Vol. 15—1961 - NorthEastern Weed Science Society

· 521.
HOt'l1ever"where more than a rew hundred stems per acre must be treated
a more rapid and cheaper ~tho.d that is gaininp in popularity in other
sections of the country is to' use the tree injector.
1). T,iliE Il\lJLCrING
~~st tree injectors are hollow cylinder tools about four feet long, with
a· cutting bit in one end. Either hand. operated or automatic triggering
mechanisms for releasing the chemical into the cut made by ~he bit are used.
The injector is thrown at the base of a tree at an angle .0£ approximately 600
with the ground. Injections are spaced around the base .of the tree at 1.5 to
2 inch intervals. Trees from.l inch to ten inches in diameter are best sui ted
to this treatment.
A solution of 20 pounds of 2,4,S-T low volatile ester, or more recently,
.. the combination of 2,4-D/2,4,5-T at this r 9te h~ve given 95% kills of oak,
: .hickory, cherry, maple and related specie sU3)(lO}. Care must be used in
making certain that the injections penetrate through the cambium layer of the
tree and into the inner wood. Failure to train tree injector crews in this
one technique can result in very poor resul ta.
Over 10,000 of these tree injectors have been sold to foresters in this
country. One commercial company in the south has treated over 20,000 acres
with tree injectors at a cost of approximately $lQ.OO per acre. This was on
land where up to 2000 stems per acre were treatedO).
In addition to being ideally suited to the weeding of hardwood stands
where individual stem treatment must be used tree injecting is also the most
effective treatment we have for species that are hard to kil~ by foliage sprays,
such as maple, ash and beech (Fagus grandifolia). This technique may be used
at any time of the year.
E. BASALSFRAYS
Basal spraying of small weed tree stems less than 1 inch in diameter is
a technique employed by some forest companies. The technique is slightly
different than that commonly used on utility rights-of-way. Rather than
wetting the bottom 12-18 inches of the stem, only the root collar zone is
wet to run-off in forest operations. Backpack sprayers equipped with three
foot extension wands are used. Pressures are kept very low, so that material
barely flows through the nozzle. Twelve to sixteen pounds of 2,4,5-T or
2,4-D and 2,4,,5-T per 100 gallons of diesel oil may be used. This treatment
is effective at any time of the year, but requires careful supervision to
insure that enough material is applied to obtain a good kill.
F. Cmlffili'JATIONThEATI1ENTS
No one of these herbicide application techniques will solve all the weed
tree problems in northeastern forests. Most forest companies have found that
'- their most effective control programs involve combinations of these techniques.
For example, a very effective program in the southeast today consists of
summer treatroonts with the tractor mounted mist blower to kill back understory
brush up to 30 feet in height.