Imazapic interaction and mobility in soil cultivated with sugarcane in northeast Brazil

Abstract

In the plantation of sugarcane, Imazapic has used pre- or post-emergence, alone or in combination with other herbicides. When applied to the soil in pre-emergence, Imazapic can undergo the sorption, leaching and/or degradation processes due to physical, chemical and biological effects, besides being absorbed by weeds. The objective of this work was to evaluate the interaction and mobility of the Imazapic herbicide in the soil where the soil columns with a dystrophic Yellow Ultisol (YUd) and a dystrophic Red-Yellow Oxisol (RYOd) from northeastern Brazil were used. The higher adsorption potential of the RYOd is associated with higher clay content, higher Fed and Feo concentrations, and soil acidic pH. The CDE – 2 sorption sites model adequately represented the experimental data from the Imazapic breakthrough curves to the RYOd and YUd soils. From the Kd partition coefficients for RYOd and YUd, high values of the GUS index (5.94 and 7.04, respectively) were calculated, confirming the high leaching potential of the Imazapic molecule in these soils.

Evaluation of imazapic and flumioxazin carryover risk for Carinata (Brassica carinata) establishment

“…, where y is damage in percent; x is application interval (months before planting); a, b, and c are the intercept, the linear coefficient, and the quadratic coefficient, respectively; x 0 is the critical value occurring at the intersection of the quadratic response; and y 0 is the plateau. These results are complementary to Figure 3 imazapic leaching possible, especially in coarse-textured soils with low organic matter content (de Assis et al 2021;Neto et al 2017). Similarly, there was higher imazapic recovery from soils in Jackson Springs (sand-textured soils and higher precipitation values) compared with Clayton (Table 1; Figure 1).…”

“…The results indicate that carryover issues might be noticeable during establishment or later. This latter scenario is likely to occur due to: (1) the persistence and mobility reported for the ALS-inhibitor herbicide family (de Assis et al 2021;Marchesan et al 2010);…”