Abstract

Proxy is a newly-labeled plant growth regulator (PGR) for use on golf course and commercial turfgrass areas. Four rates of Proxy (ethephon), 2.3, 3.6, 4.6, and 9.1 kg ai/ha (2.0, 3.2, 4.1, and 8.2 lb ai/A,) were compared to Primo (trinexapac-ethyl) at 1.0 kg ai/ha (0.9 lb ai/A) and an untreated control for clipping reduction and effects on aesthetics of creeping bentgrass maintained as fairway turf. Treatments were applied three times at 28-day intervals during 1998 at locations in Indiana and Wisconsin. Proxy was as effective at reducing clipping yields as Primo, although the magnitude of effects varied between the two locations. In general, Proxy was more likely to reduce turf quality and color than Primo. All rates of Proxy reduced clipping weights similarly, but low rates were less likely to reduce color or quality ratings. Turf density was not affected by Proxy or Primo. Effects of Proxy on creeping bentgrass occurred within two weeks after application and generally dissipated within four weeks, whereas Primo effects occurred within one week after application and generally dissipated within three weeks. Turf quality was occasionally reduced following application of Proxy.