科学防病控害，最大限度减轻灾害影响

Core Viewpoint - The article emphasizes the need for technical guidance to mitigate the impact of severe cold wave and snowfall on facility vegetable production, ensuring stable supply of agricultural products during adverse weather conditions [1]. Group 1: Weather Impact and Response - A cold wave with significant snowfall and temperature drops is forecasted from January 17 to 20, which poses risks to facility vegetable production [1]. - The provincial agricultural authorities have issued technical guidance to minimize the adverse effects of this weather event [1]. Group 2: Snow Removal and Facility Safety - Timely snow removal is crucial; snow should be cleared after snowfall to prevent excessive accumulation that could collapse greenhouses [2]. - Continuous monitoring of weather conditions and snow dynamics is recommended, with specific strategies for different snowfall scenarios [2]. - Strengthening the structural integrity of greenhouses is advised, including reinforcing frames and checking for any damage to the covering materials [2]. Group 3: Temperature Management - To prevent frost damage, it is suggested to use double-layer coverings and thermal barriers around greenhouses to retain heat [2]. - Emergency heating measures should be implemented when nighttime temperatures drop below 8°C, using safe heating devices [2]. - Recommended temperature ranges for different vegetable types during nighttime are specified: 8°C to 10°C for fruit and vegetable crops, and 10°C to 13°C for leafy vegetables [2]. Group 4: Field Management and Disease Control - Watering should be strictly controlled during cold and snowy conditions to avoid lowering soil temperature and increasing humidity, which can exacerbate cold damage [3]. - Gradual warming techniques should be employed if frost damage occurs, avoiding sudden temperature changes that could harm the plants [3]. - Maintaining low humidity levels in greenhouses is essential to prevent high-moisture diseases, with recommendations for short ventilation periods during warmer midday hours [3].