Vol. 16—1962 - NorthEastern Weed Science Society

256
Annual gl'ass, avel'sging2,,8 planbs'-pel',.quare foot in untl'ea
ted plots, ciid not seriou.~.1 oompete w$.:ool'n fol' mohtW"t
and nutiiients. ,&ooedleaf we.df" on phe obh... ' J:!.and, pl'inoipally
Bl'assioa leie L., avel'aging 20.$ plants pel' squal'e foot in untl'eated
p 0 s, 'sharpJ,.y I'eduoe;dryields when ~l1didste hel'bioidu
gave less than 80 pel'cent oontl'ol. six pounds of Niagal'a $778
pel' aOl'e did not diffel' signifioantly fl'OM 8 pounds in bl'oadleaf
weed oontrol, Table 3. Ten p,OJil'ldsof 81thel' R-3408 01' R-3400 gave
signifioantly bettel' bl'oadle"at\teedcontl'ol than 5 pounds of 81thel'
hel'bic1de. Ten pounds pel' aOl'e of R-3441 dld not diffel' signitlcellUyfrom
;1.0,pound. of R-3408, Table 3. '~o pounds per 80N of
dipnellamld gaveun.a tistaotoU;.o.ontl'ol ofB~ue1ce species, ' buth
gave fa1~ ooritl'ol of I'agweed.
Hel'b10ides giving signifioantly highest annual gl'ass oontrol
inoluded Dupont 326 at 3 and 6~po~d aOl'e I'ates, 3 pounds ot Dupont
326 pel' aOl'e plus 2 pounds ofd!phenamid, 2 pounds of atl'uine, and
8 pounds ot Niagal'a 5778. Eight pounds of Niegal'a $778 pel' acre did
not' ,d,l,:!'fel' Sl 8Pl,fl,O$ntl,Y f~DP1,'?,', pounds, ofcUlpbecamid, Table 4.
R-3490 and R".3408 did not ~i,tf.~ a1gnifioa~.:l.~,1n annual ~a.. :'
oontl'ol, Tabl,e 4. .' :' :
Plo'ts'that bad I',eoeivea ,a6 pound pel' ,~re nteof Dupon~, 326
hads1gn1tican~ly, fewer cO-Nlplanta per 2S f.-t· of row than 'plo:ts
reoeiving any other tl'estment', 'Table 5. Plo.fiJ t'ut had received
a 3 pound pel' aCl'e rate of Dupont 326 elther' alone 01' in oombinatlonwlth
2 pounds of dlphe~d: had s1gnit\l~ly fewel' oom:planbs
per 25 f~et 'of row than all ,l'~1nlngtreatJl1mts except 2 po.und~ .'. .
per acre,of dlphenamid alone. ,;t!eno6, in -'p~" ot, t.he neal' lI18X~uil'
annua'l weed con+-:roloptdned,.3, pounds pel' '~ 'or Dupont 326 't. "
too high a I'ate fur pl'eemel'genoe applica tion in sweet oOl'n on~dy
loam soils.
Summal'Yand Conclusions
Fol' nine weeks., aftel' sp:pl1oa ti on, 2 pouods, per aore of " '
atl'ulne (wettable powder), 3:.apd 6 pounds ot Pupont 326, and 6
and,8 pounds; of N1agua 5778 iave oomplete opntro1 ot annual ",
bl'oadleat weeds in, sweet cO""o'- Two pounds p,1' aore, of a tl'szine, 6
pounds of DUpont 326, 3 pouAds of Dupont 326 with 01' wlthout.2 '
pounds of diphenamid, and 8 pounds of Niagara 5778 gave complete
oontl'ol or annual gl'ssses for nirleweeks aft~~ applioation.
Compal'ed to all othel' h;l'blcldes tested,i6 pounds pe~ a01'8 of
Dupont 326 significantly I'eduoed stand of oorn. Three pounds pel'
aCl'e of Dupont 326, 2 pounds of diphenamid, and a mixtUl'e of 3
pounds of Dupont 326 and 2 pounds of diphenatdld- Signifioantly'--
reduceci corn ,stand co~al'ed.,to 2 P,oun,ds ,0,fatpaz1ne, 6 and 8 pom,'d8
of Niagara $778, and'~ and, ·10 p,Ounds of e1theI! ;Ft-3400 01' ,R...34.l1.
COl'n stand in plots recei v:k1geither 1 pound of Banvel T or 3 pounds