Propelled abrasive grit applications for weed management in transitional corn grain production

Mauricio Erazo-Barradas,Claire N Friedrichsen,Sharon A Clay,Frank Forcella,Dan Humburg

doi:10.1017/s174217051700031x

Mauricio Erazo-Barradas, Claire N Friedrichsen + Show 3 more

Open Access

https://doi.org/10.1017/s174217051700031x

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Abstract

AbstractWeed control is challenging to farmers who are transitioning from production systems that use synthetic herbicides to organic systems. A 2-year field study examined air-propelled corncob grit abrasion for in-row weed control efficacy and effect on corn yield. Grit was applied based on corn vegetative developmental stages with one (V1, V3 or V5), two (V1 + V3, V1 + V5, or V3 + V5), or three (V1 + V3 + V5) applications. Flame-weeding or cultivation was used after the V5 application for between-row weed control. Grit applications decreased in-row weed densities by about 60% (α = 0.05) and biomass up to 95% (α = 0.001). Between-row treatments provided similar control, and reduced weed biomass by 55% in 2013 (α = 0.01) and 86% (α = 0.001) in 2014. In-row grit treatments increased corn yield up to 44%, and yield was more influenced by in-row weeds than between row weeds. These results indicate that abrasive corncob grit for in-row weed control, supplemented with cultivation or flaming, can reduce weed biomass substantially and help maintain corn yield. However, timing and frequency of grit application need further refinement based on weed growth as influenced by climate, as treatments at similar corn growth stages did not consistently provide adequate weed control between years.

Highlights

Before the discovery and use of synthetic auxin-like herbicides in the late 1940s (Vats, 2015), farmers relied on numerous non-chemical methods for weed control
Herbicide use reduced the labor needed for farming, increased long-term crop productivity (Aktar et al, 2009), and helped increase the adoption of zeroor reduced-tillage production systems (Lee et al, 2014)
Alternative weed control strategies are desirable for conventional growers due to increases in weed biotypes resistant to multiple herbicides (Heap, 2017), the lack of new mode-of-action herbicides (Duke, 2012), environmental impacts of most weed management systems, (Barbash et al, 1999; Johnson, 2004) and general consumer concerns (Greene, 2016)

Summary

Introduction

Before the discovery and use of synthetic auxin-like herbicides in the late 1940s (Vats, 2015), farmers relied on numerous non-chemical methods for weed control. In field experiments, Forcella (2012) reported that two applications of air-propelled corncob grit aimed at the row, combined with inter-row cultivation reduced weed presence in corn and increased yield. Erazo-Barradas (2016) demonstrated that in certified organic silage corn, early in-row grit applications (V1 and V3 stages of corn growth) effectively controlled weeds and maintained high crop yields, but later applications (V5 and V7) reduced corn yields due to prolonged crop–weed interference.

Results

Conclusion