Vol. 16—1962 - NorthEastern Weed Science Society

. ~lS
residual cemtrol of crabgrssi~oiitnnet!''td tfiCi,tl~£wij .f~~riate also can ;'bi.r~tiri_
buted to residual chemical ac.tiJd,ty. Although teste are in progres$, it is not
yet .knownwheth.tF;jgirri'4±d~a+;rettects of zytron .nd~~~cthal on crabgrass the
~~ar, f~~lo~-;.~Wt;~e,~ residual ohelld:o.1·....ctivity"-or- the' prevention
.·or·~~e:¢~~;:1.'n the..leU~atment. t'1;.~es on residU81e~~cte ot
~s-Qlt) 'iJless 1M', .) being ccntAn'Ud. ..'-
f; ') ~ f~'i,; ~,~ :mr \J,~~)'!:
SWlImaryand ConclUsions
itfumpBriso~':Were made of~.veral pre-eJigrg:~~6:berbicide~£6r,~",qg~~~1
of cr,abgrass W.established ~t. To evaluate ..the performan\l8S.,or;'v:ar.~ ,:~
ohetid'cals, efftdts of season 'of application, residual activity, a~ .h~~ ot
out were studied.
.'
Spr;l.ng app~ications of dtihium arsena1;.e,:Cbi~ne, da'c\'hal',' iiPax',j:'!iridi:.i
zyt1'9n 'oontro],ll'd; orabgrassb,tter than fell" a'p'pffo~tions. ,~thoj1g~,~,~plicatiOns
may'be' -Slightly leSS' 'injurious to turf, spring appl~cations appear to
be l1}9re·practj,.,C;Jl. Severalttp.ngs may happen to lawns bct-ween,OCtob~~.~'­
that-' could red-b.icethe effect1"vtlneas of fall appiications,' f.e., rakirig"o~.leaves
and ~ass, flcwliin~, etc.. o :>" .. Tt~Yf '.\. "(sri.,,,,;,'
Raising tti"el:
height er c~t" from 1 to 2 inches sreatly r~~u'ced cra~~~~~:'
..'.,8.1...'.'f.• ,...._al
pop~ationa ~. increased the. ~£fectivenesso,t. ~y!tJ:pn and dac:th
imp]jcation is',that good cr@~asa control may.pEIachieved evep :w~th· ,~~ll1Y
inetfective he-tbicides if the'turt is mowedhigh. It also can be expe d .
that ~ood o~~l of crabg:t!Js, in closelyc~1;. ~'1111t such as~:tt~8,;~'"
wil1)'r~quire high rates of ap~lication or.~8,hlYHM'fective msterials. .:
At normal 'fates of appUhhtion in April or -early May, an"di' th/'l~b~iied
mate~a18 tes~,g except "Pax~~ controlled cr~8i%'~...."atisfactority~1 ,'1'!tql~mentel
materia~!, "Bamane" ~pd dipropalin, als9Provided good ~on~~~-rtO'T .
,qalcium a?i~lffiate
has inj~t'd Golonial bflH:Ii,r."frand fesou~~ljl~~8Ic~ut
in 8,ometests~~~liereas "Pax", s caused little 9r no turf inj\l~.. ,~LM~;.
apol:l.cations m'at be hazsrdouS' th both materials. Calcium propyl arsonate-has
injured fe8cl1e~bluegraas..turt j,n. two...di£fe;,~t-,UNs... ' - - - -..
Even at hi~h rates of application, chlbi'dei'14i'1tajY~~t iri.1\l~d' t~rl i~~.~
test. For COllsistent control of orabgrass, however, rates higher than the
o~r,~~!' ;:s.~g~~t!%;! q~~Z:~~ffl dr,~ ,,~t 6Q.lbs.1 ,A;l~~o~eq.ed. ,- . :,. ';:,,,1'1
. ;.' nrphenlltrfi~~~'; je~ ~~;hete "fiSt f;~h~' .f'iJ'.st.tlmt:)j'.i961~ ..~ i.njur~~~tJ.i.l
..:~,~~~~.~~~~~,:·:t~n,-r J()~.jl/!:':·~" ,.~;~~,~~~~,~,::;', "~' .~"r ...,~.·'l.:-tl;·'·;·· :,~~:.:'jJ .. ""."" \'T~"·) ".1"" .
. .',';.-i"S~gg~~U~c6'.~ci~lj~f~~;' ~adti{Ji sbd"ti~h8';e ilo;ri~ist~n~li p~~vided
.)~.q~=:.r:~r~t,?f: m~t~~·s, '.'~t¥':\\ ~~~101,14t .iw.~,~!p.JIlOst.q1' .t~ qollllllQl1~lp-t
,_j:'~:,~. ~,~, ! A\.e:J.! i"\',~ ;" ·t~tl'n,::, '~,:'.' '> 1 ',.J f lflr'1: J.. .': .. .f:~ "!,:)
- . Resid\i~l; Jdi'itiJ8f\1.tJoraf)~ajJc~I'~e6odd~~a~'ori~tbee~obt~ined with'si~le
'1/.ll..P.,P.l..i.ca~,~..o.ns.,
i'5srlbS"''&;'-aMIi' , itli~ne 'at-\:uP, t.w,""w"'J e..I,A,t1a~I',tWll in ..rl..c .... ~9t . ,JIt1e~ .e. at
r(~h1lf"re.s.i~~.'-;,,'. ~~.J~~.'.