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Scalping Tall Fescue as Soon as One Day after Treatment Does Not Reduce Glyphosate Efficacy
Author(s) -
Thompson Cole S.,
Hoyle Jared A.,
Braun Ross C.
Publication year - 2019
Publication title -
crop, forage and turfgrass management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.29
H-Index - 10
ISSN - 2374-3832
DOI - 10.2134/cftm2018.12.0098
Subject(s) - glyphosate , day treatment , agronomy , biology , zoology , toxicology , medicine
Core Ideas It is common to scalp glyphosate‐treated areas to sow desirable species following treatment. Product labels recommend withholding mowing for several days before or after an application. Information is needed to precisely define scalping restriction recommendations surrounding glyphosate applications. Scalping tall fescue from one hour before to one hour after glyphosate treatment reduces efficacy. Glyphosate efficacy is not reduced when scalping occurs as soon as one day following treatment.Glyphosate ( N ‐(phosphonomethyl)glycine) is commonly used during renovations and to control difficult weeds. Users commonly scalp treated areas to sow desirable species following treatment, and most product labels recommend withholding mowing for several days before or after treatment. Our objective was to determine the effect of scalping timing on tall fescue [ Schedonorus arundinaceus (Schreb.) Dumort.] control with glyphosate in fall or spring. Three‐inch tall fescue was treated with glyphosate at 2.24 lbs a.e./acre and scalped one day or one hour before treatment, or one hour or one to five days after treatment at two locations (Nebraska and Kansas) in fall and spring. Green cover of tall fescue was rated until 32 or 8 weeks after treatment (WAT) for fall and spring experiments, respectively. In fall, glyphosate efficacy was not reduced when turf was scalped one to five days after treatment (0 to 3% green tall fescue cover by 32 WAT). With the exception of scalping two days after spring treatment with glyphosate in Nebraska, the same was also true in spring at both locations (0 to 8% green tall fescue cover by 8 WAT). Scalping within one hour of glyphosate treatment consistently and significantly reduced efficacy, and scalping one day before treatment only yielded control similar to the best treatments in Kansas in spring. Tall fescue control with glyphosate is not reduced by scalping as soon as one day following treatment in either fall or spring, which is two days sooner than typically recommended.