Water stress alters physical and chemical quality in grains of common bean, triticale and wheat

Wheat, triticale and common bean are planted in both irrigated and rainfed conditions and may suffer the effects of water stress in both situations. The objective of this work was to evaluate the effect of water stress on the physical and chemical qualities of wheat (Triticum aestivum), triticale (Triticosecale wittmack) and common bean (Phaseolus vulgaris L.) grains. The experiment was conducted at the Embrapa Cerrados experimental station, in Planaltina, DF, Brazil. The experimental design was in randomized blocks with four replications. The treatments were composed of four water regimes (187 mm, 304 mm, 410 mm, 535 mm) applied to common bean (BRS Realce), two wheat genotypes (CPAC 0544 and BRS 404) and triticale (BRS Ulisses). The physical quality of grains was evaluated by the weight of a thousand grains (WTG) and color of the grains (represented by the luminosity (L*), chroma (C*) and hue angle (h*); the chemical quality was determined by protein, carbohydrate, lipid, ash, macro and microminerals contents. Water stress reduced grain yield of all species, however it did not reduce the weight of one thousand grains of the wheat genotype BRS 404, showing the potential of this cultivar, though it did lead to reduced WTG in common bean, triticale and the wheat genotype CPAC 0544. There was also a reduction of luminosity (L*) in the grains for both studied wheat genotypes, and chroma (C*) and hue angle (h*) for triticale. Water deficit also affected protein, carbohydrate, lipid and ash contents, with an increase in the protein content and a reduction in the carbohydrate and ash contents in common bean. In general, water stress reduced macro and micromineral contents in the grains, caused an undesirable change in the physical quality of the grains, and affected the chemical quality of the grains.