LAUSR

ABSTRACT The use of screened structures is an alternative for reducing light, creating an ideal microclimate for vegetable development. In this sense, the objective of this research was to evaluate the effect of shading caused by the protected environment on the dynamics and period of weed control in organic arugula crops. Two experiments were carried out using a randomized block design with three replications in a split-plot scheme. The first experiment was conducted under full light conditions, and the second experiment was conducted in a shaded environment with a 35% reduction in light. The Digitaria horizontalis Willd and Amaranthus spinosus L. having the highest density in the uncovered system and the protected environment, respectively. The lack of weed control reduced arugula productivity by 52 and 80% in systems with and without a protected environment, respectively. The critical interference prevention period (CIPP) for arugula in an uncovered environment was 8–29 and 8–26 days after transplant (DAT), considering an acceptable production reduction of 2.5 and 5%, respectively. The protected environment reduced the CIPP of arugula to 20–39 and 20–31 DAT for acceptable production reductions of 2.5 and 5%, respectively. The use of the protected environment changed the dynamics of the species and reduced the period of weed control in organic arugula by 3 and 8 days, considering an acceptable production reduction of 2.5 and 5%, respectively.