Reducing Grain Sorghum (Sorghum bicolor L. Moench) Injury From Postemergence Application of Mesotrione With Dicamba

Ralph R. Hale,Taghi Bararpour,Gurbir Singh,Gurpreet Kaur

doi:10.5539/jas.v12n12p1

Abstract

Weed management in grain sorghum is limited by the number of herbicide options. A two-year (2017-2018) field study was conducted at the Mississippi State University Delta Research and Extension Center, in Stoneville, MS to evaluate the response of grain sorghum to mesotrione application alone or when tank-mixed with dicamba at the two-leaf and four-leaf growth stage of sorghum. Mesotrione was applied at 0.07 and 0.105 kg ai ha-1 alone or was tank-mixed with dicamba at 0.28 kg ae ha-1. Significant injury to grain sorghum from all herbicide treatments was observed compared with the untreated check. Increase in mesotrione application rate increased injury to grain sorghum from 14 to 19% at two-leaf and from 10 to 24% at the four-leaf stage by 4 weeks after application (WAA) in 2017. Adding dicamba to mesotrione reduced grain sorghum injury in both years. At 4-leaf sorghum application stage, mesotrione applied at 0.07 kg ha-1 resulted in greater grain yield than all other herbicide treatments, except mesotrione (0.105 kg ha-1) + NIS in 2017. Our results indicate that adding dicamba to mesotrione safes grain sorghum from injury caused by mesotrione alone.

Highlights

In 2017, the injury to grain sorghum assessed on 1 August and 17 August was affected by the interaction of application timing and herbicide treatments as well as by the main effects of application timing and herbicide treatments (Table 4)
Grain sorghum showed greater injury to mesotrione application at 4-leaf growth stage (15%) than at 2-leaf growth stage (10%) (Figure 1A)
Grain sorghum injury increased from 14% to 19% as mesotrione application rate at 2-leaf growth stage increased from 0.07 kg ha-1 to 0.105 kg ha-1 (Figure 1A)

Summary

Introduction

Moench) is an important cereal crop grown in the United States. In 2019, U.S harvested 4.6 million ha of grain sorghum (USDA-NASS, 2020). Like crop rotation, are important for weed control in grain sorghum along with incorporating herbicide programs (Brown, Al-Khatib, Regehr, Stahlman, & Loughin, 2004). Unlike corn (Zea mays L.), cotton (Gossypium hirsutum L.), or soybean Merr.), there are limited options for weed control in grain sorghum

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