Suppression of <i>Neonectria ditissima</i> growth on agar by <i>Bacillus</i>-based products

Abstract


 
 
 European canker (Neonectria ditissima), is an important disease on apple trees. Four biological Bacillus-based products and four fungicidal products were tested for efficacy against this pathogen on water agar (WA) and potato dextrose agar (PDA). Neonectria ditissima colonies grown without the biological products were healthy, but when mixed with biological control agents, the colonies were smaller and more diffuse. An interaction between medium and product was observed at 20˚C. BacstarTM, Serenade® Optimum and TripleXTM reduced colony growth on PDA but not on WA, while Fulzyme® Plus reduced colony growth on WA but less on PDA. Interestingly, the efficacy of the products was not improved when 10 times label rates were used, except for Fulzyme Plus on WA. At 10˚C and 15˚C Fulzyme Plus was the most effective biological product, particularly at 10 times label rate. Activation of the biological products (25˚C for 3 h) did not increase their efficacy. CapetecTM (captan) and a mixture of HML32TM + HML SilcoTM prevented pathogen growth. ARMOUR-Zen® and Esteem® did not reduce the number of colonies. More research is needed to determine whether biological products can be used to control European canker.