Tomato Powdery Mildew: Symptoms, Identification and Key Points of Control Techniques Explained

The tomato is a common vegetable that can be eaten raw or cooked, and can also be processed into foods such as tomato paste and tomato juice. Tomatoes are grown all over our country, prefer to grow in warm places, and are not very demanding about soil. However, if management is improper, tomato powdery mildew easily appears. So what are the symptoms of this disease? What are the key points of control techniques?

1. Symptoms of tomato powdery mildew

Once a tomato is attacked by powdery mildew, if it is not treated in time, reduced yield and poor fruit quality will occur. This is because tomato powdery mildew mainly damages the leaves, petioles, stems and fruits of the tomato. In the early stage of the disease, a white powdery substance appears; this is actually the hyphae, conidia and so on of the powdery mildew pathogen. At first there will not be much, only sparse white spots, and as the disease worsens it will gradually thicken. In addition, yellow-green spots appear at the edges. If it is not treated at this point, it will cause the entire tomato plant to wither and die, which means “not a single grain harvested”.

Tomato powdery mildew appears very easily in relatively dry environments, and the main pathogen is in the north. Tomato powdery mildew spreads and expands with airflow, infects newly growing leaves, and then continues to infect through airflow again. Therefore, prevention in advance is very necessary. Let us look together at the specific control methods below.

2. Key points of tomato powdery mildew control techniques

1. Choose tomato varieties with strong disease resistance, and pay special attention to humidity management in the tomato growing greenhouse, because dryness is one of the causes of this disease. After the tomato harvest, promptly clean up the diseased tomato plant debris to reduce the source of disease pathogens during overwintering; this is also one of the methods to effectively curb the occurrence of this disease.

2. In the early stage of tomato powdery mildew, when it is still not very serious, smoke method or dust method can be used for disinfection treatment. In the evening, spray some dust powder; the single dose must strictly follow the instructions for use, not more than 2 jin per mu. If the smoke method is chosen for disinfection, it must be lit with a low flame and fumigated for one night, otherwise it is difficult to achieve the effect.

3. During the tomato growing process, strictly control the planting density, fertilization method, air humidity, watering method and so on, keep the environment inside the tomato growing greenhouse dry, and only maintain appropriate humidity.

4. When the disease is relatively serious, professional chemicals must be used for treatment. Be sure to ask at the pesticide market about the method of use, and also strictly follow the instructions yourself. When spraying, try to spray on the back of the leaves, with an interval of one week each time, and note to alternate the chemicals to avoid developing resistance.

Through the above introduction, I believe everyone has gained some understanding of tomato powdery mildew, and I hope it is helpful to you.