Response of Creeping Bentgrass in the Desert to Seasonal Applications of Methiozoline for Poa Annua Control.

Methiozoline was applied to creeping bentgrass golf course turf as fall, spring, and fall followed by spring applications, in order to assess seasonal timing response for Poa annua control/suppression. Four applications were made 10-14 days apart at the rate of 0.51 lbs./M and watered in immediately after application.  Poa reductions did not occur until after the fourth and final applications were made.  Annual  bluegrass  control was 95% or greater when applied at both high and low elevation locations. Annual bluegrass did return at the low elevation site (Tucson), resulting in 75-80% control.  Some thinning (loss of apparent density) occurred in the spring at the high elevation location from fall applied methiozoline.  In a previous study, spring applications only, produced control in the range of 65-70% on low elevation bentgrass greens.