Grain filling period and yield components in bread wheat

Vegetative and grain filling periods are yield related physiological attributes of wheat. An attempt has been made to know effects of maturity date on these characters. With few exceptions, the variations among the maturity groups were significant. Variability reduced for most characters due to classification of genotypes based on maturity time, as evidenced from low GCV, PCV, h2 and GA in all maturity groups than overall basis. Relationship between earliness and fecundity characters became stronger in early genotypes than its later counterparts. The changes in magnitude of correlations may be due to maturity effects and probably arised due to development of more and more early cultivars with efficient partitioning of total biomass production.