Control of the volunteer plants of imidazolinone sunflower in oil flax sowings

The research was conducted in 20202022 to find effective ways of controlling the volunteer plants of imidazolinone-resistant sunflower in oil flax sowings, providing high biological and economic efficiency, crop yield, and seed quality on leached chernozem in natural and climatic conditions of the Western Ciscaucasia. We studied methods of chemical protection of oil flax with tank mixtures of herbicide combinations: anticotyledonous contact herbicide Basagran, WS and systemic herbicide Cleo, WDG, Sekator Turbo, OD, and graminicide Zellek-super, EC. We used established methods for field agronomic experiments with oil crops. Seeds of imidazolinone-resistant sunflower hybrid were evenly sown on the experimental plot to simulate the volunteer plants. The phytotoxicity of herbicides on sunflower plants was evaluated using a 9-point EWRC scale. The tank mixtures Basagran,WS (4 l/ha) + Zellek-super, EC (1.0 l/ha) and Basagran, WS (4 l/ha) + Sekator Turbo, OD (0.1 l/ha) + Zellek-super, EC (1.0 l/ha) do not provide effective control of the volunteer plants and are not recommended for use. The composition Basagran, WS (4 l/ha) + Cleo, WDG (0.12 kg/ha) + Zellek-super, EC (1.0 l/ha) provides destruction of the volunteer plants, contributing to higher yield and oil content of seeds, but it is very expensive and decreases the laboratory germinating ability of flax seeds, so it cannot be used in industrial seed production. A tank mixture of Cleo, WDG (0.12 kg/ha) + Sekator Turbo, OD (0.1 l/ha) + Zellek-super, EC (1.0 l/ha) has lower cost, provides high herbicidal effectiveness against the volunteer plants of imidazo-linone-resistant sunflower, contributes to obtaining a high yield, oil content and laboratory germination of oil flax seeds and is recommended for use both in industrial seed production and in the production of commercial seeds.