Effects of Shade and Light Recovery on Soybean Cultivars(Lines) and Its Re-lationship with Yield in Relay Strip Intercropping System

Abstract

A field experiment was conducted to compare agronomic traits during shade and light recovery periods between high yield and low yield soybean cultivars undershade net or in maize-soybean relay strip intercropping in 2013 and 2014. Twenty typical soybean varieties with different yield levels in relay cropping in south of China were used. The results showed that during shade period stem dry weight and leaf dry weight were significantly lower than those of control, the dry weight ratio of stem and leaf was 58.4% and 41.6% respectively under shade. Compared with the high yield soybeans, low yield cultivars had significantly higher decline rate of aboveground dry weight, stem length, stem length/ stem diameter, stem length/ aboveground dry weight, stem length/ leaf area and the yield was positively correlated with aboveground dry weight, and negatively correlated with stem weight ratio during shade period. During light recovery period, aboveground dry weight and leaf area increased rapidly, soybean showed more leaf weight ratio, stem dry weight and leaf dry weight were 47.7% and 52.3% respectively at 30 days after the re- covery of light. High yield soybeans had significantly higher aboveground dry weight, leaf area, stem diameter, leaf weight ratio and significantly smaller stem length/ stem diameter, stem length/aboveground dry weight, stem length/leaf area. In light reco- very duration, yield was positively correlated with aboveground dry weight, stem diameter, leaf area, and leaf weight ratio, and