Abstract:

Eight soybean cultivars with similar growth duration were chosen for this study, including five semi-determinate cultivars and three determinate ones. Trifoliolate leaf area was measured after the top leaf was fully expanded, seed weight each node was measured after harvest, and the ratio of seed weight/leaf area each node was calculated. Results showed that apical dominance of podding existed in both semi-determinate and determinate cultivars, and assimilates in the top grain were also from leaves of the penultimate node. Through the correlation analysis between leaf area and its corresponding seed weight, it was found that there were highly significant correlations among semi-determinate cultivars, while no significant correlations among determinate cultivars. A significant difference of grain productivity per leaf area at the upper nodes was observed among different soybean cultivars. Results revealed that high-yield cultivars had higher ratio of seed weight/leaf area at each node; therefore, leaf productivity could be evaluated by ratio of seed weight/leaf area at each node of upper nodes in soybean.

Key words: Soybean, Ratio of seed /leaf, Leaf productivity