Efficacy of fungicides for control of brown rot of peach in northeast Georgia, 2011.

摘要

Fungicides were evaluated for control of brown rot in an experimental block of a late-ripening peach variety located at the University of Georgia Horticulture Farm (Watkinsville, GA). Chemicals were applied with an airblast sprayer (60 gal/A spray volume) on 21 Jul and 28 Jul (pre-harvest sprays), 2 and 1 week before harvest, respectively. Treatments included an untreated control, Pristine (boscalid + pyraclostrobin) and Abound (azoxystrobin) as chemical standards, Fontelis (pentathiopyrad), Luna Sensation (fluopyram + trifloxystrobin), and Merivon (pyraclostrobin + fluxapyroxad) at two rates. Five replications of each treatment were applied to a randomized complete block design, with each plot consisting of four trees; the outer two trees in each plot were not utilized for disease assessments. Unsprayed rows were left between each spray row. All cultural practices were in keeping with peach production methods commonly observed throughout the Southeast. Earlier in the season, maintenance sprays against scab (Bravo WeatherStik 6F at 4 pt/A at shuck split and Yellow Jacket Sulfur 90WP at 9 lb/A through all cover sprays) were applied to all treatments, including the untreated control. At full maturity (4 Aug), 39 asymptomatic fruit were harvested from each plot for rot assessments. The fruit were placed on plastic produce trays and stored at ambient room temperatures (air-conditioned room; ~77 F). Rot incidence was recorded 4, 8, 11 and 16 days after harvest.