With the adoption of the Xtend® technology growers began to report reduced control levels of weedy grasses when applying tank-mixes of glyphosate and dicamba. Therefore, research was conducted at the Delta Research and Extension Center in Stoneville, MS from 2019 to 2021 to examine influence of herbicide mixtures with dicamba, as well as carrier volume and nozzle type. Results indicated barnyardgrass control 14 and 28 DAT was greatest with glyphosate alone. Control was not different when DGA or BAPMA dicamba or 2,4-D choline were mixed with glyphosate. At 28 DAT, barnyardgrass control was 15 to 18% lower with herbicide mixtures compared with glyphosate alone. Barnyardgrass control with glyphosate plus dicamba was not decreased by drift-reducing nozzles. Carrier volume of > 94 L ha-1 provided greater control of barnyardgrass compared to 47 L ha-1. These results indicate potential of reduced barnyardgrass control with glyphosate plus dicamba.

Optimal plant populations are critical in achieving high rice yields. The purpose of this research was to investigate yield penalties associated with inadequate, non-uniform plant populations for modern rice cultivars. Research was conducted at the Delta Research and Extension Center in Stoneville, MS, in 2019, 2020 and 2021. In one study, inbred, herbicide-resistant ‘CL153’ was drill-seeded at 73-18 kg ha-1 after being mixed with inbred, herbicide-susceptible ‘Rex’ at 0-55 kg ha-1. Likewise, hybrid, herbicide-resistant cultivar ‘CL XL7521’ was seeded at 29-8 kg ha-1 mixed with hybrid, herbicide-susceptible ‘XP753’ at 0-21 kg ha-1. At the two- to three- leaf growth stage, imazamox was applied to eliminate ‘Rex’ and ‘XP753’ in their respective studies to achieve the target plant population (TPP). Results indicate that when plant populations are reduced up to 30% in both inbred and hybrid cultivars, grain yields should be comparable if not greater than an adequate, uniform plant population.