bactericide 600-800 times solution, 65% zincic 500-600 times solution, and 1% Bordeaux solution. Spray once every seven to ten days, only three to four times, you can reduce the survival rate of bacteria.
4. When purchasing chrysanthemum, it's better to select varieties with strong disease resistance, turn over soil and change soil frequently, add sand and nutrient soil into the soil, and wash flowerpot, plant and flower soil frequently. If you want to transplant, you should choose the branches with no pathological changes.
