Mummy berry management in rabbiteye blueberry with chemical and organic fungicides

摘要

Fungicides were evaluated for control of mummy berry in an experimental block of a mature (>20 yr) rabbiteye blueberry variety ('Tifblue') located near Toccoa, GA. Except for Abound, which was applied as a concentrated drench, all products were foliar-applied with a 3-gal pump sprayer (35 gal/A spray volume). Application dates were 29 Mar (green tip), 9 Apr (10-20% bloom), 15 Apr (full bloom), and 20 Apr (late bloom), although not all treatments were applied on all dates (see table below). Treatmentsincluded an untreated control, Indar (fenbuconazole) as the chemical standard, Regalia (extract of Reynoutria sachalinensis), Quilt Xcel (azoxystrobin + propiconazole), Quash (metconazole), Indar alternated with Optiva (Bacillus subtilis), Indar at green tip and full bloom only, and Abound (azoxystrobin). Five replications of each treatment were applied to a randomized complete block design, with each plot consisting of one bush; unsprayed bushes were left between each spray bush. All cultural practices were in keeping with blueberry production methods commonly observed throughout the Southeast. At the late green berry stage, 100 asymptomatic fruit were harvested from each plot for mummy berry assessments (12 Jun); each fruit was dissected and presence of fungal colonization of locules (+ or -) was recorded.