Produção de pimentão sob diferentes estratégias de irrigação com e sem cobertura do solo, no semiárido baiano

Abstract

Bell peppers represent an economically important vegetable crop that adapts well to semiarid conditions. Due to the irregular rains and low water availability in the semiarid region of Brazil, irrigation management there must focus on the rational use of water. Strategies that promote efficient water use must therefore be employed, including Regulated Deficit Irrigation RDI, either isolated, or in combination with plastic mulching. The production, physiological, and growth characteristics of bell pepper plants were evaluated using different irrigation strategies in systems with or without plastic mulching during the period between March and December/2016 in the semiarid region of the municipality of Vitória da Conquista-BA. An experimental scheme of plots randomly subdivided into subplots (with four repetitions) with and without plastic mulching soil covering was used in 10 different irrigation strategy combinations: L1, 125% of the ETc; L2, 100% of the ETc; L3, 75% of the ETc; L4, 50% of the ETc both in the development (PI) and production phase (PII); L5, RDI with 50% of the ETc in PI and 100% of the ETc in PII; L6, RDI with 100% of the ETc in PI and 50% of the ETc in PII; L7, RDI 75% of the ETc in PI and 100% of the ETc in PII; L8, RDI 100% of the ETc in PI and 75% of the ETc in PII; L9, RDI 125% of the ETc in PI and 75% of the ETc in PII; L10, RDI 75% of the ETc in PI and 125% of the ETc in PII. The irrigation systems were evaluated during the experiments through uniformity tests. The plants were monitored in terms of their physiological characteristics (chlorophyll fluorescence; leaf area index; chlorophyll index), phtyo-technical characteristics (plant height, numbers of leaves), fruit characteristics (length, diameter, mass, skin thickness), and production characteristics (production and water use). The Christiansen Uniformity Coefficient (CUC) was 96.51%, the Uniformity Distribution Coefficient (CUD) was 92.80%, and the Coefficient of Statistical Uniformity (CUE) was 88.65%. The chlorophyll indices encountered did not differ in terms of the use or non-use of soil cover in the different irrigation strategies. The application of a blade equivalent to 50% of the evapotranspiration of the culture, with mulching, was found to generate the greatest water use efficiency and productivity.