Vol. 51—1997 - NorthEastern Weed Science Society

98
However it .ncreased the control of forsythia roots. Mixing 2.0% Surflan in Spin Out provided
control of t e roots of all species that was similar to 2.0% Surflan in paint.
The e is a definite difference in how the different species respond to different root control
treatments. Extensive studies will have to be conducted to determine the type and level of treatment
needed for ach individual species. The alternative is to select single high rate, or combination of
products, t t will control circling roots in all species. In all of the studies conducted, Surflan has
provided c trol of circling roots at least as good as Spin Out, the industry standard. There is still
much work that needs to be done regarding rates, carriers, longevity I decomposition, and fate in
the enviro ent, but its potential use hasbeen demonstrated.
Table 1. T e average circling root rating and top weight of pyracantha planted on July 1, 1995
in 0 2.5 gallon nursery containers. Treatments were painted on the inside of the
c ntainers. Circling roots were rated on November 14, 1995. Root circling was rated
o a scale of 1 to 10, with 1=no circling roots and 10=many circling roots. Plants
w re harvested and weighed November 15. The average of 12 plants per treatment is
p esented.1L
Treatment
Control
Latex Paint
Spin Out
Surflan (0.1%)
Surflan (0.25%)
Surflan (0.5%)
Surflan (2.0%)
Surflan (4.0%)
Root Circling
9.8 a
10.0 a
2.3 d
6.8 b
4.4 c
2.7 d
1.8 e
1.0 f
Top Weight (g)
209 c
209 c
260 a
246 ab
230 ab
234 abe
224 be
230 abc
lL
cans within columns, followed by the same letter, do not differ at the 5% level of
.gnificance (DMRT).