PHOTOSYNTHESIS, TRANSPIRATION AND YIELD OF RAINFED BEANS WITH SUPPLEMENTAL IRRIGATION AND NITROGEN

摘要

The growth and yield of beans is the manifestation of the interaction genotype * environment through physiological processes. When the production of a crop is limited by water and nutrients and other supplies, it is expected that the effect of this limitation is observed in the first instance in these processes. Nunez et al. (1998) indicate that bean photosynthesis, stomatal conductance and yield under water stress are reduced. The magnitude of this response depends on the genotype (Acosta, 2009) Inbean cultivar Cacahuate72, Sanchez et al. (2000) report a rate of photosynthesis of 10-12 mu mol CO_2 m~(-2) s~(-1) and stomatal conductance of 200 and 180 mmol m~(-2) s~(-1) at the stage of growth and pod filling, respectively. Moreover, N is crucial inphotosynthesis (Sinclair and Horie, 1989) and bean yield (Escalante and Rodriguez, 2010). In addition, under water deficit conditions, plants with N may have osmotic adjustment allowing it to maintain cell turgor and thus less affected physiological processes (Smirnoff and Stewart, 1985). The aim of this study was to determine in beans of rainfed cv. "Cacahuate 72" of determinate growth habit type I, the effect of supplemental irrigation and nitrogen on the rate of photosynthesis, stomatal conductance, transpiration, water potential and its relationship to yield.