Abstract:

To explore the relationship between canopy temperature of walnut and atmospheric temperature in southern Hebei province, this study took Kangyuan Walnut base in Shahe City, southern Hebei Province as the research object, monitored the characteristics of canopy temperature changes in key growth stages of walnut at different altitudes, and used statistical analysis methods to conduct regression analysis on the data of canopy temperature and atmospheric temperature. The results indicated that the canopy temperature at different altitudes was highly positively correlated with the atmospheric temperature, with correlation coefficients ranging from 0.91 to 0.98 and coefficients of determination all exceeding 0.75, showing high positive correlation. When the atmospheric temperature is 35-39℃, there is little difference between the atmospheric temperature and the maximum canopy temperature of walnut. When the atmospheric temperature is higher than 40℃, the maximum canopy temperature is 2.8℃ higher than the atmospheric temperature. The minimum temperature of the canopy is most sensitive to the influence of altitude, and the low temperature period is from 4:00 to 6:30. The time and date of the minimum temperature of the walnut canopy are lagging behind that of the atmospheric temperature, and the minimum temperature is about 2.7℃ lower than the atmospheric temperature. The research will provide scientific support for the early warning of low temperature freezing damage and high temperature sunburn risk in agricultural meteorological service.

Key words: walnut, canopy temperature, atmospheric temperature, altitude