Integrating Herbicide‐Resistant Corn Technology in a Kura Clover Living Mulch System

Abstract

Previous research has shown that with adequate suppression, kura clover (Trifolium ambiguum M. Bieb.) can be managed as a living mulch in corn (Zea mays L.); however, significant yield loss was observed in some environments. This study evaluated two herbicide‐resistant corn hybrids at three levels of kura clover living mulch suppression over multiple environments. In 1999 and 2000 near Arlington and in 2000 near Lancaster, WI, glyphosate [N‐(phosphonomethyl)glycine]‐resistant corn (Roundup Ready corn, RRC) and glufosinate [2‐amino‐4‐(hydroxymethylphosphinyl) butanoic acid]‐resistant corn (Liberty Link corn, LLC) hybrids were planted where kura clover had been (i) killed for monocrop corn, (ii) strongly suppressed with glyphosate and dicamba (3,6‐dichloro‐2‐methoxybenzoic acid), or (iii) lightly suppressed with only glyphosate. Suppressed kura clover also had a 25‐cm clopyralid (3,6‐dichloro‐2‐pyridinecarboxylic acid) plus dicamba‐killed band into which corn was planted. Subsequent postemergence applications of glyphosate or glufosinate herbicide were made for each hybrid. Corn whole‐plant yield ranged from 17.3 to 19.9 Mg ha−1, and grain yield ranged from 10.8 to 12.3 Mg ha−1. Yield of whole‐plant and grain across both corn hybrids did not differ between monocrop corn and corn in strongly suppressed kura clover. Whole‐plant yield of monocrop corn was 8 to 11% greater and grain yield 8 to 9% greater than in lightly suppressed kura clover, respectively. Both hybrids had similar corn whole‐plant yield, but LLC grain yield was lower than that of RRC. Kura clover recovery in the season following corn production was similar among living mulch suppression treatments by mid‐July. Herbicide‐resistant corn technology allowed for consistent kura clover living mulch management with little or no whole‐plant or grain yield loss.

Maize performance in a kura clover living mulch under drought conditions

“…Individual plots measured 3 by 12 m and each treatment combination had four replications. Row establishment treatments included rotary zone tillage (RZT), shank striptillage (ST), and banded herbicides (BH), and were chosen based on previous work and their practicality for farmers managing a KCLM (Affeldt et al, 2004;Alexander et al, 2019a). Additional details regarding the row establishment treatments are provided in Table 1.…”

“…Most of the early work with KCLM systems utilized herbicides (Albrecht & Sabalzagaray, 2006;Zemenchik et al, 2000). Affeldt et al (2004) utilized broadcast glyphosate and dicamba and banded dicamba and clopyralid before planting to chemically suppress kura clover in the row and interrow zones. This suppression regime resulted in no difference between maize yield in monocrop and KCLM treatments.…”

Corn (Zea mays L.) Production in Living Mulch Systems Using White Clover (Trifolium repens L.) under Different Nitrogen Fertilization Rates

“…In addition, it is likely that legume LM alone will not provide sufficient N necessary for optimum productivity in corn [19]. The authors of [20] applied N at 45 kg/ha between the V3 and V5 stages to avoid resource limitation for corn growth, and the authors of [21] observed that side dressing N to LM grown with corn increased the whole-plant corn yield.…”