Michigan State University Turfgrass Scienceturf.msu.edu

Proxy/Primo Injury on Bentgrass

Apr 14, 2010 at 10:00am  —  Ronald Calhoun

The net result of some really warm weather following application of Proxy/Primo has resulted in a few reports of turfgrass injury across the region. Three or four days of 80 degree temperatures immediately following application can lead to too much ethylene accumulation in creeping bentgrass (purple discoloration). Bleaching of the leaf tips is associated with Primo (this usually happenes when the plants are growing too slowly to have the tips removed by routine mowing. Both issues are transient, the turf will recover in a week or so. Lastly, plants growing in dry and compacted soils will be more susceptible to wilting injury (bronzing) associated with Primo application. Unsual spring weather conditions may elicit these unusual responses this year.