Vol. 54—2000 - NorthEastern Weed Science Society

BROADLEAF WEED CONTROL IN 1999
T. L. Watschke and J. A. Borger'
ABSTRACT
This study was conducted on a mature standof perennial ryegrass at the Landscape
Management Researcb Center, Penn State University, University Park, Pa. The objective of the
studywas to determinethe efficacyofbroadleafweed herbicideswhen appliedin earlyandlate
summerforcontrolof dandelion,conunonplantain,andwhite clover.
This study was a randomized complete block design with three replications. All of the
treatments were applied on June 7 and August 31, 1999 using a three foot CO, powered boom
sprayer calibrated to deliver 40 gpa using two, flat fan, 6504 nozzles at 40 psi. Control of the
weeds was rated on August 9 and Oct 6,1999. The treatments were: L-0337, L-0338, Dive,
Drive and Momentum, NB20332, NB3040l, NB30402, NB30403, NB20334, NB30405, Trimec
Classic, Confront, Momentum, Weed-B-Gone, Acclaim Extra and Confront, Preclaim and
Confront.
Applicationsof the commercialstandardsMomentum,TrimecClassic, Confront,and
weed-Bajcoe resultedin very good to excellentcontrolof white clover andcommonplantain
bowever, all of the standards had relatively poor control of dandelion when rated on Aug 9.
Observation of the dandelions 4 to 6-weeks after application revealed apparent good control.
However, by the eight-week rating date, many of the dandelions had resprouted from the taproot.
All of the treatmentshadsome level of controlof commonplantainandwhiteclover, butall had
limited control of dandelion. Of the series, NB20334 appeared to have best range of control
acrossthe threeweed speciesbutstillnot acceptableon dandelion.Theadditionof Acclaim
Extra to Confront did not appear to antagonize efficacy as Acclaim or Preclaim. Drive provided
excellent control of white clover by itself. Combining Drive with Momentum (L0338) improved
common plantain control slightly. Tank mixing Drive and Momentum resulted in improved
dandelioncontrolcomparedto Momentumalone,butthecontrolof white cloverwas decreased.
All treatments were reapplied on Aug 31 and a second rating for control was made on Oct 6. All
treatments provided acceptable dandelion control except NB30405, and the combination of
Preclaim and Confront. All treatments provided acceptable plantain control except L-0337 (Drive
0) Drive. Only NB30405 failed to provide acceptable control of white clover.
I ProfessorandResearchAssistant,respectively,Departmentof Agronomy,Penn State
University, University Park, Pa, 16802
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