Control measures for tomato gray leaf spot and cucumber target spot
In crop planting, spot disease is generally a cage term for vegetable farmers for some vegetable diseases. Spot disease is actually one of the necrotic conditions in vegetable diseases, that is, the death of cells and tissues in leaves, fruits, stems and other parts. The shape and color of the spots are various, and the shapes are polygonal, round, streak, ring spot, wheel spot, etc., and the colors are yellow, gray, black, white, brown, and the like. Some of the lesions tend to dry out and form perforations. In addition, freezing damage, phytotoxicity, and fertilizer damage can also cause spots. In vegetable production, there are two main types of spot disease faced by vegetable growers: 1, tomato gray leaf spot disease. At the beginning of the tomato gray leaf spot disease, the leaf surface is covered with dark round or irregular small spots, and the veins along the veins are enlarged to the periphery, showing an irregular shape, and the middle part gradually fades to grayish to taupe. The lesions are slightly concave, small, 3-8 mm in diameter, extremely thin, and easy to rupture at the later stage, causing the leaves to break or even fall off. 2, cucumber target spot disease. The cucumber target spot disease is initially a yellow water-immersed spot with a diameter of about 1 mm. In the middle stage of the disease, the lesions are round or irregular, easy to perforate, and the lesions on the front of the leaves are rough and uneven. The lesions are brown in color and the center is grayish white and translucent. The lesions can reach 10~15 mm in diameter, and there is a clear eye-shaped target in the center of the lesion. When the humidity is high, there may be sparse gray-black mildew on the lesion, which is ring-shaped. Once these two diseases have reached the middle and late stages, they have a great impact on the yield and quality of vegetables, which has almost become the cause of each vegetable grower. So how do you prevent these two diseases? 1. First of all, the vegetable farmers themselves must establish the basic concept of prevention and treatment. In the prevention of gray leaf spot and target spot disease, controlling humidity is the key, the greenhouse humidity is controlled below 70%, and chlorothalonil or nail protection is sprayed weekly for prevention. 2. When the greenhouse vegetable plants appear to be closed, on the basis of good chemical prevention, timely leaf thinning, improve the inter-line transparency, and also make a good foundation for spraying. 3. Chemical control. At the time of treatment, a contact and a systemic agent should be used. For example, the protective plant is a contact-killing agent, which can inhibit and kill pathogenic spores through comprehensive and careful spraying, and has the effect of prevention and treatment. Preventing problems before they have always been an old saying, this is also very suitable for crop production. The vegetable farmers have to kill the germs in the soil, try not to let the disease happen, not only save the cost of medicine but also ensure the safety of crops. Oxygen Bag,Medical Oxygen Bag,O2 Bag,Oxygen Purse Hebei Dingli Medical Equipment Co., Ltd. , https://www.dinglimed.com
