We investigated the effects of chemical ripeners Diguat and Roundup on photosynthetic rate, gas exchange parameters and chlorophyll content in pods, 1000-grain weight and yield and oil content through gas exchange measuring technology during the latest stage of pod growth. The ripener Diquat, with a good effect on accelerating pods ripening, damaged pod peel chlorophyll seriously, decreased photosynthetic rate, and light-energy utilization efficiency rapidly, so that the 1000-grain weight, yield and quality decreased largely, which sensitively depends on the Diquat content. In comparison, the ...