Vol. 16—1962 - NorthEastern Weed Science Society

FURTHEROBSERVATIONS ONCONTROL OF THECQvJMON BRAKE,TERIDIVMAQUILINUML.,
IN LaolBUSHBLUEBERRIES WITHPOLYBORCHLORATEl
, ,i: ',d
W. J. Lord 'ead J. S. BaUey:z.,
15.3
One of the chief concerns of thAlmanagera ofloffbush blueberry areas il
the control of weed apecies wh:l.ch·~t~ out theblu ..... rles and seriously
interfere with harveating. In 194'8"'. weed survey in'r~b.e lowbush blueberry
fields in the Granville-Blandford area of Massachuaetts revealed that the
cOlllllonbrake', 'l8r1dlum aguilinum t ..,(:h a serious weed in many places (1).
Previous work (1) has shown that 400 to 600 pounds per acr. of polyborchlorate
applied'l,)J;ior to "burn" will et£ectively control the cOllllllonbrake,
but this matel'ial'injure. the blueberries. Whenthe polyborchlorate was
applied in the fall previous to the year of burn, recovery of the blueberry
plant. was better than when it Was applied in the .pt~ng'after the burn. T~
difference waa highly significant. The difference in brake kill betweent6e
spring and fall applications was not significant. Following either fall 1957
or spring 1958appltcations the number of brake. on'the ~lots was less tn
1959 than 1958, 1ndtcating'a carry-oVer of the chem~c&1.
. \
.. , ...'
Whether,ornot'brake're1nfestadon occur. andhoWfa.t the blueberry
plants re-establish them.elves fotlawtng the application ofpolyborchlorat~'
are questions of vital importance to the grower. 'ThIJ'work reported here wall
undertaken to answer these qu.stio~••
Method' ilndMaterids'" ;
In the .fall of 1957, six s~at. rod plots were laid· out at each of three
locations. Polyborchlorate was 'appU~ at 400, ,500,. and 600 pounds per acre
on half the plots at each location On'November13, 1957 and on the other half
April 25, 1958. Before treatment .;jquare-yarcls~t"on of each plot was '
measured and the brakes in each of these squares~ouPtedr The number of ,
blueberry plants 'waa counted on f~r,l-foot squates ~hOsen at random on ea¢&
plot. On August '7, 1958 post-treatment counts of brakes were made and on .
July 14, 1959, July 12, 1960, and September 13, 1961, counts of both brake.
and blueberry plants were made. No ~ounta of bluebeiry planta could be maa.
in 1958 because the fields were burned. From these data the percentage kill
of brakea and ,the percentage recovery of blueberrYi~ants were calculated •.
,. " i", .,',
For stati.tical treatment b1'a~lysis of variande the percentage. of
brake control'were transformed to.nsles (3) and the 'percentages of blueberry
plant recovery to rarik1t valu8.(2). The mean' irt" compared by the .
method of J .S. '!'Ukeyas modified iiy Snedecor (3) .~lIUference necessatf
for significance is expressed as D rather than LSD.' ...". , ,
lContribution No. 1329, Masiachu•• tt. Agricultural EXperiment Station, Amhe.ret
.:.