Vol. 16—1962 - NorthEastern Weed Science Society

479
'!HEEFFECTOJ1"CERTAINPREEMEqNCE
CHEMICALSONGRASS~ATION ANDSFlElllLINGRASSES
"f),' 1
J. M. Mch, B. R. Flem1Bg, A. E. Dudeck ~ G. J., Shoop
. The objectives of thj,s lJ:twiywere to de~m;ine the effect of
several preemergence chemicals on seedlings of tht'ee major turfgrass
species 'Whenapplied at varying intervals followiq Beeding, and their·
effect on the germ1llation of tbeee: grasses 'WheneNded at varying intervals
following applica tiona :.'}
Mater:Lals ~ Methods
This stud;r was conduo~~ at University~k, Pennsylvania on
HagerstownsUt loam soU with a pH of 6.3 and med:lumlevels of avaUable
phosp.orous and potash. Initiation of the study was delayed until
la te spring due to inclement weather. The area was trea ted with hot
methyl bromide at 1.2 pounds per 100 square feet in late May 1961,
following root zone tillage, to eliminate any undClSired plants during
the growing seaSal. Prior to ~J, seedbed prePQJlltian, 45 1bs. of
10-5-5 (70% ureaform and 30% act;tvated sludge ni~en) per M was
applied.
Turf was maintained at lilt height of clIt, throughout the season
with all clippings removed. Irrigation was a:flllied for establishme~t
and maintenance, however, the turf: was allowed t,,,..mowmoisture stress
prior to maintexumce watering to a:llow any possib:J;, trea1ment effects to
be expressed.
Post-emergence Test. On June 20, 1961 cOnunOnKentucky bluegrass,
creeping red fescue and Astoria bent mre"eded in individual
3 x 63 foot adjacent strips at 2, 4 and 1 pound p~ M, respectively.
Three foot sod strips were placed parallel to eacl;l(series of seeded strips
to facilitate mulch removal, irription, etc. ~:experimental design ""'s
a triple replicated randomized block with trea1m~t dates, grass species,
and chemical trea1ments the respective factors.
Chemical trea1ments lIilI'f awlied in J,x9 foot strips perpendicular
to the grass strips resu1~ in 3 x 3 foot 1a'eatments an each grass
species. Treatments were madeqat 6, 38, 69 and 190 da,ys following seedimg.
Preemergence Test. '1he'above chemicalt.reatments were applied
at similar rates ana piOtSizes toa prepared seedbed on June 26. All plots
were mulched w:1,th,first-cut fo~ge at approximate~ 100 pounds per M to
assimilate a turf cover condition.nd to, preventllflJterial movement and
exposure to light. The three grass species were Meded at 0, 32, 63 and' 93
1 Assistant Professor; Instruotor and Graduata J\.msistants, respectively.
Agrono~ Department, Pennsy1vania State University.