Vol. 16—1962 - NorthEastern Weed Science Society

OBJECTIVE
In 1958 an experiment was designed to evaluate the weed.
killing efficiency of two soil sterilants,diuron and simaziqe,
and to determine the relative extent of sU1"face washing after
application. No bi tumencove:r was used on'plots. 1
MATE}{IA.LS ANDMETHODS
Diur.on and simazine were each compared at 10, 16, 32 anct64
pounds active material per acre in 10 square-foot plots established
on sloping areas. Four replications of each rate were made,
with two replicates at one location and the other two each at
different locations. The treatments were applied on September 30,
1958. . . .
The plots were evaluated for vegetative control and downslope
damage outside the plot one year after application
(October 8, 1959). Vegetative control was rated as zero for no
effective control to 10 for complete weed control. Down-s;lope
damage was recorded as the number of feet below plots showing kill
of weeds. Ratings were made in October 1959, July 1960 and
August 1961. .
Table I: Amount of Diuron and Simazine Applied Per Acre on
Roadside Slopes in Central Connecticut
(September 30, 1958)
391
Lbs.
Lbs.
Treatment Lbs. Commercial Treatment ' . Lbs. Commercial
No. Active Product No. Active Product
D10 10 12.5 SlO 10 20.0
D16 16 20.0 816 16 32.0
D32 32 40.0 S32 32 64.0
D64 64 80.0 864, 64 128.0
\
*As "Karmex" diuron weed killer (80 per cent diuron wettable., .
powder).
**As "8imazine" 50-W (50 per cent simazine wettable powder).
Ten square-foot plots, four replications ot·each treatment.Replications
at three locations accentuated degree of slope and type
of watershed for the plots.
REPLICATESI & II - GlastonburY Route 17. Plots 2x5 feet across
the slope. Top of plots eight fee·t below guide rail cables of
fill slope. Manchester gravelly loamy sand, 35 per cent slope.
Growth at time of application was a sparse cover of sandbur, red
fescues, equisetum, tall fescues, some brambles, and broadleaf