Morphophysiology and production of naturally colored cotton under salt stress and foliar application of salicylic acid

ABSTRACT: Cultivation of naturally colored cotton is an alternative to add value to the crop in the northeast region of Brazil, but it is necessary to adopt strategies capable of attenuating the effects of salt stress, increasingly common in this region. In this context, the present study evaluated the morphophysiology and production components of naturally colored cotton cv. ‘BRS Jade’ irrigated with saline water and under foliar application of salicylic acid. The experimental design was randomized blocks, in a 5 × 5 factorial scheme, referring to five levels of electrical conductivity of irrigation water - ECw (0.3, 1.8, 3.3, 4.8, and 6.3 dS m-1) and five concentrations of salicylic acid - SA (0, 1.5, 3.0, 4.5, and 6.0 mM), with three replicates. Irrigation water up to 6.3 dS m-1 did not cause losses greater than 10% in the morphophysiology of colored cotton. Application of salicylic acid at a concentration of 6.0 mM increased CO2 assimilation rate, but affected negatively the biomass accumulation, lint cotton weight, bract dry mass, and total number of bolls of colored cotton cv. ‘BRS Jade’. Salicylic acid did not mitigate the effects of salt stress on the morphology and lint production of naturally colored cotton cv. ‘BRS Jade’ at 100 days after sowing.