Dicamba drift on green onions and possibility for overcoming the herbicidal stress by subsequent plant biostimulant application

M. Yanev, N. Shopova, N. Neshev
Onion (Allium cepa L.) is a widespread vegetable crop with a high content on nutritional substances. One of the most commonly used weed control methods in crops is the herbicidal application. In certain cases, they can have a toxic effect on the crop. Herbicide phytotoxicity can occur as a consequence of herbicide drift on non-target plants or areas. This undesirable phenomenon can be observed in low-volume spraying with small droplet sizes, as well as in conditions of inappropriate wind speed and direction. The aim of the present study was to investigate the effect of different rates of dicamba-containing herbicide product on green onions and its potential to overcome the herbicidal stress by medicative biostimulant treatment. In this regard, in 2022 and 2023, a trial with the green onion cultivar ‘Lyaskovski 90’ was carried out at the Agricultural University of Plovdiv, Bulgaria. The trial was performed with a herbicide drift of Dikash 48 SL (containing 480 g L‑1 dicamba) in rates of 0.10, 0.20, 0.30, 0.40, 0.50, and 0.60 L ha‑1 in crop growth stage 6-8 leaves to be imitated. A comparison of the performance of the plants received different rates of the herbicide and the same rates followed by ameliorative biostimulant treatment was studied. The subsequent treatment with the biostimulant Amino Expert Balans in a rate of 1.00 L ha‑1 three days after the imitation of the herbicide drift was done. The obtained results were compared with untreated control (without herbicidal drift or biostimulant treatment). The onion injury after herbicide application was evaluated, as well as the enhancement effect of the biostimulant. All studied Dicash 48 SL rates caused crop injury resulting in chlorosis and leaf twisting. The damage levels increased with increasing the herbicidal rate sprayed, but enhancement of the plants when the biostimulant for medicative treatment was distributed.
Yanev, M., Shopova, N. and Neshev, N. (2025). Dicamba drift on green onions and possibility for overcoming the herbicidal stress by subsequent plant biostimulant application. Acta Hortic. 1416, 393-400
DOI: 10.17660/ActaHortic.2025.1416.52
https://doi.org/10.17660/ActaHortic.2025.1416.52
green onions, herbicide injury, biostimulant
English

Acta Horticulturae