Vol. 15—1961 - NorthEastern Weed Science Society

517.
The presence of both hardwood and conifer forests in the area, and the
intermixing of the two on many sites make blanket prescriptions for weed tree
control almost impossible. Each area must be carefully studied and a prescription
written that will favor the most valuable species for the site.
In all four sections of the count~, our objective as foresters is to
!Srow the tree species best suited to the site. We should never allow ourselves
to be misled into thinking that our objective in using herbicides is
to kill trees rather than to grow them. We cannot kill all undesirable weed
trees in a forest any more than a farmer can kill every weed in his corn,
wheat or soybean field. Yet, this does not stop the farmer from using
30,000,000 pounds of 2,4-D every year to double and triple his yields.
Regardless of whether we are using chemicals or some mechanical method
of release or site preparation, weed trees will return and will always be
with us. But, like the farmer, we can increase yields by obtaining a degree
of control with these mechanical and chemical methods. As many forest managers
have expressed it, we can buy a few critical years freedom from weed tree
competition to release our tree crop.
With the specific goal of growing trees clearly in mind, let us consider
the tools that are available and the techniques that sho1i promise for controlling
weed trees, particularly in the Northeastern area.
There is some confusion today on the subjects of weeding for site preparation
and weeding for release in regeneration work. Generally speaking,
our best chemical tool 2,4,5-Trichlorophenoxyacetic aCid, is not the best
answer for site preparation on areas supporting dense stands of hard to kill
species such as red maple (Acer rub rum) , ash (Fraxinus spp.), water oak
(Quercus nigra), laurel (KaIiiiia latifolia) and rhododendron (Rhododendron
maximum). Even if we could kill these species with 2,4,5-T at a per acre
rate that the value of the tree crop grown on the land could justify, the
dead stems would still be so thick that planting would be difficult and
costly. If direct seeding is to be used, herbicides do nothing toward preparing
a seedbed. In order for herbicides to be used successfully as a
site preparation measure, the underbrush should be made up predominantly of
susceptible species such as alder, hazel, gum (Nyssa sylvatica), oak, hickory
(Carya spp.), cher~ (l.'runus serotina) and birch (Betula spps ) and should be
sparse enough for easy planting.
A cheaper approach in the long run to regenerating these dense thickets
of difficult to kill species may be to mechanically clear them with bulldozers
equipped with ItKG"blades. Clearing by this method costs from sixteen to
twenty-five dollars per acre, but if the land, due to location or high site
index, is valuable and must be returned to production the cost may be justjfied.
Clearing in strips, or clearing without windrowing and. burning are means of
reducing the cost of mechanical clearing. You do not need to create a park-'
like condition for trees to grow.