Vol. 15—1961 - NorthEastern Weed Science Society

43".
by Leonard and Crafts (15) most effective absorption by the leaves can be
anticipated during the early summer prior to maximumcuticle development.
Four species which exhibit a relatively thick cuticle even early in the season
include
. considerable
oak, hickory, cherry and greenbrier.
resistance to stem-foliar sprays,
These species also show a
In contrast, black birch with
a thinner cuticle is most susceptible. Another possible deterent is the
bloom or glaucous covering on the leaves and twigs of certain species which
tends to resist wetting. Two species are of especial interest--whi te oak '
and sawbrier, both of which possess this char~cteristic and are extreIOOly
resistant. The texture of the bark as related to its ability to be wetted
may also be of importance. Young sprout growth of white ash and white oak
all have smooth stem surfaces. This may in part account for the resistant
nature
of these species.
In basal applica tiona it was also noted that whiteoak showed SOIOO
resistance, Here too, the stem texture may be important in that good rootkill
was obtained when the chemical was applied to the root-colJa r area.
From field evidence it would appear that better penetration of the chemical
occurs on stem bases with a roughened bark texture.
Root-suckering species such as sassafras and aspen frequently resurge
profusely following stem-foliar treatment. However, late summer applications
resulted in good root-kill of small aspen less than 61 high, but
greatly stimulated resurge of sumac. Mid to late summer basal or rootcollar
treatments have been effective on aspen as well as sumac. Susceptibility
during the summer may be correlated with active downward movement
of the chemical in the phloem at this time, especially into the highly
complex clonal root system of these species.
In summary, the critioal factor for getting root-kill is application
of adequate chemical around the root-collar region as in the basal or root ..
collar techniques. Breaking the bark surface to assure penetration greatly
increases effectiveness, as in the notch and frill techniques. In stemfoliage
applications, thorough coverage of bark and stems is essential.
However, total root-kill is less than with the other techniques in that certain
species are more resistant than others,
Present Vesetational Pattern: Its Stability and Conservation Values
The present vegetational pattern on much of the demonstration area is
essentially devoid of tall~growing trees. This infers that various shrub
communities predominate, depending upon their former abundance. In the shrub
community originally dominated by scattered tree sprouts, continuous shrub
borders occur on both sides of the line with scattered shrubby areas directly
under the wires, Herbaceous cover of grasses and goldenrods has increased,
especially where greenbrier has been removed.
In the sprout hardwoods cover type the tree sprouts have been removed
leaving continuous shrub borders of sweet peppe r bush, mountain laurel and
other species along the sides' of the lines and scattered shrubs such as blueberry
in the central strip, In the wetter areas, high bush blueberry, winterberry,
arrOWHood (Viburnum dentatum), and other valuable vuldlife species are
common. Also being maintained is a foot trail 8-10 1 wide directly under the
lines. It should be pointed out that although a favorable pattern has been
created in this area, the local abundance of greenbrier has modified the pattern,
especially under the wires. On ma~ rights-of-way low-growing species