Submitted to: Pecan Grower
Publication Type: Trade Journal
Publication Acceptance Date: 6/20/2013
Publication Date: 8/1/2013
Citation: Bock, C.H., Cottrell, T.E., Hotchkiss, M.W., Wood, B.W. 2013. Distribution of scab and management of the disease in large pecan trees. Pecan Grower. 25:22-34.
Technical Abstract: Many factors affect spray coverage in pecan trees. Information on the spray distribution and resulting disease severities throughout the canopy can help growers in making choices on the best management options under specific weather conditions in particular orchards. This article focuses on efficacy of ground-based sprays for controlling scab in orchards of tall trees. In experiments there were significant effects of fungicide treatments lower in the canopy on fruit in August, but rarely any difference at the sample sites higher in the canopy in both August and October samples. At heights >10 m control was not consistent and most often non-significant. The lack of scab control in the upper canopy suggests the need for aerial spray applications or alternative tree management such as hedging to reduce tree height to ensure fungicide reaches the upper parts of the tree.