Growth and production of colored fiber cotton (Gossypium hirsutum L.) subjected to salt stress and potassium fertilization

Abstract

Temporal and spatial variation of rainfall in semiarid regions may lead to an increase in the concentrations of salts present in irrigation water, and it is necessary to adopt techniques to reduce the negative effects of salts on plants. Thus, the present study aimed to evaluate the growth and production of colored cotton cv. BRS Topázio as a function of irrigation using water with different levels of salinity and potassium doses. The experiment was carried out in pots adapted as lysimeters under greenhouse conditions, using a non-saline Neossolo Regolítico (Entisol) of sandy texture. The experimental design was randomized blocks, with 4 replicates, with treatments distributed in a 4 x 4 factorial scheme, corresponding to four levels of saline irrigation water electrical conductivity (1.5; 3.0; 4.5 and 6.0 dS m-1) and four potassium doses (50; 75; 100 and 125% of the recommendation), with a dose of 100% corresponding to 150 mg K2O per kg-1 of soil. Irrigation using water of electrical conductivity (saline) above 1.5 dS m-1 negatively affected the growth and production of cotton cv. BRS Topázio, and cotton seed weight was the most sensitive variable. Potassium doses above 50% of the recommendation in interaction with salinity reduced the height and leaf area of cotton cv. BRS Topázio.