Interference of Volunteer Corn from Different Origins and Emergence Time on Soybean Yield and Stress Metabolism

C Piasecki,M.A Rizzardi,J Schons,C Langaro,A Caverzan

doi:10.1590/s0100-83582019370100140

C Piasecki, M.A Rizzardi + Show 3 more

Open Access

https://doi.org/10.1590/s0100-83582019370100140

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Abstract

ABSTRACT: Volunteer corn occurrence with soybean is favored by the glyphosate-resistant (GR) corn cultivation preceding soybean and no-tillage systems. Volunteer corn interference causes significant losses in soybean grain yield. The levels of crop losses change with the corn density, origin, and time of emergence. High levels of weed interference in crops can result in the production of reactive oxygen species and lead to the occurrence of oxidative stress. The objectives of this study were to evaluate the effects of interference of (1) different origins (individual plants and clumps) and times of emergence of volunteer corn on soybean growth, yield components, and grain yield loss; and (2) if the volunteer corn interference causes oxidative stress in soybean. Field experiment and laboratory analyses were performed. The evaluated variables were soybean yield components, grain yield, hydrogen peroxide - H2O2 content, and antioxidant enzyme superoxide dismutase - SOD, catalase - CAT, and ascorbate peroxidase - APX activities. Volunteer corn interference reduced the yield components and soybean yield. The highest yield losses were observed with volunteer corn clumps regarding individual plants. The interference of volunteer corn emerged 10 days before or on the same day as soybean caused the greater yield losses than those emerged 10 days after, independently of its origin. The content of H2O2 and enzyme SOD, CAT and APX activities changed in soybean leaves in response to the interference of volunteer corn plants and clumps. However, the results indicate that the volunteer corn interferences does not cause oxidative stress in soybean.

Highlights

Volunteer corn (VC) originate from unharvested seeds or those lost during poor harvest process
A significant interaction between factors was observed for soybean height at 20 and 62 days after emergence (DAE), whereas significant differences in corn height were only observed between different emergence times (Table 1)
In this evaluate and was more strongly affected by the presence of clumps compared with individual plants and by VC emerged 10 days before or on the same day as soybean compared with 10 days after soybean

Summary

Introduction

Volunteer corn (VC) originate from unharvested seeds (abandoned areas) or those lost during poor harvest process. These seeds lost occur individually, which produce individual plants, or as rachis segments or whole ears, producing clumps (i.e., several plants at a single point) (Beckett and Stoller, 1988). The interference of VC in density lower than one plant or clump m-2 has been reported to causes significant decreases in soybean grain yield (Andersen et al, 1982; Chahal and Jhala 2016; Piasecki et al, 2018a). Piasecki et al (2018a) reported that when densities of individual plants and clumps (emerged together with the crop) increased from 0.5 to 12 m-2 reduce the soybean (0.5 m row spaced) yield from 22.2 to 91.9%, and 46.4 to 100%, respectively, in South of Brazil The interference of VC in density lower than one plant or clump m-2 has been reported to causes significant decreases in soybean grain yield (Andersen et al, 1982; Chahal and Jhala 2016; Piasecki et al, 2018a). Piasecki et al (2018a) reported that when densities of individual plants and clumps (emerged together with the crop) increased from 0.5 to 12 m-2 reduce the soybean (0.5 m row spaced) yield from 22.2 to 91.9%, and 46.4 to 100%, respectively, in South of Brazil

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