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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #321458

Research Project: Mitigating Alternate Bearing of Pecan

Location: Fruit and Tree Nut Research

Title: Efficacy of Prophyt and Captan as a tank mix when combined for control of peach scab in Georgia, 2014

Author
item Brannen, Phillip - University Of Georgia
item Bock, Clive
item Hotchkiss, Michael - Mike

Submitted to: Plant Disease Management Reports
Publication Type: Other
Publication Acceptance Date: 6/1/2015
Publication Date: 8/1/2015
Citation: Brannen, P.M., Bock, C.H., Hotchkiss, M.W. 2015. Efficacy of Prophyt and Captan as a tank mix when combined for control of peach scab in Georgia, 2014. Plant Disease Management Reports. 9:STF009.

Interpretive Summary: Fungicides were evaluated for control of scab in an experimental peach block (‘O’Henry’) located in Byron, GA. Chemical formulations were applied at petal fall and shuck split with two subsequent cover sprays. Treatment regimens included: Prophyt, Captan 4L, Captan 4L + Prophyt, and Bravo Weather Stik. At full maturity, 40 fruit were harvested from each plot and assessed for scab. Scab incidence (percent infected fruit) and severity (lesions per fruit) were recorded. Scab infections and subsequent symptoms can develop throughout the season, but a critical peak in spore production occurs during the period between petal fall and shuck split. Early-season (petal fall and shuck split) sprays require fungicides with greater efficacy than the standard sulfur cover sprays which are utilized for the remainder of the season. Bravo Weather Stik effectively reduced scab incidence, but there were no significant differences in scab incidence between all other treatments and the non-treated control. Prophyt and Captan tank mixes did not prove to be efficacious, as compared to solo applications of either product.

Technical Abstract: Fungicides were evaluated for control of scab in an experimental peach block (‘O’Henry’) located at the USDA Research Station in Byron, GA. Chemical formulations were applied with an airblast sprayer (100 gal/A spray volume) on 31 March (petal fall to 1% shuck split), 9 Apr (shuck split to 10% shuck off) and two subsequent cover sprays on 23 April and 6 May. Treatment regimens included: Prophyt, Captan 4L, Captan 4L + Prophyt, and Bravo Weather Stik. Five replications of each treatment were assigned to a randomized complete block design, with each plot consisting of four trees. All cultural practices were in keeping with production methods commonly observed throughout the Southeast. At full maturity, 40 fruit were harvested from each plot and assessed for scab (16 Jul). Scab incidence (percent infected fruit) and severity (lesions per fruit) were recorded. Scab infections and subsequent symptoms can develop throughout the season, but a critical peak in spore production occurs during the period between petal fall and shuck split. Early-season (petal fall and shuck split) sprays require fungicides with greater efficacy than the standard sulfur cover sprays which are utilized for the remainder of the season. Bravo Weather Stik effectively reduced scab incidence, but there were no significant differences in scab incidence between all other treatments and the non-treated control. Prophyt and Captan tank mixes did not prove to be efficacious, as compared to solo applications of either product.