Water-retaining polymer in okra cultivation under water replacement levels

ABSTRACT The cultivation of okra [Abelmoschus esculentus (L.) Moench] has potential for expansion in Northeastern Brazil. However, irregular precipitation, associated with high evapotranspiration rates, is a limiting factor for agricultural development. In this context, the use of water-retaining polymers stands out as a promising alternative due to their capacity to retain water and ensure favorable conditions for plant growth. Thus, the present study aimed to evaluate the effects of a water-retaining polymer on the growth, production, and fruit quality of okra under different water replacement levels. The experiment was conducted in a greenhouse at CCTA/UFCG, Pombal Campus, PB, Brazil. The experimental design was a randomized block in a 5 x 4 factorial scheme, corresponding to five water replacement levels (40, 60, 80, 100, and 120% of the actual evapotranspiration - ETr) and four doses of a water-retaining polymer (0, 1.0, 2.0, and 3.0 g L-1), with three replications. A water replacement level of 80% ETr resulted in the greatest growth and production of okra cv. Carcará. Both deficit and excess water replacement caused growth inhibition and a decrease in the number of fruits. The application of the water-retaining polymer at a dose of 3.0 g L-1 had a beneficial effect on the growth, fresh mass, and mean diameter of the fruits, being indicated for okra cultivation in semiarid areas. Irrigation with 40% ETr combined with a 1.3 g L-1 of the water-retaining polymer increased the ascorbic acid content in the fruits of okra cv. Carcará.