Vol. 15—1961 - NorthEastern Weed Science Society

CONSIDERATIONS REG.4RDIl\"G THEUSEOF AQUATHOL IN POTABLEWATERSHEDS
H. L. Lindaberry
The first consideration is -- what is Aquathol? As many of you inatten­
~e-here may not follow aquatic weed control closely, I will try to give
you a.brief background. Aquathol is the trade name for an organic contact
herbicide. The active ingredient in this product is thedisodium salt of
3,6 endoxohexahydrophthalic acid, more commonly referred to as disodium
endothal. Aquathol was developed for the control of various submerged and
emergent aquatic weeds~8 well as for certain algae. The structural formula
for disodium endothal :18: .~ .
1'
1C01l1a
1 ......I . CONa
""J/
II
C
The word endothal alone is the commonterm applied to the 3,6 endoxohexahydrophthalic
acid.
Disodium endothal 1s soluble in water to the extent of about 25% and also
--
it is insoluble in most organic solvents. It is currently commercially
available for use on red beets, sugar beets, spinach, turf, and for harvest
aid uses, in addition to aquatic weed control. The two principle
formulations commercially available for aquatics are the 2 lb. per gaL-;
water solution of disodium endothal, sold under the trade name, Aguathol,
and the 5% granular product impregnated on 8-16 mesh attapulgite clay, ,
available as Aguathol G. .
The next consideration is -- why use Aquathol? Summarized) the reasons
are:
1. Gives good control of many aquatic weeds.
2. Rapid disappearance.
3.
4.
Wide margin of safety to fish and other aquatic
Low chronic level of toxicity.
fauna.
5. Relative safety to the applieato~
label are followed.)
(1f directions on
6. Economy.
'To go into detail on the reasons that 1 have just summarized, first of all,
Aquatbol controls many of the major aquatic weed problems found in the
Eastern and Central United States. It is particularly effective against
most potamogeton species, as well as milfeil, coontail, waterstar grass,
Naias, duckweed) zannichellia, burrweed, and wild celery. As for algae
control, good knockdown, especially on floating mats can generally be
obtained, but in some instances where favorable conditions have been
pr esent , regrowth has been a problem~ due to the ShOTt T'asidual acHt")"Cl'
of disodium endothal.