Morfofisiologia e produção de quiabeiro ‘Valença’ cultivado com águas salinas e adubação silicatada.

Abstract

Excess salts in water and / or soil are a critical factor that severely affects physiology and growth, limiting crop production in the Brazilian Northeast, and it is necessary to adopt strategies that reduce the effects of saline stress on plants, among them, the fertilization with silicon stands out. To evaluate the gas exchanges, growth and production of okra cv. Valença due to the irrigation with saline waters and doses of silicon.The experiment was conducted under field conditions in the municipality of Pombal-PB. A randomized complete block design was used in a 5 x 2 factorial scheme, with five levels of water conductivity (0.3, 1.0, 1.7, 2.4 and 3.1 dS m-1) and two doses of silicate fertilization (100 and 200 g silicon plant-1 ) with four replicates. The data were submitted to analysis of variance by the F test and when significant were performed regression analysis for the factor saline levels and test of comparison of means (Tukey at 0.05 level of probability) for silicon doses and, when there was interaction Significant among the factors, the DS factor unfolded within NS using the SISVAR-ESAL statistical software. Saline stress reduced the rate of CO2 assimilation and the instantaneous efficiency of carboxylation, growth, and yield of okra plants. Saline stress reduced the rate of CO2 assimilation and the instantaneous efficiency of carboxylation, growth, and yield of okra plants. The increase in intercellular CO2 concentration in the sub-static camera in okra plants did not promote an increase in the CO2 assimilation rate, emphasizing non-stomatal origin effects as limiting factors. The intrinsic efficiency in water use and the average weight of okra fruits were not influenced by irrigation with salt water and silicon doses. The supply of silica at the dose 200 g plant-1 decreased the deleterious effect of salt stress on stomatal conductance and leaf area of okra at 65 days after sowing.