Sand topdressing applied to annual bluegrass [Poa annua L. f. reptans (Hausskn.) T. Koyama] putting greens during the spring and summer can reduce anthracnose caused by Colletotrichum cereale Manns sensu lato Crouch, Clarke, and Hillman. However, the effects of autumn topdressing on this disease and the annual quantity of sand required to suppress anthracnose are not known. A 3-yr field study was initiated in 2010 to evaluate a 3 × 3 × 3 factorial of autumn, spring, and summer topdressing on anthracnose severity of annual bluegrass maintained at 2.8 mm. Autumn and spring topdressing was applied at 0, 1.2, or 2.4 L m–2 yr–1 and 0, 0.6, or 1.2 L m–2 yr–1 of sand was applied during summer. Linear and Cate-Nelson models were used to evaluate the response of anthracnose to annual topdressing quantity. Spring topdressing caused the greatest reduction in disease. Autumn topdressing reduced disease early each year following application, while spring topdressing provided consistent disease suppression throughout the growing season. Summer topdressing rates, similar to those applied on golf courses, reduced disease only in 2012 (mid-to late summer). Additionally, modeling the disease response against annual topdressing quantity indicated that increasing topdressing up to 6.0 L m–2 yr–1 produced a linear reduction of anthracnose on annual bluegrass. Golf turf managers should recognize that autumn topdressing will aid in anthracnose suppression; however, spring applications are more effective when anthracnose is the management objective.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science