SOUSA, P. F. N.; http://lattes.cnpq.br/0975512026353084; SOUSA, Pedro Francisco do Nascimento.
Resumo:
Hydroponic cultivation has been an alternative to the limited availability of water with low
electrical conductivity for irrigation in the Northeastern semi-arid region, which has restricted
food production, making it necessary to use strategies to reduce the effects of saline stress on
plants. Among the alternatives, the foliar application of salicylic acid stands out. In this
context, the objective of this study was to evaluate the effects of foliar application of salicylic
acid in mitigating effects of salt stress in gas exchange, chlorophyll a fluorescence,
photosynthetic pigments, and growth of hybrid okra 'Canindé' in a hydroponic system. The
study was carried out in a greenhouse, in Pombal - PB, using the hydroponic cultivation
system the Nutrient Laminar Flow Technique - NFT. The experimental design used was
completely randomized in a split-plot scheme, with four levels of electrical conductivity of
the nutrient solution - ECsn (2.1, 3.6, 5.1, and 6.6 dS m-1) considered as plots and four
concentrations of salicylic acid - AS (0, 1.2, 2.4, and 3.6 mM), as the subplots, with four
replicates and two plants per plot. Salicylic acid at a concentration of 3.6 mM minimized the
effect of nutrient solution salinity on chlorophyll a fluorescence and promoted an increase in
the synthesis of chlorophyll b in okra plants. Nutrient solution salinity above 2.1 dS m-1
negatively affected gas exchange, relative water content, photosynthetic pigments, growth and
increased electrolyte leakage in the leaf blade of okra plants.