Vol. 16—1962 - NorthEastern Weed Science Society

18
containing fertiJ.izer were app118dto the t;re8ted.ar~a~ TheappJ.ic.ti~~, ~t
nitrogen st1muliltiecl the foliar growth of thegrasl ..,nd tended to incre.se, the
. number of shoots produced.' Both ()f these :reSpo~se~;lIccelerlited the rate of·
carbohydrate, de,P,l,~ti,on., Th," ,e qU,at;l,k,g~'~8 Plants,,.fe,'Il,PO,,, .,n", ~,",dd to, a pPlic,at10nl!l" Of, '
atraz1ne a8 low as OS lb!A, but the.etfect wastrapfi1;ory, probably becaua.e
of, .a sho.rt period 9£ residue, in'the so11. un~rboAQi7ions favorable f~
growth' an epp%'eei81;lleresidue or ·.trazine W!lS peedecl,Ul. the eo11 for .bout
2 m:lnths in ord~r tel fully dep+et.~, tpecarbohydrat~8..~ thel'hizomes.nq.s
waf!generally accoll1pJj,shedwith ~l?P.J,.ications ot 41,~/J\. of atrazine and OClcasionally
at th.g :l.blA rate .w~!'1' t~agewas \leel! w;retardregrowth aft.~
a period of depletion. " .
,., ,LeBaron an4Fertig(7) aleosl1cl~d that ~trqlz:educed fructose Qc!Ij1­
centrstions in rl1izomes of treats!! plants. Tbe :re4wition was not as drastic
as 'lI'henatrazinewasapplied and. the plants often ilNldeeomerecovery a1'tctl'
several months. There is goode\t1dencethat one olVbeactions of smitrol 1s
reduction 1nphotosynthet:l.c acti-n.tr', However, the,¢hlorotic response ~rently
does not a.lways,persist long' filnbughto deplewcarbohytlrates to tq!, •. , ' .
lethal P9int~, The alll1trol in the tissue is bound 'or metabo11zed so that ,
eventually it is not presenti~ stif'ficient conc~ntr.tion to produce Chlo;'l)'"
Eiis. '-!hen p~ologically active COncentrations o,t.amitrolare lost before
carbohydrates are fully depleted, the plant recovers.
5ioo.e the rhizomes in an infested area are a~nt,the carbohydrat4p
reserves normally at a high level, and the dormant ~cr. very nwn.. oue., it
appeared prot1tSble to determine the factors that int'lue1)Ce the activityq.r
these buds.' If a means could be devised for lIiCJo.it.ng the activity of buds
on the rhizomes, tol'1ar treatments for thecontroJ. r:?fquackgrass would bjs,
IOOresuccessful tor a greater leaf area would be p",sent at time of tre~t..
Increased ntimberso£ shoots would ,81so allow for IOOZ'!'~apid depletion olthe
carbohydrate reserves than wouldo;therwise be the !lase. As an alternatiYll, ,
it the buds coUld be treated so that they would reilJaindormant indetinit~,
control measures might be devised IOOrereadily for the'weed would become'Jiillch
less competitive and a large portion of the rhizomes would probably die trom
nat~l causes withii1a year. 'Consequently, a, seri.e!S