Trocas gasosas em plantas de alface cultivadas em solo com diferentes coberturas e sombreadas com agrotêxteis.

Abstract

Lettuce is a leafy vegetable with high nutritional value and great consumer acceptance. Its cultivation in regions with high levels of solar radiation and temperature may affect its growth and development due to a reduction in gas exchange, thus impactingthephotosynthetic process. In this sense, in order to mitigate the negative effects of soil- andclimate-related factors, it is necessary to adopt appropriate technologies that enhance thecultural management of this species. Therefore, the objective of this study was to evaluategas exchange in lettuce under different soil coverings and agrotextile colors. Theexperiment was carried out from October to December 2024 at the “Rolando EnriquesRibas Castellón” Experimental Farm of the Federal University of Campina Grande, inSão Domingos – PB. The curly lettuce hybrid cultivar Elba was used. Treatments werearranged in a randomized block design with a 3 × 4 factorial scheme, withfour replications, resulting from the combination of three soil coverings (bare soil, crushedcarnauba straw, and synthetic mulching with black plastic) and four types of agrotextile(white, red, yellow, and green). At data collection, variables related to plant gas exchangewere evaluated. Soil coverings and agrotextile colors significantly influenced lettuce gasexchange. Plants grown under carnauba straw also showed significant results, reflectingbetter performance in variables such as internal CO₂ concentration and leaf transpiration. Lettuce grown under black mulch stood out as the best soil cover in terms of physiological variables, promoting higher values for net photosynthesis rate, stomatal conductance, leaf transpiration, water use efficiency, and carboxylation efficiency. Regarding agrotextilecolor, the best results were observed in plants covered in red, yellow, and white, especially when combined with ground covers. Combinations of ground cover (mulchingor carnauba straw) with shading in white, red, and yellow provided greater physiological comfort to lettuce plants by reducing temperature extremes and improving water useefficiency