How to prevent and control tomato powdery mildew? A detailed explanation of the latest control methods
The tomato is the tomato we commonly see in our daily lives. It is very popular with many people and is grown across a very wide area in our country. When growing tomatoes, many pests and diseases often harm the growth of the tomatoes, and the most common of these is powdery mildew. So what symptoms does tomato powdery mildew have? And how should it be prevented and controlled? Below, the editor will give everyone a brief introduction. Let's take a look together!
1. Disease symptoms
Tomato powdery mildew mainly harms tomato leaves. In the early stage of the disease, many small mold spots appear on the tomato leaves, and the mold spots are white in color. They then gradually expand into white patches, and the spots merge with each other to form lesions. When the disease is severe, the entire leaf becomes covered in a powdery white coating, and finally the leaves wither and fall off. In addition to the leaves, the petioles, stems and fruit of the tomato can also be infected, and white mold layers also appear on them. The powdery white substance is the conidia of powdery mildew.
2. Occurrence patterns
The occurrence patterns of powdery mildew differ depending on the growing region. For example, in the north, the powdery mildew pathogen overwinters on winter-crop tomatoes, and can also overwinter in soil, diseased plant debris and other materials. It then releases ascospores, which spread and infect through air, rainwater and so on, and then the diseased plants release new conidia, and the cycle repeats. If grown in the south, the conidia reproduce very quickly, spreading continuously and expanding the affected area. The optimum temperature for conidia to cause damage is around 22 degrees. In open-field cultivation it generally occurs from June to October, with less in August, while in greenhouse cultivation it is concentrated in April to May.
3. Prevention and control methods
First, we need to choose an excellent variety to ensure strong disease resistance, and then disinfect the seeds before planting to reduce the base number of pathogens. After planting, pay attention to controlling temperature and humidity well, and avoid creating a high-temperature, high-humidity environment. After harvest, pay attention to promptly removing diseased plant debris, do a good job of cleaning the garden, destroy the overwintering sites of the pathogen, and reduce the occurrence of the disease the following year. Then strengthen prevention by spraying chemicals such as triadimefon and Fuxing emulsifiable concentrate for preventive control.
In the early stage of powdery mildew, if it is grown in a greenhouse, use dust or smoke methods to disinfect the whole garden. Then pay attention to promptly removing diseased leaves, and use chemicals such as triadimefon and Wuyi mycin aqueous solution for spray control. Spray about once a week for one month to inhibit the reproduction and spread of powdery mildew conidia and reduce the affected area.
The above is a brief introduction to the prevention and control methods for tomato powdery mildew. Tomato powdery mildew is only one of the common pests and diseases of tomatoes, and there are many other pests and diseases that require our attention, so we hope everyone will pay more attention. That is all for today's introduction. This article is for reference only. Thank you all for reading and supporting.