Selectivity of herbicides for sugarcane Plene® system in pre and post-emergence

Abstract

The Plene^® system is a new cane planting technology that came to simplify and streamline the initial phase of planting, since it employs mini-stalks previously treated. However, there is a lack of information on the selectivity of herbicides in this new system and, due to this, it was aimed to evaluate the phytotoxicity of herbicides commonly used in the traditional cultivation of sugarcane for the control in pre-and post-emergence of weeds when employed in Plene^® system. Two experiments have been developed, one with application in pre-emergence and another with post-emergence. In both experiments it were planted two stalks per pot (5 L), previously filled with mixture composed of four parts of soil (extracted from the arable layer of Red Oxisol) and one portion of filter cake. After planting the first experiment, it was performed herbicide applications in pre-emergence (imazapic, sulfentrazone, ametryn, isoxaflutole, tebuthiuron, amicarbazone, mesotrione, and a check without application). For the second experiment, the applications of herbicides in post-emergence were performed at 14 days after plant emergence, and the treatments consisted of sulfentrazone, ametryn, isoxaflutole, amicarbazone, ametryn + clomazone, diuron + hexazinone, and a check without application. Treatments phytotoxicity evaluations were performed using visual scale. At the end of the experiments, it was conducted evaluations of plant height, number of tillers and leaves. In addition, it was determined the dry mass of leaves, stem, root, tholes, and it was recorded the number of regrowth in each pot after ten days of the cane plant cutting. The herbicides sulfentrazone, ametryn, tebuthiuron, amicarbazone, and mesotrione were selective to sugarcane 'SP81-3250' in Plene^® system when applied in pre-emergence, while ametryn, sulfentrazone, ametryn + clomazone, and diuron + hexazinone (468 g kg^-1 + 132 g kg^-1) were selective for post-emergence.