The latest control methods of tomato Botrytis cinerea

Gray mold is a serious and common disease on tomatoes, but also an important disease of greenhouse tomato cultivation, all vegetable areas occur, in addition to endangering tomatoes, but also can harm eggplant, pepper, cucumber, gourd and other more than 20 kinds of crops, low temperature, continuous rainy weather more serious harm, let's take a look at the tomato gray mold control method!

hazard symptom

Tomato gray mold can harm stems, leaves, flowers and fruits, but it mainly harms fruits, usually green fruits. When the stem is infected, it begins to be water-soaked, then expands into oblong or irregular shape, light brown, gray mold layer is born on the surface of the disease spot when humidity is high, and the stem and leaf above the diseased part die seriously, resulting in blight. The disease of leaves starts from the tip of leaves, expands inward along the branches in a "V" shape, initially presents a water-soaked shape, and after expansion, it is yellow-brown, with irregular edges and alternating light and dark ring patterns. The boundary between diseased and healthy tissues is obvious, and a small amount of gray mold layer is produced on the surface. Fruit infected, residual stigma or petals were infected first, and then to the fruit or fruit stalk expansion, resulting in a gray peel, and a thick gray mold layer, was water-rotten.

occurrence regularity

Botrytis cinerea is a weak parasitic fungus, which can survive on organic matter. Under the condition of low illumination, when the air humidity is above 90%, the disease can occur at 4~31℃, but the suitable temperature for development is 20~23℃, the highest temperature is 32℃, the lowest temperature is 4℃. The humidity requirement is strict. The disease begins when the air relative humidity reaches 90%. The high humidity maintains for a long time and the disease is serious. Less illumination, suitable temperature (about 20℃) and high relative humidity (more than 90%) are beneficial to the disease. The host growth weak, easy to induce this disease. The infection period of the pathogen to tomato is flowering and fruiting period, and the pathogen spores have a long latent time in the pathogen. If the tomato has rotted, that is to say, the infected spores of gray mold have invaded the fruit from the style or petal, which is bound to cause rot. At this time, it is too late to reapply the medicine.

control methods

1, agricultural control: the most important measures to control tomato gray mold is to try to do a good job in the greenhouse ventilation, light transmission, humidity, but at the same time to keep the temperature not too low. Secondly, we should strengthen the management of fertilizer and water to make the plants grow vigorously and prevent premature aging and wounds caused by various factors. Discovered diseased plants, diseased fruit should be removed and destroyed in time, after harvest thoroughly clean garden, turn over the soil, can reduce the source of bacteria.

2. Chemical control: 50% Sukeling wettable powder 1500~2000 times solution, or 40% polysulfide suspension 400 times solution, or 50% iprohydantoin wettable powder 1000~1500 times solution, or 70% thiophane methyl 800~1000 times solution, spray once every 7~10 days, spray 3~4 times continuously. It is important to note that bacteria are prone to resistance, so the same agent cannot be used during a growth period, and the above agents need to be used alternately.