Vol. 54—2000 - NorthEastern Weed Science Society

SMoorn CRABORASS CONTROL IN 1999
T. L. Watschke and1. A. Borger!
ABSTRACT
Four studies were conducted on a mature standofperennia1 ryegrass at the Landscape
Management Research Center, Penn State University, University Park, PA. One of the studies
was an evaluationof productsforpreemergencecontrolof smoothcrabgrass,one study was an
evaluationforpre-postcontrol. and two studieswere conductedforpostcontrolof crabgrassin
the two to threetiller stage. In the preemergence stndy, a randomized complete block design was
used with threereplications. All of the treatments were applied on April 28, 1999 using a three
foot CO, powered boom sprayer calibrated to deliver 80 gps using two, flat fan, 6504 nozzles at
40 psi. Granulartreatmentswereappliedwitha shakerjar.Afterapplicationthe entiretest site
received approximately0.5 inch afwater. Crabgrassgerminationwas firstnoted in the test site
on May 12, 1999. Non treatedchecks were ratedto have a minimumof80 percentcrabgrass
infestationin all replications.The pre-poststudy,wasa randomizedcomplete block design with
threereplications. All of the treatments were applied on June 18, 1999 using a three foot CO,
powered boom sprayer calibrated to deliver 40 gpsusing two, flat fan, 6504 nozzles at 40 psi.
Granulartreatmentswere appliedwitha shakerjar.The post emergencestudies were randomized
complete block designs with three replications. All of the treatments were applied on July 19,
1999 using a threefoot CO, powered boom sprayer calibrated to deliver 40 gpa using two, flat
fan,6504 nozzles at40 psi. In the preemergencestudy,most of the herbicidesused provided
commercially acceptable control (at least 85%). Those providing the best control (at least 95%)
werethe following; prodiamine 65WDO at 0.5 and 0.651bs ailA, dithiopyr IEC at 0.38,
dithiopyr 40WP at 0.25 and 0.381bs ai/A, dithiopyr FO AND445 0.1640 at 0.381bs ailA, and
XF99007 2.32SC at 0.25 and 0.381bs ai/A. Those providing from 90 to 95% control included;
prodiamine 65WDG at 0.381bs ailA, AND672-99 at 3.61bs productIM, XF99006 2.32SC at 0.25
and 0.381bs ailA, pendimetha1in 60WO at I.5lbs ailA, Team Pro, 0.860 at 21bs ailA, and
dithiopyr FO AND445 0.1640. Those materials that did not provide acceptable control were;
01 1399B, 011399C, 012799E, 012799F, prodiamine at 0.251bs ailA, AND669-99 at 3.61bs
productlM, AND670-99 at 3.6 lbs productlM, dithiopyr (Crabex) 0.140 at 0.125 Ibs ailA,
pendimethalin (Scotts) 0.860 at 1.5 lbs ailA, oxadiazon 20 at 2.0 lbs ailA, and Team 0.870 at
2.0 lbs ailA. In the pre-post study, acceptsble postemergence control of smooth crabgrass was
atrained by applications of the following herbicides; Drive 75DF at 0.75 lbs ailA with I%v/v
MSO, Drive 75DF at 0.75 lbs ailA plus 0.375 lbs ai/A of Dimension and MSO at 1% vlv, Drive
75DF at 0.751bs ailA plus I.5lbs ailA ofpendimethlin andMSO at I%v/v, and Acclaim Extra
0.57EWat 0.091bs ailA plus Dimension 40WP at 0.51bs ailA. All treatments containing
granular Drive, Proclaim 3.09EC at 2.061bs ailA, Dimension40WP at 0.5 and 0.251bs ailA and
Puma I EC at 0.12 lbs ailA did not provide a commercially acceptable level of control. In the
post emergencestudy,acceptablepostemergencecontrolof smoothcrabgrasswas attainedby the
application of Acclaim Extra 0.57EW at 0.121bs ailA, Puma IEC at 0.121bs ailA, Acclaim Extra
IProfessorandResearchAssistant,respectively,Departmentof Agronomy,Penn State
University, University Park, PA, 16802
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