Vol. 16—1962 - NorthEastern Weed Science Society

418
EarlY 'Chemical Trea~':,
. . .. .. ,:,;)
Chemical control of weed trees began in 1957, mostly with a one
:Per cent solution of 2,4,5-T in 011, applied by hand as a basal spray. Although
this was effective, it was laborious. PrOlllllling 1958 trials with
dry fenuron in a sawdust carrie:r;"irid later with the 25 per cent fenuron
pelleted formulation, led to 'an~l!insive experiment in 1959.
An 18-acre piece of Illi~ forest (the:2-Durgin field) was chosen
for this experiment. Applications were made in May 1959. The fenuron pellets
were applied in a heel depression at the base of each weed tree or clump. The
rate was one-quarter ounce per tree or clump (a slightly heaping domestic teaspoon
or 1.9 grams of the basic chemical). A few weed trees were chopped down,
rather than treated', where they seemed too close to" desirable trees for sllote
chemical use.
'",
Altbough the summerwu very dry, wide's~ad defoliation was o~erved
after the fall rains began, jus't before frost .1Jul-:jJ:lg the winter and e~iy
spring of 1960, neighboring conifers showed somebro'wning of the needle tips.
However, they recovered during 1960, and grew with increased vigor. Seedlings
more than doubled their top growtb. Most of the ~'d.trees showed ad~tional
defoliatIon andtlnally died. Mantof tL.:Jse whichlu.d', not die continueddafoliating
in 1961. A number otthe weed trees tha~'surVlved into 1961 we~e
multi-stelll!lledbirch or stump sprouts of swampmaplflNl.,The explanation tor the
birch survival seems to be eUherthat more chemiclil'should have been used per
clump, or It should have been spread over more are!',., With the swampmaple
stumps, apparently the' feeder roOts, were too far ~the point where tba
chemical was applied. -, ,
'[f'
A group of profession8.ltoresters who in:8;Pectedthis tract on July
25, 1961, considered it an adequate job of forest weeding.
,me}260
Experiments
Beginning in July 1960, further chemical weeding was lmdertaken on
about 35 acres of a 50-acre phce (the l-Proctor lot). On this land there ,
were many valuable hardwoods intermixed with small pines. Since the selecti v­
ity of the 1959fmmronapplicat1en.had not beenetlmp1etely established, ';the
program started lIIIl1t1lywith 2,4, 5-'tapplied in fri~.; To redllce tranepgrtation
and labor,jelliedsod1uma1"senite was shortl:f'!Used tor the weed 'tr,"e~ "
close to desirable ones • ' ;j , "
As continUedobservatlotFof the 1959 f~,a;pplicationslnai¢~ed: ,"
its safety to nearby untreated t1'eelt" more and, IIIOre't'.ehUron,was applied '4\lring ,
~:~u:~:::so~P~~~d "~~ ~:~::eer:a:t::l'b~~h:~~hOd. ,Mo~t rJf tlie" -
....._~..'.~ .,
Repeated inspections of this area in 196J..1n4.1catethat,,-tbe 2:'-4~~,lT,
treatment wasettect1 "e 'without n6tleeable re-sprOttt1n~. Tr~es -tJ:"eated With _-
sodium arsenitere-sprouted severely, even where the'stems w.ere,kiUedj liut J
many of the larger trees did not ~e at all. ,8 - '