Field Trial - Seedhead Suppression

Macro-Sorb® Foliar and Embark® T&O for Seedhead Suppression of Poa annua on Putting Greens

Study conducted by Dr. Watschke & Borger, Pennsylvania State University


The production of annual bluegrass (Poa annua L.) seedheads reduces turf quality and effects playability of a putting greens.  Embark® T&O (mefluidide 3.2%) effectively suppresses annual bluegrass seedheads, however, turfgrass injury is a concern when applying at rates that optimize seedhead suppression.  By adding Macro-Sorb® Foliar to applications of Embark® T&O, application rates can be reduced to optimize turf safety, while increasing seedhead suppression. This study was conducted on a mixed stand of creeping bentgrass and annual bluegrass.  All treatments were applied on April 14, prior to the onset of seedheads.  Embark® T&O (40 fl oz/A) applied alone resulted in 87% seedhead suppression, however, unacceptable phytotoxicity was observed following treatment.  Applying a lower rate of Embark® T&O (35 fl oz/A) reduces phytotoxicity, but also reduced seedhead suppression to 78%.  By adding Macro-Sorb® Foliar at 2.0 oz/1000 ft2 to Embark® T&O at 35 fl oz/A, seedhead suppression increased to 92%.  Results from this study indicate that Macro-Sorb® Foliar enhances Embark® T&O for annual bluegrass seedhead suppression.

Figure 1. Seedhead Suppression (%) of Annual bluegrass