Application of Prodiamine to Immature Turfs

Abstract

Turf managers use prodiamine to control annual grasses in mature turfs. Earlier, evaluations of prodiamine have indicated it has an elevated soil persistence and high activity on susceptible species. This persistence raises concern for prodiamine's effect on juvenile turf. An experiment was established to evaluate the effect of prodiamine on juvenile Kentucky bluegrass turf. Significant loss of quality occurred on turf less than one year old receiving a single application of prodiamine at ≥ 1.4 kg/ha. Split applications of prodiamine did not significantly decrease turf quality. Prodiamine at 0.8 and 2.2 kg ai/ha and DCPA at 23.5 kg ai/ha, applied in the fall the previous three years, significantly reduced the number of overseeded Kentucky bluegrass seedlings two years after planting. In a subsequent study, prodiamine at ≥ 0.8 kg/ha and DCPA at 23.5 kg/ha applied once the previous fall significantly reduced the number of overseeded Kentucky bluegrass dlings 56 d after planting. An analysis of prodiamine rate versus seedling density was found to be significantly correlated (r2 = 0.79).