Issue link: http://read.uberflip.com/i/683571
108 of no net reduction in growth and possibly a net increase. It is also important to consider grass species when thinking about the Primo longevity. Creeping bentgrass and Kentucky bluegrass metabolize Primo at different rates. We are finding this to be true regarding annual bluegrass and creeping bentgrass. Poa annua is metabolizing Primo quicker than the creeping bentgrass. The net effect is Poa enters the rebound phase, while the bentgrass is still in the suppression phase of growth. This may give the Poa a competitive advantage over the desirable creeping bentgrass. To minimize this advantage, Primo needs to be re-applied sooner before the Poa enters the rebound phase. But we are getting ahead of ourselves. Let's start with the basics: How can a growing degree day system Help witH my primo maxx applications? A growing degree day (GDD) system is helpful when using Primo because it predicts Primo's effect on turf growth. The system is very simple to use. After Primo is applied the daily average air temperatures are added together until Primo is re- applied. At that point the model is reset to 0 and the process is repeated. The temperatures are recorded in degrees Celsius with a base temperature of 0°C. The model has been calibrated and validated over the past few summer on several creeping bentgrass putting greens. PUTTING GREEN CARE