What about white spots on chrysanthemum leaves?

1. Powdery mildew

1. Reason

This disease is caused by powdery mildew. The disease occurs in open fields in the south and in greenhouses in the north, and the bacteria spend the winter in the soil, in places with high humidity and low light, and where there is a great difference in temperature between day and night with poor ventilation. If we pour too much water on it, or if the plants are too dense or if drought occurs, the disease will be more serious. In the early stages of the disease, there are more yellow and white spots on the leaves, which are located on the front of the leaves, and other parts of it are also susceptible to infection and can be fatal in severe cases.

2. Measures

First of all, we should clean up the weeds after winter, and then water and fertilize them.

Secondly, the branches should be arranged and the leaves should be cleared so that all its leaves can be exposed to light and can be blown by the wind.

Finally, we need to give it carbendazim, and it is also feasible to use 0.3 and 0.5 lime-sulfur mixtures. Usually spray once every ten days or three times in a row.

2. White rust

1. Reason

This disease is mainly caused by germs spending the winter in the soil or above the plant, and this kind of harm will occur in the next season. It is equivalent to artificial field operations to spread, and if the flowerpot is too dense can also spread, high-pressure water spray will also spread with the water. Tiny spots appear on the leaves at the beginning of the disease, then become larger, and then become light yellowish brown. If it is more serious, the plant will also die.

2. Measures

First of all, fertilizer should be applied, phosphorus and potassium fertilizer should be increased, and this plant will have a higher resistance to bacteria.

Then we should often drain the water so that there is no water in the basin. Get rid of the weeds and get rid of the diseased leaves.

In Rain Water's sufficient season, use 65% of Dyson zinc, or 0. 3 to 0. 5 stone sulfur mixture, at intervals of 10 to 15 days, which can curb the spread of the disease. In addition, carbendazim or topiramate can be used.