Vol. 16—1962 - NorthEastern Weed Science Society

The area was not irr~•• · Within 24C'ltobl's after the
application of the first and second post-emergence treatments,
there were .70 laches and :1t,l::rlnches of. precip:Ltation, respe~
tively. No precipitation ,ococ.rred withio' days after the
third post-emergence application.
~ j l ;J
525
Periodic obs.rvations" for turf injury and crabgrass con-:'::·
trol were made following application of the chemicals. Dis- .'::; .
coloration readinss were taken 5 days after each p08t-emerg ... ~~
application. ' The>percentq •• of crabgrass contrl:)l and turf ..r.~li',
grass injury weredeterminid by averaging Httutes of three '.::'L"
independent observers. : :.\,
~;_ {:I':« ',
The herbicidal materials used and rate of active ingre- :h
dients per acre are included with the data in tables land '2.,'1
Results
and Discussion
Table.laa.d 2 show the ..esults obtaldta With the chemi';"~C'
cals used in this experimeltt~·, ;,m~' :
None. of t\\ .• pre-emergent. chemicals produfed any obserY~:.~·
able turf discOloration ort","f injury.Zytron liquid formulations
were the only trea~dts producirta excellent control
of crabgra .. dUring the entire growing season. Granular zytron
and,dacthal W-50 gave goodeontrol.'
'1::1:
Tricalcium arsenate and calcium propyl arsonate produceef: 1
excellent control early in the season. By mid-summer, contr