Duration of the vegetative and reproductive period in relation to yield performance of spring wheat

Abstract

The durations of the vegetative growth period (VGP) and the grain filling period (GFP) of cereal crops influence their yield. Thus, the optimization of VGP and GFP results in higher grain yield. This study was conducted to i) examine variation in growth periods of spring wheat (Triticum aestivum L.) genotypes ; ii) determine the proportions of entire growth period occupied by VGP and GFP ; and iii) examine associations between growth period durations and yield. Twelve wheat genotypes of diverse backgrounds were evaluated in replicated trials in Nepal over three years (1988 to 1990). The characters evaluated were VGP, GFP, crop duration period (CDP), the proportions of CDP occupied by VGP (PVGP) and GFP (PGFP), grain yield (GRY), and biomass yield (BMY). Year and genotype × year interactions were significant for all traits. Mean values for VGP, GFP, CDP, PGFP, GRY, and BMY were lower in 1988 and 1990 than in 1989. Significant positive correlations of GFP and PGFP with GRY and BMY suggested that selection for long GFP will lead to improved yields. The negative correlation between VGP and GFP suggested that selection for long GFP would also result in early heading. Results suggest that a combination of short VGP and long GFP may produce higher grain yield in wheat.