Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Sequential applications of preemergence and postemergence herbicides for large crabgrass (Digitaria sanguinalis) control in tall fescue (Festuca arundinacea) turf.

Abstract

Pre-emergence (pendimethalin, prodiamine, dithiopyr, oryzalin and oxadiazon) and post-emergence (MSMA and fenoxaprop) herbicides were sequentially applied to Festuca arundinacea turf during 1995-96 in Georgia, USA, to determine the lowest herbicide rates needed for acceptable control of Digitaria sanguinalis. Prodiamine (0.3 and 0.8 kg/ha) resulted in 85 and 96% weed control, respectively. Sequential applications of oxadiazon (1.1 kg/ha) in late February, followed by fenoxaprop (0.2 kg/ha) in June resulted in 85% weed control in late August. Control was similar in mid-August, when pendimethalin (1.1 kg/ha), dithiopyr (0.2 kg/ha) or oryzalin (0.8) was followed by fenoxaprop (0.2 kg/ha), but control was ≤74% by late August. Better weed control was found in combinations with fenoxaprop than in combinations with MSMA (2.2 kg/ha). The turf quality was not affected by prodiamine, dithiopyr and oxadiazon. In 1996, pendimethalin (3.3 kg/ha) and oryzalin (2.2 kg/ha) reduced turf quality by 16 and 46%, respectively. In 1995, MSMA reduced crop quality by ≤21% as compared to fenoxaprop (≤10%). Sequential herbicide programmes did not affect turfgrass quality as compared to single treatments.