Core Cultivation and Efficacy of Benomyl Applied to Creeping Bentgrass

Abstract

AbstractHollow tine core cultivation is practiced for the management of creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.) Farw.; syn. A. palustris Huds.] golf course greens and fairways to increase water infiltration, increase turf root and shoot growth, and control thatch. Benomyl [methyl 1‐butylcarbamoyl)‐2‐benzimidazole carbamate] is commonly used on turf as a soil drench for the control of disease such as dollar spot (caused by Sclerotinia homoeocarpa F.T. Bennett). Our objective was to determine the effect of core cultivation on the movement of a systemic pesticide in thatch and soil and the uptake by turfgrass using benomyl as a model. Core cultivation was conducted 1, 7, and 14 d before benomyl application in a field trial during 1992 and 1993 to study the effect of coring and time of coring on the movement and uptake of benomyl and control of dollar spot disease. Fungicide levels in turfgrass clippings, thatch and soil were determined by bioassay. Core cultivation 1 d before benomyl treatment provided the longest lasting uptake of benomyl and control of dollar spot disease compared with 7 and 14 d before benomyl treatment. Clipping, thatch, and soil samples from areas close to the coring holes had significantly higher (P = 0.05) levels of fungicide residues than those farther from the coring holes. This study suggests that core cultivation shortly before benomyl application can increase movement of benomyl into thatch and soil, thereby increasing uptake of benomyl by turfgrass and improving disease control.