OBJECTIVE: To determine whether spring dead spot of bermudagrass can be controlled
or reduced in severity by verticutting, slicing, or stripping in midsummer
PERSONNEL: Ned Tisserat and Jack Fry
INTRODUCTION:
Spring dead spot (SDS), caused by the root-infecting fungus Ophiospharella herpotricha, is a debilitating disease of bermudagrass that reduces turf quality. We evaluated summer vertical mowing, aerification, aerfication plus vertical mowing, and sod stripping for effects on suppressing SDS.
MATERIALS AND METHODS:
Treatments were imposed on Midlawn bermudagrass during the summers of 1993, 1994, and 1995. Treatments included: 1) aerification in two directions (hollow tines 2 inches deep) with a Ryan Greensaire; 2) vertislicing in two directions with a standard vertical mower (blades to penetrate turf about 1 inch deep); 3) aerification and verticutting; 4) stripping the plots; and 5) untreated. Treatments were arranged in a randomized complete block design and were applied in June, 1993 and June and August 1994 and 1995.
RESULTS:
Spring dead spot severity has declined steadily in all treatements since the first year. This indicates that the pathogen is less aggressive and/or the environmental conditions suitable for the disease were optimum in the first year. Stripping (harvesting) sod and allowing regrowth reduced plot damage by 15% in 1994 and eliminated symptoms in 1995. This is not a practical solution to reducing disease severity, but indicates that new bermudagrass arising from in-ground rhizomes does not exhibit SDS symptoms in the first year. Aerification plus vertical mowing reduced plot damage by SDS by 14% and improved turf quality in spring, 1995. Aerification and vertical mowing alone had little effect on SDS symptoms. Intensive aerification and vertical mowing are recommended to suppress SDS.