The Occurrence of Fungal Diseases in Maize in Organic Farming Versus an Integrated Management System

Abstract

Organic farming is becoming increasingly popular because it leads to healthier products. Due to limitations on the use of chemical protection, however, plants may be more susceptible to pathogen attacks. Therefore, the aim of the study was to determine the occurrence of fungal diseases in maize grown in organic versus integrated systems. The field experiment was conducted during the years 2017–2019 in Puławy, Poland. Three maize varieties, Ambrosini, Smolitop and Ricardinio, were cultivated in two fields with a different crop production system. The incidence of fungal diseases, such as northern corn leaf blight, eyespot, common corn rust, corn smut and Fusarium ear rot, was assessed. Fungal isolates were collected from leaves and cobs with disease symptoms and identified microscopically and molecularly. In both cultivation systems, northern corn leaf blight and eyespot were the most common, while corn rust and fusariosis were seen more often in organic cultivation. Alternaria alternata, Fusarium oxysporum, Fusarium poae, Fusarium graminearum and Fusarium sporotrichioides were the fungal species most frequently detected in the two systems. Additionally, Fusarium verticillioides was common in the organic system. Weather conditions, especially heavy rainfall and high air humidity, greatly influenced the incidence of such diseases.