OPTIMIZATION OF THE COMBINED USE OF HERBICIDES AND BIOSTIMULANTS IN CORN

Abstract

The issue of optimizing the combination of herbicides and biostimulants in agriculture is highly relevant due to the need to increase corn yield while minimizing stress factors and conserving resources. The introduction of biostimulants into crop nutrition systems aims not only to boost yield but also to enhance plant stress resistance, reduce the negative impact of herbicides, and improve product quality. However, the combined application of these products can have both positive and negative consequences, necessitating detailed research. The objective of this study is to determine the characteristics of the joint application of herbicides and seaweed-based biostimulants and to assess their impact on corn yield under the conditions of the Forest-Steppe of Ukraine. To achieve this, a series of field experiments were conducted using different combinations of herbicides and biostimulants to evaluate their effectiveness and feasibility. The research was carried out between 2022 and 2024 at the enterprise LLC “Agro-Slava 2017” in the Khmelnytskyi region, Kamianets-Podilskyi district. This article examines the peculiarities of the combined use of herbicides and biostimulants in corn, analyzing their interactions and impact on grain yield and quality. The study established that the effectiveness of herbicide and biostimulant combinations depends on the composition of the products and their influence on plant physiological processes. The highest yield was achieved with the application of a herbicide combination of rimsulfuron + 2.4-D + florasulam, which effectively controlled weeds, particularly broadleaf species. The addition of biostimulants to herbicides produced mixed results: in some cases, they improved crop structure, while in others, they intensified herbicidal stress. Seaweed-based biostimulants influenced the formation of the number of ears per plant, especially Biostimulant 2, which contains a rich complex of phytohormones. However, additional ears often remained underdeveloped, which did not always lead to increased yields. Meanwhile, Biostimulant 1 positively affected structural yield elements, such as the number of kernel rows. In contrast, combinations of herbicides with Biostimulant 2, although promoting active plant growth, reduced the qualitative yield indicators. It was found that the combination of 2.4-D-based herbicides with biostimulants containing natural auxins could trigger a synergistic phytotoxic effect. In some cases, yield reduction was observed due to hormonal imbalances and intensified herbicidal stress. The obtained results highlight the need for further research on the interaction between herbicides and biostimulants, particularly in the context of increasing plant resistance to stress factors and improving yield quality characteristics. The implementation of rational application schemes for these products can ensure effective weed control while minimizing adverse effects on the crop.