S-metolachlor e atrazine AFETAM A CINÉTICA DE ABSORÇÃO DE ÁGUA E A EMISSÃO RADICULAR DE SEMENTES DE MILHO: ANÁLISE DE IMAGEM

Abstract

Preemergent herbicides can have negative effects on maize seeds. The objective of this study was to model seed soaking curves through the processing of RGB imagery of maize seeds under the effect of concentrations of s-metolachlor + atrazine on both the soaking kinetics and primary root emission. Seeds were placed to soak in Petri dishes containing aqueous solutions of the herbicide for 114 hours containing s-metolachlor (290 g L-1) + atrazine (370 g L-1) with the concentrations: 0% (water only), 2%, 5%, 10%, 20% and 50%, based on the recommended dose (4.0 L of the commercial product per hectare). Images were systematically taken from a flatbed scanner with artificial light control. We adapted the red excess index to improve image segmentation. From the binary masks, the soaking curves for each herbicide concentration were obtained using estimates of seed intumescence in time. The soaking curves were described by fitting Peleg’s model. The herbicide concentration has significative effects on both the absorption rate and primary root emission, reducing them. Twenty percent, or more, concentration of s-metolachlor (290 g L-1) + atrazine (370 g L-1) in the aqueous solution can fully inhibit seed germination.