AGRONOMIC DEVELOPMENT OF RADISH UNDER DIFFERENT SHADING LEVELS

Abstract

This study evaluated the effect of different shading levels on the agronomic performance of radish (Raphanus sativus L.) under the edaphoclimatic conditions of the Western Amazon. The experiment was conducted at the Federal University of Acre using a completely randomized design, with four shading levels (0%, 35%, 50%, and 65%), ten replicates, and one plant per experimental unit. The number of leaves, total fresh mass, shoot fresh and dry mass, root fresh mass, and root diameter were evaluated. After verifying the normality of residuals and homogeneity of variances, the data were subjected to analysis of variance and, when appropriate, polynomial regression analysis. Shading significantly affected all variables except the number of leaves. Root fresh mass and root diameter showed quadratic responses, with estimated maximum values at 17.79% and 21.23% shading, respectively; however, these levels were not directly evaluated. Under 65% shading, the lowest values of root fresh mass (6.31 g plant⁻¹) and root diameter (19.47 mm) were observed. It is concluded that intense shading impairs tuberous root formation, whereas the agronomic potential of light shading should be validated through the direct evaluation of intermediate shading levels.