Alternative products for controlling Sclerotinia sclerotiorum in vivo AND in vitro in canola crops

Abstract

Products that activate plant defense mechanisms, such as white mold, may increase the disease control spectrum in canola crops as an alternative to chemical control for disease management, aiming at lower environmental impacts and selection pressure on pathogens. This study evaluated Sclerotinia sclerotiorum control and resistance induction in canola crops with alternative products. In vitro and detached leaf experiments were conducted in a laboratory, and in vivo experiments occurred in a greenhouse. High Roots®; V6®; Maxi Flor®; Wert Plus®; potassium, manganese, and copper phosphites; manganese; procymidone fungicide; and Ascophyllum nodosum, Bacillus subtilis, and Bacillus thuringiensis extracts assessed S. sclerotiorum mycelial growth in vitro in detached leaves, white mold severity in a greenhouse, and enzymatic analysis in leaf tissues. The last two experiments also received the acibenzolar-S-methyl and Trichoderma asperellum treatments.  S. sclerotiorum mycelial growth showed 100% inhibition under B. subtilis and Wert Plus® at 1000 ppm and procymidone at 100 and 1000 ppm in vitro. The procymidone and B. subtilis treatments in detached leaves inhibited 100% of fungus growth. The greenhouse experiments with lower severity were procymidone, copper phosphite, B. thuringiensis, B. subtilis, manganese phosphite, potassium phosphite, High Roots®, and V6®. Higher peroxidase enzyme activity occurred in plants treated with acibenzolar-S-methyl, copper phosphite, and fungicide 48 hours after pathogen inoculation. The polyphenol oxidase enzyme did not show activity. Alternative products were responsive and may aid the chemical control of white mold in canola crops.