A December ethephon application improves seedhead suppression

Annual bluegrass seedheads negatively impact golf course putting greens: they are aesthetically displeasing, increase disease, and reduce the trueness of the surface. Turfgrass managers often apply ethephon twice in the spring to suppress these seedheads. But recent research discovered that a winter (January or February) application of ethephon, followed by two more spring applications, improves suppression when compared with spring-only applications in Virginia.

A recent study in Crop, Forage & Turfgrass Management sought to validate the findings of a study by Dr. Shawn Askew that was completed in New Jersey and Ohio. The study evaluated seedhead suppression following a single ethephon application in December (when superintendents apply snow mold fungicides), followed by spring applications. The study also determined whether tank-mixing mineral oil (Civitas) with ethephon improves suppression.

The results corroborated the findings of Dr. Askew and further support winter application of ethephon as part of a comprehensive seedhead suppression program. Greater seedhead suppression was observed at all application timings when ethephon was tank-mixed with mineral oil compared with ethephon alone. Further investigation is recommended into the effects of spray surfactants on ethephon activity.

Turfgrass managers currently applying sequential applications of ethephon in the spring to suppress annual bluegrass seedheads should consider incorporating a winter application into their program to improve overall seedhead suppression.