Agronomic Characters And Their Correlations With Yield In Summer Soybean Varieties Of Different Growth Habits

355 soybean varieties with different growth habits growing at Huanghuai summer sowing region were employed to investigate the agronomic traits and yield and the correlation of them.The results indicated that the average of the vegetative period,plant height,effective branches,and pods per plant,lodging,and plant type traits reduced progressively following the change from indeterminate,sub-determinate to determinate soybeans.The opposite trend was found in reproductive period,seed weight per plant,100-seed weight,and plot yield.The highest plot yield in sub-determinate soybean varieties was 1346.7g,which was higher than that of determinate growth habit varieties of 1242.3g.While,the maximum yield of sub-indeterminate growth habit varieties.Highly significant positive correlation was found between yield and plant height,seed weight per plant in indeterminate soybean accessions with the partial correlation coefficient of 0.602**,0.566**,respectively,while the significant correlation was negative between yield and effective branch,lodging of-0.384* and-0.451* based on partial correlation analysis.In contrast,in sub-determinate soybeans accessions,positive correlation between yield and seed weight per plant,effective branches were significant and highly significant.The partial correlation coefficient was as follows:0.156* and 0.536**.The significant correlation between yield and effective branch was high and negative as-0.323**.The partial correlation coefficient of 0.433**,0.262**,-0.160*,-0.202** happened between yield and seed weight per plant,plant height,plant type,pods per plant in determinate soybean varieties.Combined with the growth characteristics of soybean varieties of growth habits,the study suggested that indeterminate soybean varieties be more suitable for growing in arid areas and the sub-determinate have higher yield potential and high requirement for nutrients supply during reproductive period.Meanwhile,short vegetative stage and limited absorption of light energy led to short plant height in determinate soybean varieties.The formation of high-yielding trait mainly depended on the balance between the various traits.So,during vegetative growth of the determinate,plenty of fertilizer supply is indispensable and excessive growth should be avoided.