Interaction between water salinity and biostimulant in the initial growth of physic nut

The objective of this study was to evaluate the interaction between salinity levels of the water and the use of biostimulant in initial growth of physic nut plants. The experiment was conducted during the period of August and October 2012, at the Federal Rural University of Semi-Arid, at Mossoró, RN, adopting a completely randomized design in a 2 x 4 factorial arrangement. The treatments consisted of the combination of two levels of salinity of irrigation water (0.5 and 5.0 dS m^-1) and four intervals of application of biostimulant (I1 - Absence; I2 - 7 days; I3 - 14 days; I4 - 21 days). The commercial phytoregulator Stimulate® 10X was used, in the standard concentration of 18 mL L^-1 solution. Height, stem diameter, main root length, number of leaves, leaf area, dry weight of leaf, stem and root , total dry weight and ratio of dry mass of aerial parts to dry mass of root were evaluated. Salt stress caused a reduction in all variables and inhibited the effect of the biostimulant in the used intervals. Stimulate® 10X did not inhibit the deleterious effect of salinity of irrigation water on the initial growth of physic nut plants.

Jatropha curcas L.; saline stress; phytoregulator