Abstract:

Under the background of global climate change, extreme low temperature events occur frequently, which seriously restricts the sustainable development of agriculture. In order to systematically sort out the harm and prevention and control technology of low temperature disasters, based on a large number of literatures, this paper expounds the concept and classification characteristics of cold damage, freezing damage and frost, summarizes the impact mechanism of different types of low temperature disasters on crops, and discusses the targeted prevention and control measures. The results showed that there were significant differences in disaster temperature, occurrence season, affected area and hazard object among cold damage (>0 ℃), freezing damage(<0 ℃) and frost (≤ 0 ℃); cold damage mainly led to physiological dysfunction of crops (such as photosynthetic inhibition and metabolic disorder), freezing damage caused cell freezing and tissue necrosis, and frost caused cell membrane rupture and water imbalance, all of which significantly reduced the yield and quality of crops; breeding cold resistant varieties, optimizing field management (such as mulching, irrigation, smoking), and strengthening the monitoring and early warning system can effectively reduce the loss of low temperature disasters. In the future, it is necessary to strengthen the research on the evolution trend of low temperature disasters and the mechanism of crop cold resistance, and improve the comprehensive prevention and control system in combination with molecular breeding, intelligent agriculture and other technologies, so as to provide support for food security.

Key words: low temperature disaster, cold damage, freezing damage, frost, crops, influence mechanism, prevention and control measures