Physiological studies of barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) grown under limiting water conditions

Abstract

Four barley (Hordeum vulgare L) and two wheat (Triticum aestivum L) cultivars were grown with a preplant irrigation plus rainfall at the University of Arizona Marana Agricultural Center to study the relationship of growth and physiological characteristics to yield under limiting moisture condition. Grain yield of barley cultivars were ranked in the order Bold = 4-21-13 > 309-1, but increased yields were not related to early maturation dates or to other reproductive or vegetative characteristic which was examined. Grain removal by birds prevented the determination of wheat yields, but Zaragoza, which is known to perform well with limited water, had a deeper root system and higher water potentials than LIP-40. Laboratory measurements of severe osmotic stress (-0.8, -0.9 and -1.15 MPa) effects on leaf growth and physiology of barley leaves showed stress stopped leaf expansion immediately and led to rapid leaf shrinkage before growth resumed. Growth occurred in the basal 0.5 cm, and growth resumed when water potential of the growing region became -0.19 MPa lower than that of the external solution.