PHYSIOLOGICAL PERFORMANCE OF COMMON BEANS SUBMITTED TO DEFICIT IRRIGATION AND BIOSTIMULANTS

The common bean is a sensitive plant to the effects of water deficit and physio-biochemical alterations which influence the yield are observed. Vegetal biostimulants are inputs which present potential to mitigate the effects of water deficit on crop development. This paper aimed to evaluate the physiological and biochemical impact of water deficit on common bean and the potential of applying biostimulants as a mechanism to tolerate the stress. The assay was conducted in an agricultural greenhouse in Botucatu-Brazil, the pots were disposed in a split-plot design in randomized blocks, with four replications. The treatments in the plots corresponded to the water content tension, control (-10 kPa) and water deficit (-40 kPa), in the subplots the biostimulants treatments (B1- control; B2- Bacillus amyloliquefaciens BV; B3- Bacillus amyloliquefaciens BV 03 + algae extract Ascophyllum nodosum). The analyzed variables were: leaf pigments, gas exchanges, total soluble proteins, L-proline, specific activity of the enzyme superoxide dismutase, shoot dry matter and crop yield. The water deficit affected negatively all parameters evaluated and the biostimulants in the tested form, did not show efficiency in helping the plants to tolerate stress due to drought. We suggest new studies to prove the efficiency of biostimulants for field applications.