Physiological responses of lima bean subjected to salt and water stresses

Respostas fisiológicas da cultura da fava submetida a estresse salino e hídrico

ABSTRACT

Under water deficit and/or salt stress conditions, crops suffer from several physiological disturbances, which lead to the reduction in growth and, consequently, decreases in their yields. Thus, the objective of this study was to evaluate the physiological responses of lima bean, cultivar Espírito Santo, under different irrigation water salinity associated to two water regimes. The experiment was carried out in the experimental area of ​​the Universidade Federal do Ceará, Brazil, from September to November 2017, and it was carried out in pots in full sun, under a completely randomized design in split plots, where water salinities (1.1, 2.1, 3.1, 4.1 and 5.1 dS m^-1) were considered as the plots, and the treatments of water regime (50 and 100% of the reference evapotranspiration - ETo) were considered as the subplots. At 45 days after sowing, leaf gas exchanges and relative index of total chlorophyll (SPAD index) were evaluated. In general, the increase of salt concentration in irrigation water causes reductions in the physiological responses of lima beans. Under a water regime of 50% ETo, the instantaneous and intrinsic water use efficiency is higher.

Key words:
Phaseolus lunatus L.; photosynthesis; water quality; water deficit