Vol. 15—1961 - NorthEastern Weed Science Society

508.
distance was achieved. All subSequent strips ,long the road were sprayed
without the nozzle attac~nt. The truck moved at ..fi."e ·mUes per hour
spraying on both the forward and backward pass untU all the mixture for a
given 'strip was used up. Sane softwoods were in the direct path of·the spray
blast, and some large hardwood intercepted the air stream and decreased -the
effective distance of penetration. In this teat, good control of hardwoods
resulted 1$0 1 back from the road where the machine trawled.
THEAREASTREATEDAND. CONDITIONS DllUNGTREATMElfl'
The area selected for treatment with the truck-mounted mist blower was
a stand of eastern white pine and hardwoods which had suffered. sever blowd.ownin
the'1938 hurricane. On the· pound was a d.e.nsemixture of pine and
hardwoods about 20' tall with occ&sioDal larger trees of varying size up to
two feet in ~eter which sur.vi ved the hurricane. The vegetation selected
tor spraying was nearly all less than 20' tall, so that the machine could
throw the material at a more nearly horizontal angle to obtain maxim\D
penetration. Hardwoods on the area. were predominantlY' birches, maples, and
oaks. A small amount of hemlock was also present.
Eight plots were located in pairs, one on each side of the road, to test
the four spray mixtures already' described and. the method of applying them.
Conditions for the test were not ideal. Spra1ing was done at an early hour
to get still weather, but the wind ranged from $ to 10 miles per hour limiting
penetration' on the windward side and. carrying the _tierial too quickly away
on the leeward sides. Arborists usuallY' limit their work "ith this machine
to still conditions at daybreak, at night, and other times when the air is
quiet.
RF.,sULTSFROMTHETRUCK-MOOOFDMISTBLarlING
There was little difference in hardlrood control between one-pound and
two-pound concentrations of 2, 4, 5-08 and Kuron. Kuron was less effeotive
than 2, 4, $-OS in killing large trees. Pine in the direct blast of the spray
showed some damage after three weeks, but this was very difficult to d.etect a
year after the spra1ing. Hemlock in the direct blast showed peater damage,
and a few of the damaged terminal buds did not put out new growth the foJ-low.
ing year. Parts of these trees were soaked to the running off point with
spray. Scattered cull hardwood trees UP to two feet in diameter were killed.
The line of ld..ll~g spray peDetration was fairly sharp, and sane trees at
ma~d.Il1um penetration dis.tance were damaged on one side only. White oaks,
wM.ch proved most susceptible in all tests were killed beyond the line of
~eneral killing pelletration. The tops of larger oak trees above the general
crown canopy beyond. this line showed some damage.
Sane sprouting occurred, perhaps because the tissues died before they
could carry the chemical to the roots. Spray concentirations were strong and
fo:liage brOl-Tt1j.ngwas very rapid. The 1011brush had most sprouting with
progress:\. ve"'--;r:ess sprouting on larger trees. 0nJ.Tone area had sprouts on
t:t"l;les2 ilj~}r.es or more at breast height. Sprouting does not appear to be a
serious obs'(;acle to barclwood control with mist blowers.