Vol. 51â1997 - NorthEastern Weed Science Society
Vol. 51â1997 - NorthEastern Weed Science Society
Vol. 51â1997 - NorthEastern Weed Science Society
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
60<br />
CHEMICAL CONTROL OF YELLOW NUTSEDGE:<br />
EFFECT ON CORN SILAGE YIELD AND WEED BIOMASS<br />
J.M. Jemison,Jr. 1 and MH. Wiedenhoeft 2<br />
ABSTRACT<br />
The ntrol of yellownutsedge(CyperusesculentusL) is becominga problemfor corn<br />
produ rs in the Northeast. Throughnutletsand rhizomes,nutsedgeis easilyspreadto many<br />
fields n tractors and tillageimplements.Whilemanyproducts are registeredfor use on<br />
nut e, their effectivenessvariesdependingon the time of applicationand environmental<br />
condi ons. Ultra-lowrate herbicidesare availablethat maybe environmentallysaferto use<br />
than e more leachableherbicidesused at higherrates. Thesestudieswere designedto assess<br />
the re :tiveeffectivenessof differentproducts andtimesof application.<br />
The p ominantweeds in this studywere yellownutsedge,mustard,and quackgrass. We<br />
ed three control strategies: pre-plantincorporated,preemergence,and post emergence<br />
measures. Each treatment containedproduct combinationsdesignedto controlthose<br />
•es,and all productswere appliedat recommendedrates. Each treatmentwas<br />
with a backpacksprayerat 20 gpa and 30 psi. <strong>Weed</strong>biomasswas sampledat canopy<br />
closur and silagewasharvestedby hand at maturity. For the preplantincorporatedand<br />
preem rgencetreatments,we used metolachlorandatrazine. In the postemergence<br />
treat<br />
halo<br />
ts, we compareddifferentmodes of actionsand timesof application.We compared<br />
ron and nicosulfuronappliedearlyand late postemergence(earliestand latesttimes<br />
ended). We compareda singleapplicationofbentazon with an applicationofLaddok<br />
by bentazonat the recommendedstagesof corn development.Lastly,we also<br />
ed nicosuIfuronwith pyridateas anothertotal postemergenceprogram. We had hand<br />
and untreated controlplots.<br />
, environmentalconditionswere verywet and cool whichinfluencedboth com and<br />
e growth and development. Nutsedgebiomassand relativecontrolare presentedin<br />
. We foundadequatenutsedgecontrolwith metolachIorand atrazinepre-plant<br />
inco rated and appliedpreemergence. ApplyingLaddok earlypostemergencefollowed<br />
with a secondapplicationofbentazon also providedgood nutsedgecontrol. The combination<br />
ofhat sulfuronand nicosuIfuronappliedearlypostemergenceburnedbackthe nutsedge<br />
foliag and controlledother weed speciespresent. Allother combinationsandtimesof<br />
appli :tionwere generallyineffective. Highestcornyieldswere foundwith the preplant<br />
inco rated treatments. Mixingthe herbicidein the biologicallyactivezonein the soilhelped<br />
contr I nutsedge andother weeds early,allowingthe com to get wellestablishedwithless<br />
comp .tion. We found statisticallyequivalentsilageyieldswith alltreatmentswhere nutsedge<br />
contr I wasover 95% comparedto the untreatedchecks. By waitingto applyherbicidesuntil<br />
the was 6 - 8 inchestall,weed competitionwas too great and yieldswere impacted.<br />
Condi ionswere extremelyfavorablefor nutsedgedevelopmentin 1996. Nutsedgewas not<br />
comp elyeliminatedwith the use of anyof these products or timesof application. By<br />
h th r wa vi Ien ed e in all lots.<br />
1 ciateExtensionProfessor- Universityof MaineCooperativeExtension<br />
2 Ass ciateProfessor - Departmentof AppliedEcologyandEnvironmental<strong>Science</strong>s
Change language