Efficacy of chemical products for control of brown rot of peach in north Georgia, 2010.

摘要

Fungicides were evaluated for control of brown rot in an experimental block of a late-ripening peach variety (O'Henry) located at the University of Georgia Horticulture Farm (Watkinsville, GA). Chemicals were applied with an airblast sprayer (60 gal/Aspray volume) on 3 Aug and 8 Aug (pre-harvest sprays). Treatments included an untreated control, Pristine (boscalid + pyraclostrobin) and Abound (azoxystrobin) as chemical standards, DPX-LEM17 (pentathiopyrad) at two rates + surfactant, and two experimental materials (YT669 and Q8Y78) + surfactant. 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 ratings. Unsprayed rowswere 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 for 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, 35 asymptomatic fruit were harvested from each plot for rot assessments (16 Aug). The fruit were placed on plastic produce trays and stored at ambient room temperatures (air-conditioned room; ~77 F). Rot incidence was recorded at four and seven days after harvest.