Control of johnsongrass (Sorghum halepense) with nicosulfuron in maize at different planting patterns

Abstract

This study was conducted in 2005 and 2006 at Research Farm of Tehran University to investigate the influence of four nicosulfuron doses (35, 70, 105 and 210 g a.i. ha-1) on the performance of maize and its efficacy in the control of johnsongrass. The experiment was designed as complete randomized block with three replications. All plots that received nicosulfuron had significantly higher maize grain yield than the unweeded control at both planting patterns in both years. Maize grain yield in the weeded control was similar to plots that received nicosulfuron at 35-210 g a.i. ha-1 at single row planting pattern (SR) in 2006, 70-210 g a.i. ha-1 at double row planting pattern (DR) in 2005 and 35 g a.i. ha-1 at DR planting pattern in 2006. The unweeded control had significantly higher weed shoot and rhizome biomass than all other treatments at both planting pattern in both years. Johnsongrass rhizome biomass in the weeded control was similar to that in all nicosulfuron-treated plots. In general at DR planting patterns johnsongrass biomass in both years and at all doses was less than that at SR planting pattern. The findings of this study show that nicosulfuron is a suitable Postemergence (POST) herbicide for johnsongrass control in maize. © 2007 Asian Network for Scientific Information.