WATER DEFICIENCY RESISTANCE STUDY ON SOYA AND BEAN CULTIVARS

Abstract

In a three-year model experiment the water deficiency resistance and the quality of yield were investigated in the case of soybean and bean cultivars of determined growth. The plants were grown under irrigated and non-irrigated conditions, modelling the conditions of drought. The soybean cultivars used a considerably higher amount of water before reaching the green pod maturity stage than the bean cultivars. Their water use under water stress decreased considerably (46%), in contrast with beans, where this decrease was only 18–21%. This correlates with the vegetation period of the varieties, their water use in certain vegetation periods and the development of their roots. The roots of beans determine the size of the yield and that of water circulation but only affects the formation of pods in a few varieties. The roots of soybean cultivars affect the size of yield and the quality of seeds as well. This is especially important in organic matter circulation under water-deficient conditions. If the roots are small, the dry matter and oil contents increase more intensively in the seed, but this has no effect on the protein content of the seeds. The small root mass and small specific leaf area (SLA) of the early soybean cultivar McCall and the Hungold variety of beans decreased yield losses under water deficiency conditions, in contrast with the mid-late maturing soybean variety Evans, where this was not experienced.