Analyzing Thermal Infrared Image Characteristics of Maize Seedling Stage

The temperature of crop leaf is closely related to leaf respiration, transpiration and its drought resistance. The rapid measurement of crop temperature is of great significance for breeding and agricultural cultivation management. The traditional infrared thermometer can only obtain the single point temperature. In this study, a high sensitive thermal infrared imager was used for recording the leaf temperature distribution of maize seedling stage. The temperature distribution of 5 different drought resistance varieties of maize in both normal water and drought stress treatment were analyzed. It turned out that there were obvious differences in temperature for different leaf position. The average temperature in the middle part of the leaf is 0.94℃ higher than the leaf apex and 0.81℃ higher than the leaf base. The results also showed that the leaf temperature is higher than that of the stem. And the average temperature of the whole blade is 24.07℃, which is higher than the background soil temperature (19.53℃). For the same maize variety, the leaf temperature of drought stress treatment is higher than that of normal water treatment. It was also found that the temperature of maize with good drought resistance is higher than that of the bad one, furthermore, the better the higher. The results above showed that the characteristics of temperature distribution in crops could be effectively obtained by using thermal infrared images, which also provided potential for the rapid identification of crop drought resistance.