Vol. 16—1962 - NorthEastern Weed Science Society

411
RESULTS
ireatmentettect was dete1"Jld.JJtdby measuriDg'l2,3concentric circul..­
plots ear~ in september the yee atter sprq.i%1g. tow 1:xt'UBhwas measured
on .COl_acre plots (radius 3.72 teet), high brUBhbn .005 acre plots
(radius 8.33 teet), and trees on:.~.acre plots (Mdius 26.3 teet). The
plots 1ieI'e mechanically locatedbyconpass andpa(fbg; .
The first .two matching test. were made in JlaSftohusetts in a white
pille-hudwood stem less than tCll"V teet tall. b majCll" hardwood speo!es
present were ~e;y b1roh and red lI8P1e with SOJlle oa1t.aDd shrubs like blueoberry
and hucklel;lerl7. The hard1llOCldswere for the'lIOSt part taller and ~e
vigorous than the pine.' .
,
Twopounds 2, 4, ' ...T in 4.' gallons ot No. I ruel oil per acre was'·
matohedagainst two pounds 2, 4, 5-T in 4.' gallomi: of water. As shown'b.
Table 2, the water JIlixture prove4to be less etfecUve than the matching:1,,:11
JIlixture and was less eftective than 8Zl;Yother herbiCide mixture testel!. •
Twenty-eight per cent ot the low brush on Test 1 showed no damage (Table 2).
This \Uldamagedvegetation was huok1eberry and blue1Jerr;v'. The undamaged :J,ow
brush in Test 6 was maleberry and1aurel. Huclde1:«"rY, blueberry, malebe1'1'Y,
and la\l1'el (all ericaceous shrubs) proved resistant::1n every test where they
ooourred. In all tests control o1'hard\1lOCldsin the: tree olass (2" DBH_up)
was not as good as control of the ;Lesser vegetatioD; Jmly ot these trees were
beyond the eftective height range at the machines ,.ed. In dense stands Ithe
lower branohes of trees were ldJ.1ed, but the tope 1JIIK'oeleftintact, bee_a
spread Of the mist was checked on hitting the bottm ot the tree orO\UlB. IA
second spraying would do more daJDageor probably kS1l the tree it it ere :'less
than thirty feet tall. \.
İ
The second set ot matching tests was conduete4·f~in:New Hampshire so'1lhat
the sensitivity ot red spruce and balsam fir tOthe:herbicides could be judged.
Tests we:t'econduetel! in stands w:I:thpille, hemlock,'Jred spruce, and balsaDlfir
JIlixed with hardwoods whioh were general~ overt~the softwoods. ~ of
the trees Vlere less than forty feet tall. < .I •
Test 3, too pounds 2, 4, ' ..T :I.n 4.5 gallonsot No.' 2 diesel oil was
matched ag~t Test 4, two pounds 2, 4, 5-T in on8'!gallon of No. 1 tuel bl1
and 3.5 gallons of water per acre. Here againthelllittture with straight o~ .
as a carrier was substantially superior to that oon'llWting part water (1'&1'1e2).
On the other hand, the mixt\l1'e with the oil-water oarrier, Test 4, gave '.
better control than the mixture 1I:I.thstraight water; as the oarrier, Test '2.
It is probably safe ..to say the JIIOre oil there 1s. 1:11' the' JIlixture, the better
is the hardwoodoontrol.
Somedamage to cOZlifers waS observed on all t.he!test areas. JOOst I"
damage tooon:l.fers was observed on Test 3, the area''ti:re&ted with the diee.1
oil mixt\l1'e. Six small suppressed pine were foum'iaad:on the plots taken
in this area. This damage probably occurred, beoause diesel oil, being less
.i;;
I) .