Vol. 16—1962 - NorthEastern Weed Science Society

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1961 PREEMERGENOE ORABGRASS RESULTS
J. M. Duich,B.R.Fleming, A.E.;Dudeck, G. J; ~op and J. Boydl
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The object of this study ~, .to determine ~etfect of various
commercial and eJq:leX'~ntal preemer$en~el crabgrass c~cals under practica:lconditions
in southeastern Pennaylvard!l where crabgraap is a paramount problem
and permanent turf difficult to"produce. . .
Materialp!w!
Methods
The test was conducted ~t. ~ Springhaven C~ (golf) in Wallingford,
Pennsylvania on two. areas.'l'et!t area No.1 was'#Ie practice fairway
(irrigated) with a history of heaVyc:t'Apgrass infels~~On, annually, and a .:
large popula tion of Poa anmia which predOlllinated spring and fall and usually
faded during the sumiii6rperIod. B+1,l,e~ass, bent and t.,scue accounted for less
than 20 percent of the pemanent turf population. ..
Test area ijo. 2 (non-ir:rig~~) was located~ a fairway satllrated
with seepage water frOlllunderground' springs, primar~y".in the spring and faJJ...
Turf was predaninantJ.;r oreeping ben.~~ !2! trivialie, a~ traces of bluegrass.
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Single applicat1onsof ~~c:m._treatment were~on April 3, 1961
two weeks prior to earliest anticipated crabgrass germination for the area.
The region was characterized by unu~ cold, wet ~th~ which delayed
the initial gemins tion of crabgra!'li' ~or four weeks ph :Area 1 and six weeks
on Area 2. Poa annua growth was also unusually heavYdne to protection from
heavy winterenows and-moist oandi~ for most of i~ growing season. Poa
annua faded ctuickly starting in mid-Jv.],y, A further ~cation of climatlC
conditions was the fir$tmOW1ng date or April 27, wb1~ is late for the area.
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Indivic1ualplQts were 6.x,~ ,.feet with thrll$,repl1cations on Area ~'
and two repli6at10na on Area 2 w1~,j;Q~ controls per ~~lication. Liquid '.'
materials were applied with an experirii'8ntal boom sprayer at 35 psi and 90 gpa.
Dry materials .were diluted with tOUI'QUSrta ot soil a~applied by hand.
There was over 0%18inch of ra:lJi.1'allo"'r a three da;v.~Od beginning the daY
following application. " ".J .
Plots were rated period1o~ throughout the .season for discoloration
and injury. Final orabgrass co~, detemination WBS made on October 2 on
the basis of estimated percent oov~~ ~ce partial co~l often resulted in
more vigorous crabgrass growth due ,to lack of turf c~:tition.
1 Assistant Professor, Instructor, G%'llduateAssistanf/ GI'aduate Assistant,
AgronomyDepar1lnent, Pennsylvania State University and Superintendent,
Springhaven ClUb, respectively.