Effects of Environmental Changes on the Physiological Indexes and Yield in Maize

Five-year field experiments were conducted using late-maturing and sparse-planting variety Danyu 39, medium-late-maturing and close-planting variety Zhengdan 958 as experimental materials to evaluate the relationship between physiological indexes and environmental changes. The results were shown that physiological indexes responded differently to environmental changes from year to year. Sunshine hours and light intensity were the main factors affecting physiological indexes, and then temperature. Photosynthetic rate affected the most, followed by chlorophyll content and light transmittance. Environmental changes led to the accumulation changes of photosynthetic products between years, thereby affecting the yield formation. The contributions of physiological index of the yield were different. Contribution rate of chlorophyll content to the yield in Danyu 39 was great, secondly for photosynthetic rate. Photosynthetic rate was dominant factor in affecting the yield of Zhengdan 958.