Why long-term PGR use makes sense

A key aspect of successful and effective plant growth regulator (PGR) performance is consistant use over the long term. The following study examined this notion and found substantial and sustained reducations in annual bluegrass population over a four year period.

The Study

The study took place on a creeping bentgrass fairway in Lexington, Ky., between May 2005 and Spring 2008. Treatments were applied from May to November of each year. In total, eight treatments were made each year on three-week intervals. Throughout the study, annual bluegrass density was evaluated on a nontreated plot, plot treated with Trinexapac-ethyl at 11 fl. oz per acre, Cutless 50W at 8 fl. oz. per acre, and Cutless 50W at 16 fl. oz. per acre. The data
 

 

Conclusions

• A program approach to annual bluegrass conversion can reduce annual bluegrass populations over time.
• Herbicide application alone is not effective for complete annual bluegrass control.
• It's necessary to continuously discourage annual bluegrass growth and development through applications of a plant growth regulator (PGR), such as Cutless, due to the continuous germination and aggressive colonization potential of annual bluegrass.
• Trinexapac-ethyl applications were not evaluated in 2008 because of poor performance in 2006 and 2007.