According to previous years' experience, under the conditions of low temperature and high humidity in April and May, the diseases that most easily occur in greenhouses are gray mold, leaf mold, and phytophthora root rot. Attention should be paid to prevention and control. Tomato gray mold from the seedling stage, adult stage, flowering period, fruit enlargement period can be the disease. Leaves, stems, flowers, fruits can be infected. Large planting density, poor ventilation and disease conditions. When the greenhouse humidity is between 15°C~25°C and the relative humidity exceeds 85%, Botrytis cinerea can continue to occur. Measures for Prevention and Control (1) In the event of cooling weather, watering should be stopped. If there is a severe drought, sunny water should be selected to prevent the increase of humidity. (2) reduce the area of ​​water, fertilizer can be added to the fertilizer when adding 2 kg of soil-free deep ploughing soil conditioner. Without deep ploughing the soil conditioner can break the soil compaction, increase the permeability of the soil, is conducive to the penetration of the surface of the water, so that the ground to reduce the water time, thereby reducing the humidity and diseases in the shed. (3) Chemical control. Select Bacteroide (Moramide Manganese Salt) 1000~2000 times liquid plus 3000 times liquid Shuofeng 481 through the foliar spray, 7 days once, and even spray 2~3 times; also can use 1500 times procymidone to add bacteria Wei ( Micamide manganese salt) 2000 times and then 3000 times liquid Shuofeng 481 mixed, the foliar spray, 7 to 10 days once, and even spray 2 or 3 times. Tomato leaf mold Tomato leaf mold is mainly harmful to the leaves, but it can also harm stems, flowers and fruits in severe cases. On the occurrence of the leaves, irregular or oval yellowish chlorotic spots appeared on the front of the leaves and the edges were not obvious. On the back of the leaves, grayish white to dark brown velvety mildew layer appeared, and later turned to purple gray or dark gray to black or yellow brown spots. When the humidity is high, the mildew layer can grow on the surface of the leaves. As the disease spreads, the leaves gradually curled from the lower to the upper, and the lower leaves of the diseased plants began to develop. Afterwards, they gradually spread upwards, leaving the entire plant yellow and brown. Prevention measures (1) Minimize foliar condensation, strengthen ventilation, fight in time, remove old leaves, and increase light conditions. (2) To avoid partial nitrogen fertilizer application and increase phosphorus and potassium fertilizers, spray high-energy red potassium and Shuofeng 481 on foliar, and increase plant disease resistance. (3) Chemical control: Use Bangjiawei 600~800 times liquid and 3000 times liquid Shuofeng 481, spraying on the foliar stage at the onset of the disease, and spray it 2~3 times in 7 days at one time; also use 40% fluorosiliconazole EC 4000 The liquid plus Jia Bang Jia Wei 600 ~ 800 times the liquid, 7 to 10 days once, and even spray 1 or 2 times. Phytophthora capsici root rot disease at the beginning of the primary root, fibrous roots and secondary roots produce water-like light brown rot, after the emergence of brown lesions at the base of the stem, the disease of the sick disease around the base of the stem a week, causing wilting plants above the ground. In the longitudinal section of the root and base of the stem, it can be seen that the vascular bundle of the diseased plant turns brown from a few centimeters to a few tens of centimeters from the ground. The rootstock is rotted and no new roots are produced. The upper part of the tomato nourishes the wilting at noon, recovers sooner or later, and dies after a few days. Prevention measures (1) Watering is prohibited in cool and rainy days. (2) Appropriate use of chemical fertilizers to prevent excessive fertilizer damage to tomato roots. (3) For the onset of the disease, when the central diseased plant has just been discovered, 72% of frosturea, Mn-Zn wettable powder 800-1500 times can be used to irrigate the root; 600 times of Dunin and thiophanate-methyl 1000 can also be used. The liquid mixture was used for root filling, and the foliar spraying of Shuofeng 481 and high-energy red potassium promoted the rooting of the crops, promptly added potassium, reduced the leaf surface evaporation, and improved the disease resistance of the tomato.
KN90 Mask
Ningbo DOKEE Medical Technology Co., Ltd. , https://www.dokeemedical.com