Relative sensitivity of spring wheat grain yield and quality parameters to moisture deficit

Moisture stress influences both yield and end-use quality of wheat (Triticum aestivum L.). Previous studies assessed stability of yield and yield components to moisture stress. This study evaluated the stability of spring wheat quality parameters relative to the stability of grain yield and its components under moisture stress. Sixteen spring wheat cultivars were produced under two moisture-deficit regimes in 1995 and 1996 to determine the effects of moisture-deficit severity on grain yield and its components, test weight, flour protein, flour extraction, dough-mixing characteristics, and alkaline noodle color. Moisture deficit differentially and significantly influenced cultivar test weight and yield. The overall moisture-deficit-induced reduction in yield was due primarily to reduction in kernel,weight; effects of moisture deficit on yield of specific cultivars were due largely to effects on kernels per spike. Drought-sensitivity indices (DSIs) for yield were correlated to cultivar yield potential. Yield reduction by moderate moisture deficit was not predictive of yield reduction by severe moisture deficit. Effects of moisture-deficit severity on flour extraction and mixograph peak time varied with cultivar. Moisture deficit reduced initial noodle brightness and enhanced noodle yellowness. However, the color of noodles produced by the cultivars included in this study responded similarly to moisture deficit, 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.