Apr 7, 2021

Prowl H2O registered for celery, cuts annual grasses and certain broadleaf weeds

The EPA has approved a new supplemental label for the use of Prowl H2O in celery. The supplemental label expires Nov. 25, 2022.

Prowl H2O may be applied to celery grown on muck soil at one or more days after transplanting. Before applying Prowl H2O to transplanted celery, roots of plants must be established and plants must have regained full turgidity. Prowl H2O may be applied in sequential applications by at least 21 days. The application rate is 4 pints per acre (1.9 pounds active pendimethalin). Up to two applications may be made with a maximum of 8 pints per acre per year. There is 60-days pre-harvest interval for Prowl H2O on celery.

Prowl H2O is a very effective pre-emergence herbicide and provides control of most annual grasses and certain broadleaf weeds. It provides poor control of weeds in the mustard and aster families. Mustard weeds include yellow rocket, shepherdspurse, Virginia pepperweed and wild radish. Aster weeds are common ragweed, common groundsel, dandelion, horseweed, mayweed, pineappleweed, sowthistle and burdock. Prowl H2O is also weak against ladysthumb. It provides good control of pigweed species, common purslane and common lambsquarters. It does not have postemergence activity.

Satellite HydroCap has the same active ingredient (pendimethalin) as Prowl H2O. It does not have a supplemental label to use in celery at present, but the label is expected to come soon.

As of April 4, 2021, the label has not been posted to CDMS and Michigan Department of Agriculture and Rural Development. The printed labels should be available from dealers.

– Sushila Chaudhari, Michigan State University, Department of Horticulture 

Celery field in Benzie County, Michigan. Photo: Bernard Zandstra/MSU Horticulture