Vol. 16—1962 - NorthEastern Weed Science Society

J:n Oswego at the. latter two times of applicationcmc at 4 or 6 pounds gave
better· eontrol of purslane than did CDAAat s:l.m1J.e.i'mea. Combinations of--these
two chemicals·at 3+3or 4+4 gave fair purslane control.
CIPC was generally inadequate in weed control at bOth locations regardless
of rate or timing. For some unexplained reason CIPC even performed poorly in
control of purslane. For purslane control CDAA+CIPCgave better performance
than either compound·used alone. CDAM-TCBC (Randmt-T) at either 4 or 6 pounds
gave excellent weed control at both locations at au times of application.
Purslane control was virtually complete at all times.
At harvest. CDAA+TCBC plots treated at the third stage were nearly devoid of
all weed species • However• an occasiOnal weed did apar. Growth was .slijbt
and weed foliage ·exhibited hormone-like symptoms. whioh indicates a longre!dual
from the TOBeportion. it should be noted again tha't' TCBCis automatically .
added at the rate of 10 and 15 pounds when 4 or 6 poUl!idsof CDAAequivalen:tiis
applied from the cODllllercial combination. t'1henever a chemical exhibits season
long activity there is inherent danger it may carry over and cause damage to the
succeeding crop if it is susceptible. Most vegetable crops including pot8toe's
fall in the susceptible class.
Su.ry
and Conclusions
Tests were conducted on seeded onions at two muck soU locations using-'
various chemical treatments. at different rates. combirlations and times oftr'eatment.
Rainfall and soU at these two locations differed markedly.
R,eD.1:ts.indicate that combinations of CDAA+TCBC give excellent control of
purs1ane and otber weed species over·a long period of time with only one aW1icati
.....
Whenapplied in the early stage of onion growth. CDAAapplications if 1'01­
lowed by heavy rains caused severe crop damage.
Whenapplied 1mmediately a:f'ter planting or in the crook stage CDEC.if
followed by rainfall gave crop inJury.
CIPC used alone faUed 1;0 give adequate weed control resardless of rate.
timing or rainfall.
CIPC+CDAAcombinations performed much like CDAAalone. with respect to crop
response. but 'Weedcontrol in general and control of purslane in particular
was IIlOreeffective with the combinat1lm than with CDAAalone.