The objective of this study was to evaluate the interaction between salinity levels of the water and the use of biostimulant (Stimulate®) in the initial development stage of cowpea plants. The sowing of seeds was done in pots, using as a substrate Alfissol and two plants per pot. The experimental design was completely randomized in a 2 x 7 factorial scheme. The treatments consisted of combination of two salinity levels (0.5 and 5.0 dS m-1) with seven biostimulant application forms (without application, seed treatment, sprinkled 20 days after sowing (DAS), sprinkled 40 DAS, seed treatment + sprinkled 20 DAS, seed treatment + sprinkled 40 DAS and sprinkled 20 and 40 DAS). Two non destructive evaluations (20 and 40 DAS) and one destructive evaluation (60 DAS) were performed. Plant height, number of leaves, leaf area, and dry mater of leaves, stem and aerial parts were evaluated. All parameters were influenced by salinity. The biostimulant in the adopted forms of application did not render any improvement on plant development when submitted to saline stress. The salinity inhibited the beneficial effects of the biostimulant on the growth of the cowpea plants therefore, the use of plant growth regulator is not feasible in plants grown under salt stress.
Vigna unguiculata; saline stress; plant regulators
