Interaction between pesticides applied alone or in mixtures in corn

Abstract

The objective of this work was to evaluate the selectivity of herbicides applied alone or in tank mix, and also of combinations of different classes of pesticides (fungicides, herbicides and insecticides) on corn. An experiment was installed in the 2017/18 crop to assess herbicide selectivity, and repeated in 2018/19. The second experiment aimed to assess the selectivity of mixtures of different classes of pesticides, and was installed only in 2017/18. The experimental design adopted in the tests was randomized blocks, with four replicates. In each trial, a total of 16 treatments were evaluated, plus a control. At 7, 14 and 21 days after the application of treatments the phytotoxicity to corn was evaluated and the yield components and grain yield were determined. Herbicides caused low levels of injury to the corn plants, with small variations in yield components, and affected crop yield differently. The mixtures of pesticides promoted low phytotoxicity, affected yield components inconsistently and caused changes in corn yield. Although these herbicides and other pesticides are registered for use in corn crops, application alone or in tank mix of certain molecules can cause losses in grain yield.

Keywords:

• Herbicide
• fungicide
• insecticide
• tank mixture
• Zea mays
• selectivity
• phytotoxicity
• grain yield
• combinations

Data available on request from the authors

The data that support the findings of this study are available from the corresponding author, [Galon, L.], upon reasonable request.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.

Additional information

Funding

The author thanks the National Council for Scientific and Technological Development (CNPq) – Grants n. [307291/2016, 406221/2016 and 306927/2019] and for financial support and Foundation for Research of the State of Rio Grande do Sul (FAPERGS)-Grants n.: [19/2551-0000874-0 and 842-25.51/13-4] and for fellowships.