Fertilizante à base de fungos micorrizos no cultivo de algodoeiro de fibra colorida em solo salinizado.

Abstract

In Northeast Brazil, cotton farming is an agricultural activity of great socioeconomic importance. However, the salinity of water sources and soil is a challenge for agricultural production in this region. To mitigate the impacts of saline stress on plants in salinized soils, it is necessary to develop appropriate technologies, notably the application of mycorrhizal fungi. The objective was to evaluate the morphophysiology and production of colored fiber cotton grown in salinized soil under different concentrations of fertilizer based on mycorrhizal fungi. The experiment was conducted in pots adapted as drainage lysimeters and developed under field conditions at the Federal University of Campina Grande, Pombal-PB Campus, using a randomized block design in a 5 × 4 factorial scheme, referring to five levels of electrical conductivity of the saturation extract - ECes (3.7; 4.9; 6.1; 7.3 and 8.5 dS m-1) and four concentrations of mycorrhizal fungus (0 - Control; 1.5; 2.5 and 4.5 g L-1). Irrigation was carried out according to the principle of drainage lysimetry. Soil salinity starting at 5.0 dS m-1 inhibited growth, gas exchange, chlorophyll content, and production of colored fiber cotton. Concentrations of up to 2.5 g L-1 of mycorrhizal fungi attenuated the effect of saline stress on growth, physiology, and cotton production under EC50 levels up to 5.0 dS m-1. The use of mycorrhizal fungi can be an efficient strategy for producers in arid and semi-arid regions, commonly affected by excess salts in the soil.