Vol. 16—1962 - NorthEastern Weed Science Society

,10.1ng -2,4.,;iD (19), 2,4~5.T (4), silvex (4).
'Ha ...dnal - 2,4-D (34), dala.pon (26), amltrole' (13), 2,4,5-T (12),
.Uvex (11), mechanical .thads (10), oil (8), bu...ning (6).
7
The Hawaiian Agricultural E~ertment Station ...eported that a herbiv,orous
fi.h, TiLapia1llOa.amblca, has 8ive1'l excellent coril:rol of submened aquatic
weeds in canals,clitc:hes , pond', and ...eservoiri wttbpermanent wete... supplY.
This fish is used fo... food inlia.aii and the Philippines but is not hip~y
rega ...ded as afoocl or gsme fi8h, in South....n Unlted'S~.tes where preU:mi11.ry
tests have shown it to be not_It adapted..' ,
Lack of time prevents lIl1.aylng mot.'8about control methods. I ...e~nd
fw you... readinge recent publicllt10n by T. F. Hall (4) which contains an
excellent discussion of the naeure of aquatic weeclproblems and of contrdl and
management methods with an extensive review of lit~rature.
Future Prospects for Aquatic'Weed Control and Research
All signs point toward continued and probably much increased intereit
and activity in aquatic weed control. Wehave a barger backlog of unsa1:v,d
problems than in most other phue's of weed controL As water supplies become
more limiting and critical those aquatic weed problems will increase and
become more acute. The 38 replies to my questionnaire to State Agricultural
Experiment Stations reported a need for increasing research on aquatic weeds
from 10.5 to 88.5 man-years, eight times as many. The Federal agencies that
have shown an early interest i~ aquatic weed problems probably will con~lnue
and perhaps increase their present efforts.' ,
The replies' to the survey questionnaire were almost unanimous in
pointing out the need for a more' effective, less ei~nsive, longer lasti~s,
more easily applied aquatic herbicide that is safe>for fish, humans, livestock,
and wild game. I do not predict that many miracle herbicides thae
meet all those specifications will be found but the prospects seem pr~i~~ng
for much better herbicides than wanow have in coaaercial use. A totaldf
131 chemicals of the 854 compounds evaluated by Auburn University in the'
initial contract with the Agricultural Research Service gave 90 percent or
better control of representative aquatic weeds at 5 ppm. Sixteen of eh••e
chemicals proved safe for fish. Hany of these promising chemicals are~dw
undergoing secondary evaluation, and a few look extremely promising irifl~ld
tests. Probably additional promlsing aquatic herbiCides will be discovered
in two primary evaluation programs still underway at Auburn UniversIty.
Several chemical companies have recently establishe1:t sCt.'eening programs ,for
aquatic herbicides. That development shOuld great:ly increase our supply 'Of
promising aquatic herbicides far' 'further testing and ~evelopment. '"
Biological agents probably will play an important role in futurecorttrol
of aquatic weeds. The EntoDlologyResearch Division 'of the Agricultural""
Research Service i. now investigating in South Americ$ the feasibility of
introducing promising insect pests of alligatorweed-into the United State ••
A large freshwater snail, !!!!!.!!: cornuarietis L..,"us shown considerable
promise for control of certain submersed and floating weeds in Puerto Rico
and Florida in investigations conducted by the Agricultural Research Service,