Relationships between the Lengths of the Vegetative and Grain Filling Periods and Agronomic Characters in Three Durum Wheat Crosses1

Abstract

Random sets of lines from three durum wheat (Triticum turgidum L.) crosses were developed by single seed descent to study the relationship between yield and the lengths of the vegetative and grain filling periods. The parents of the three crosses, ‘Pelissier’/‘Hercules’, ‘Stewart 63’/‘Anhinga’, and ‘Wakooma’/‘Anhinga’, were selected to represent different combinations of the lengths of the vegetative and filling periods. The random lines were tested in rainfed field experiments in 1982 and irrigated experiments in 1983, and eight characteristics were measured—lengths of the vegetative and filling periods, days to maturity, height, straw strength, yield, weight per 1000 kernels, and protein content. The lengths of the vegetative and filling periods were negatively correlated in both years. Correlations between yield and the lengths of the two growth periods were inconsistent and generally fairly small. The data provided no indication that there was an optimum combination of the lengths of the vegetative and filling periods that gave maximum yield. Yield and protein content showed a significant negative correlation in only two of six tests.