Optimization of the protection system of bulb onion against main harmful organisms in the south of Ukraine

Abstract

To control the development of onion fly and other soil-dwelling phytophages during sowing, the soil insecticide Force 1.5 G (tefluthrin, 15.0 g/kg) should be applied at a rate of 10.0 kg/ha. To control thrips and onion hoverfly during the growing season, when their populations exceed economic threshold levels, the insecticide Connect® 112.5 SC (imidacloprid 100.0 g/L + beta-cyfluthrin 12.5 g/L) should be used at a rate of 0.5 L/ha. In case of repeated mass pest occurrence, the product may be applied twice during the growing season. For the prevention of downy mildew and other diseases, and at the appearance of first symptoms, the contact fungicide Antracol® 70 WG (propineb 700.0 g/kg) should be applied at a rate of 2.0 kg/ha. If necessary, the product may be used twice with a 7–10-day interval. To control downy mildew and other fungal pathogens during vegetation (BBCH 20–29), the fungicide Shirlan 500 SC (fluazinam 500.0 g/L) may be applied at a rate of 0.8 L/ha. For effective control of downy mildew, neck rot, and rust, crops should be treated with the systemic fungicide RIDOMIL® GOLD R 162 WG (metalaxyl-M 20.0 g/L + copper oxychloride 142.0 g/L) at a rate of 5.0 kg/ha, applied twice. To protect crops from broadleaf weeds, at the BBCH 12–14 stage it is necessary to apply the systemic herbicide Challenge® (aclonifen 600.0 g/L) at a rate of 0.5 L/ha. To control grass weeds in onion agrocenoses, the herbicide Agil EC (propaquizafop 100.0 g/L) should be applied at the BBCH 14–16 stage at a rate of 0.8 L/ha. If new flushes of broadleaf weeds appear, repeated application of Challenge® (aclonifen 600.0 g/L) at a rate of 0.5 L/ha is possible.