Physiological adaptation for high sorghum productivity for grain (Sorghum bicolor L Moench)

An experiment was performed to estimate the effects of respiration on adaptation and productivity in two sorghum genotypes (Sorghum bicolor L. Moench). Leaf area efficiencies on dry matter and grain yield were estimated along with dark respiration in two hybrids with different adaptation to tropical environment. Night respiration greatly influenced leaf area efficiencies in both. The tropical hybrid showed lower respiration rates than the temperate hybrid. This difference is ascribed to differences in their respective adaptation backgrounds. Use of genotypes with tropical adaptation is recommended in breeding programs targeted to hybrid production for the tropics.