Effect of source size and its position on grain yield in finger millet (Eleusine coracana L.)

Improved finger millet yield was through an increased harvest index, which compensated for the biomass production. In finger millet, the photosynthetic rate is relatively high, and the leaf area (source size) is the limiting factor for biomass production and grain yield. Therefore, the effects of source size (25, 50, 75, and 100% leaf removal) on yield-contributing traits, grain yield, and seedling vigor were studied to determine the optimum source size and position of leaves on the plant for higher grain yield. The reduced source size brought the crop to early maturity, and decreased the yield-contributing traits. However, removal of 25% of leaves from the base did not decrease the yield-contributing traits significantly; hence, retaining the upper 75% of leaves after flowering could be sufficient for higher grain yield in finger millet. Correlation data showed that the source size (LAI) had a strong positive relationship with stem weight (r = 0.806**), total dry matter (r = 0.847**), test weight (r = 0.645**), finger number (r = 0.554**), mean ear weight (r = 0.417*), and grain yield (r = 0.642**). Path analysis revealed a significant positive direct effect of mean ear weight (0.790**) and productive tillers (0.510**) on the grain yield. The observed and estimated grain yields were increased with increasing LAI up to 4.0, and not beyond. The decreased seed size significantly decreased the seedling length, root/shoot ratio, and seedling dry weight. It is concluded that 75% of upper leaves with an LAI of 4.0 at flowering could be ideal for higher grain yield in finger millet.