Vol. 51—1997 - NorthEastern Weed Science Society

51
TIIE E...·rL"",,- L OF TRINEXAP AC-ETHYL ON PUTIlNG GREEN SPEED
ThomasL. Watschkcand JeffreyA. Borger'
ABSTRACT
This s dy was conductedat TheValentineTurfgrassResearchCenter,University
Park, PA, on mature mixed stand of Penncrosscreepingbentgrass(Acrostis palustris)
and annual bi
grass~ aunual.
Two a plicationsof trinexapac-erhyl(lEe) at tworates,0.06and0.125 07JM,were
applied at two plication timingsto 3'x2Q' plots in a randomized completeblock design.
A hand held C 1 poweredboomsprayer,was calibratedto deliver40 gpaat 30 psi using
two 6504 flat nozzles. The first applicationwas on May30, 1996,thesecondon July
8,1996.
Data c llectionwasinitiated on July 2, 1996,and wascompletedon July 25, 1996.
The test site mowed,in onedirectionperpendicularto the roll of the ball at 5132"on
Monday,Wyand friday usinga triplexreel mowercollectingtheclippings. On
Tuesdays and ursdays after the dew waswhippedfrom the test site, (no mowing)stimp
meterreadingswere takenevery twohoursusing tlll'ee golfballs rolledin two directions
(awayfrom back to a startingpoint) startingat 6 a.m. andcontinueduntil 8 p.m. At
the onset of h two hour datacollectioninterval, a visual weatherobservationandsoil
temperaturew recorded (on some daysinclement weatherprohibitedthe completionof
the full day' 5 ta collection). The test area did not receiveanyfertilizer,andirrigationwas
appliedon an neededbasis,on non data collectiondays. In general,the lowestgreen
speedwasfo early in theday (6 a.m.)andIarerin theday(4 p.m.). Although,on two
occasions,a dday low was recorded Wind, proximityof rainfall to measurementtime,
overall growin conditions(air and soil temperature),leaf'wetness, and other
environmental arametersinteractto impactresults. Onlya slightrate effectwasfound.
At most ob .ontimes, tIinexapac-ethyltreatedturf allowedfor slightlyfasterball roll
(3 to 7 inches),although,on occasion,untreatedturfallowedtheball to roll further. Little
evidencewast; ODdat the rates used,thatrrinexapac-ethyltreated turfcouldprovidea
putting surfacewhich wouldbe of uniformspeedthroughoutthe daythan non treated tuIf.
t Professor and earch Assistant. respectively, Department of Agronomy, Penn State University.
University Park. A 16802