Integrating cultivar resistance and disease warning system to control downy mildew of onion

Abstract

The management of downy mildew of onion requires frequent applications of protective and systemic fungicides. In order to reduce production costs, we evaluated a control strategy that integrated the use of resistant experimental cultivar and a disease warning system. Regardless of the type of management adopted, the experimental cultivar was always more productive. In turn, management based on the applications of protective fungicide was more effective. Considering only the value of the fungicide and using the resistant experimental cultivar, we had a cost of BRL 3.5 cents/kg for management only with Antracol®; BRL 10.7 cents/kg for management based on the warning system; and BRL 14.8 cents/kg for management only with Ridomil® Gold MZ. The integration of different control strategies for downy mildew can bring greater productivity and profitability to farmers.