Bitter rot, caused by a Colletotrichum spp. complex, is a significant disease of apples in the southeastern United States. Symptoms include target-like spots on fruit that render the fruit unmarketable. This report assesses the effectiveness of two fungicides for managing bitter rot. The trial was conducted in 2025 in Blairsville, GA, on a 24-year-old block of Malus × domestica ‘Royal Empire’. Treatments included an untreated control, a standard fungicide spray regimen, Axios, and Bacix. The standard regimen performed as expected, providing substantial control of bitter rot compared with the untreated control. Axios, while showing some efficacy, did not achieve control comparable to that of the chemical standard regimen. Bacix showed no efficacy against bitter rot in this trial.
Melton et al. (Mon,) studied this question.