Progress Report Series No. 83
Agricultural Experiment 
StationE..
AUBURN UNIVERSITY A
A SENSITIVE BIO-ASSAY for TWO
BIPYRIDYL QUATERNARY SALTS
H. H. FUNDERBURK JR. Asssant Botanis
JM. LAWRENCE, Assatae Fih Culurs
D ETFIiMI NAT]ION of residues bas beconie an
imp
1
ortant aspect of hierlbicidal research. Efforts
are contii l "i val being miade to incerease th e scmii
tix itx of knoxx n tests for thle chemnical allaixsis of
a larg(e mnl)(T of herbicides. Residu es tromi ay ia
tic herbicides are iisiallx v ery siai Iblecau se thle
herbicide mu11st be effectiv e in] silall qi ianitities
tisiialix 1.0 to 5.0 ppm )to be 
ecolloiicalix\ feasi-
ble.
'The comnpounmds 11'eh ei-_- ixrd u
dy hum dIi (iethx suilfate) ( paraq i mat ) arc newA
herbicides that control a num11ber of aq iatic wxeed
1
s
at exceecli1 glowLx rate's (0.5~ ppmn).
In prehninarx\ experiments, it was noticed that
these chemicals caused a greneral and finially a
complete chlorosis of sev eral aquoatic xx eeds. One
may, 1962
Smith, Director
uburn, Alabama
of the we eds that wxas conipletely bleached by
these herbicides wxas duck-weed (Lcnm a mninor U').
1)tickwed wxas subljectedl to sexveral rates of
lmtli herb)icidles amnd ov as tound1( to h~e senisitive( to
conicentrationls below 0.1 ppml. Rlepeated experi-
menits icicateci that concentrations as lowv ats
0.005 am dI 0.0075 ppi of cliqutat a nl paraua~t,
respectix\k. could b~e detected by assax iim wvith
duuckxxcccl.
Theli bio-assay is siniple, of short duration (96
than1 tile chemilical tests for these comupoids. It
is b ein g uitilIizted for thle deternili 1ationl of residui es
of1 ci(piat im c paraqmat in wxater and plants. Plains
are lili cerxxax to ad apt it to the ceterini I lath)]) of
residues of' th1ese cheicaezls in soil anid fish.
104--
CO TO D 10UTPRQA
of LX d I i ll( gro\I ( i ii Mid Mit ili ill i l ('O\ Ciii I I)it tit
hoiurs per (fit\ 101(1 at i t tipurlti itt of 1 SO l' Iti itc o if fli
abo\(. tl(.atljwllt . t1w \cscl \\as fillcd \ith dvo-Illormilk-d till)
\\iLtCl, itlid Hit. ihwk\\c(,d \\ios held ill t1w c\1wrii1wilt fol 7,
da\ . Tllc % ill t1w (viltel colltitilwd 0.005 ppill (liquat
and tll(. \ rscl oil tll(. rit-dit cootitincd 0.0075 ppin paraquat.
I li _dwi itt(,s of cither chcioicitl produo. cd cliloroi, of d1wk-
\\ (,(.d \\ ithill a ollich shortri r\pomin, period.
C
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