Relative sensitivity of spring wheat grain yield and quality parameters tomoisture deficit

Moisture stress influences both yield and end-use quality of wheat (Triticu m aestivum L.). Previous studies assessed stability of yield and yield comp onents to moisture stress. This study evaluated the stability of spring whe at quality parameters relative to the stability of grain yield and its comp onents under moisture stress. Sixteen spring wheat cultivars were produced under two moisture-deficit regimes in 1995 and 1996 to determine the effect s of moisture-deficit severity on grain yield and its components, test weig ht, flour protein, flour extraction, dough-mixing characteristics, and alka line noodle color. Moisture deficit differentially and significantly influe nced cultivar test weight and yield. The overall moisture-deficit-induced r eduction in yield was due primarily to reduction in kernel,weight; effects of moisture deficit on yield of specific cultivars were due largely to effe cts on kernels per spike. Drought-sensitivity indices (DSIs) for yield were correlated to cultivar yield potential. Yield reduction by moderate moistu re deficit was not predictive of yield reduction by severe moisture deficit . Effects of moisture-deficit severity on flour extraction and mixograph pe ak time varied with cultivar. Moisture deficit reduced initial noodle brigh tness and enhanced noodle yellowness. However, the color of noodles produce d by the cultivars included in this study responded similarly to moisture d eficit, suggesting that evaluation of noodle color may not require testing across moisture-deficit environments. Test weight and flour extraction DSIs were correlated,vith DSIs for grain yield. Therefore, identifying drought- tolerant genotypes based on yield stability under moisture stress also will identify genotypes having stable test weight and flour extraction.