Potassium fertilization in the cultivation of colored cotton irrigated with saline water

ABSTRACT The objective of this study was to evaluate growth, flowering and production components of the cotton cv. ‘BRS Topázio’ irrigated with water of different salinity levels and potassium (K) doses in the soil. The research was conducted in a greenhouse. The experiment was set in a randomized complete block design with four replicates, in 4 x 4 factorial arrangement with 4 levels of irrigation water salinity (1.5, 3.0, 4.5 and 6.0 dS m-1) and four K doses (50, 75, 100 and 125% of the recommendation); the dose of 100% corresponded to 150 mg K2O kg-1 of soil. Irrigation water salinity reduced stem diameter, plant height, number of leaves and leaf area of the cotton cv. ‘BRS Topázio’. Leaf area at 53 DAS was the most affected variable. The highest K dose associated with increased salinity of the irrigation water caused a more deleterious effect on the number of leaves and leaf area at 108 DAS. Progressive increases in irrigation water salinity proportionally increased flower abortion rate and, consequently, reduced the total number of bolls and seed weight of cotton