1, disease symptoms: Tomato late blight is an oomycete fungal disease that is common during tomato planting and can cause serious losses. Tomatoes have a very rapid incidence of late blight. The lesions are black and irregular. The white mold layer can be seen on the lesions when wet. The upper part of the stems is wilting and dead. 2, control methods: Pay attention to the rotation and disinfection of the land and use rain-fence cultivation. Chemical control can be used 25% azoxystrobin suspension 1000 times, 72% metalaxyl. Manganese zinc 600 times, dimethomorph. Manganese zinc 69% WP800 times, 72.2% Protease Weidesen. Manganese zinc Aqueous agent 800 times liquid, capsaicin, widienoic morpholine, and mancozeb, can be sprayed with 1.5% polyoxin 300 times in the morning or evening, spray once every 4 days. Difenoconazole can be added to prevent other diseases. The valve is a series of gas emergency shut off solenoid valves, specially designed as gas pipe breaker for emergency use. It can be connected with gas leaking detection sensor, fire alarm circuit or other intelligent sensor modules so that on site or remote shut down on gas supply (manually or automatically) is possible, hence ensuring the safety on gas usage. The valve features an auto-close when strong vibration is detected. After close, manual operation is required to turn on the valve. This feature meets safety regulations in the event of an accident. Gas Cut Off Valve,Air Solenoid Valve,3 Way Solenoid Valve,Sprinkler Valve Solenoid Rictron Industrial Co., Ltd , https://www.szrictron.com