ECONOMIC WEED THRESHOLD OF MARANTA SOBOLIFERA PLANTS IN OFF-SEASON CORN

Abstract

Maranta sobolifera (Caetê) has tolerance to chemical management and has spread consistently on the agricultural areas of the western region of Paraná over the years. However, there is little information about its potential to interfere with the main agricultural crops. This study aimed to estimate the economic weed threshold (EWT) of M. sobolifera plants in commercial areas of production of off-season corn. There were losses in grain yield of up to 303.7 kg plant-1 of M. sobolifera. Considering an acceptable loss in grain yield of 614.05 kg ha-1, EWT estimates varied from 2.0 to 41.2 plants m-2 of M. sobolifera. In practice, these data can be used in no-till areas, where complementary control is necessary at the crop post-emergence (V4-V6), after desiccation of the area, to maintain weed density at tolerable levels until the end of the cycle. In addition, factors such as the use of less competitive hybrids, obtaining the maximum productive potential of the crop, increasing the value of the harvested product and the efficiency of chemical management (desiccation) and a reduction in the cost of control contribute to the reduction of the EWT and make the adoption of management practices of M. sobolifera more profitable in off-season corn.