IDENTIFICATION OF HERBICIDES FOR
USE IN NATIVE FORB SEED
PRODUCTION
Corey Ransom and Kim Edvarchuk
Objective
Identify herbicides for
weed management in
forb seed production.
- Astragalus filipies
- Dalea ornata
- Dalea searlsiae
- Crepis acuminata
Preliminary Response of Astragalus filipies
Prowl H2O
Outlook
Sencor
Olympus
Treflan
Kerb
Preemergence Herbicide Screening
Difficulty in achieving uniform germination has
prevented the generation of additional information
on preemergence herbicides.
With larger seed quantities, preemergence testing will
be done in field trials.
Research results for 2008 are from field evaluations of
postemergence herbicide tolerance in Astragalus
filipies and Dalea ornata.
Postemergence Herbicide Screening, 2008
Conducted on fields established in
2005 as transplants from conetainers.
Plants were spaced 0.5 m.
Herbicide treatments applied May 13,
2008.
Applications made with a shielded
bicycle sprayer at 20 gpa and 30
psi.
To account for variability, initial
height and width were measured
for every plant.
Herbicide Treatments on Astragalus filipies
Herbicide
Rates
lb ai/A
product
Prowl H2O
0.71
1.5 pt
Outlook
0.84
18.0 oz
Goal
0.25
1.0 pt
Chateau + NIS
0.064
2.0 oz
Sencor + NIS
0.5
0.66 lb
Buctril
0.25
1.0 pt
NIS at 0.25% v/v
2,4-DB
0.25
1.0 pt
MSO at 1.0% v/v
Transline
0.124
0.33 pt
Paramount + MSO
0.248
0.33 lb
Raptor + MSO
0.078
10.0 oz
• Around 15 cm tall at application.
• Injury evaluated May 23 (10 DAT) and July 25.
• Heights measured May 17 (initial) and June 19.
Pr
ow
lH
2O
O
ut
lo
ok
C
ha
G
o
te
au al
Se
+
nc NIS
or
+
NI
S
Bu
ct
ril
2,
4Pa
D
T
ra
ra B
m
n
ou sli
ne
nt
+
R
ap
M
S
to
r+ O
M
SO
Visual injury (%)
Astragalus Injury on May 23 in Response to Herbicides
100
80
60
40
20
0
• Transline injury high initially
Astragalus Injury on July 11 in Response to Herbicides
100
Visual injury (%)
80
60
40
20
Pr
ow
lH
2O
O
ut
lo
ok
C
ha
G
o
te
au al
Se
+
nc NIS
or
+
NI
S
Bu
ct
ril
2,
4Pa
D
T
ra
ra B
m
n
ou sli
ne
n
R t+
ap
M
S
to
r+ O
M
SO
0
• Transline injury maintained and Goal increased
•2,4-DB, Paramount, and Raptor increased
Astragalus Plant Height in Response to Herbicides
25
Plant height (cm)
20
15
10
5
0
l
e
k
il
d
te H2O loo Goa NIS NIS ctr 4-DB slin MSO MSO
a
t
+ r+
Bu 2, ran t + r +
tre owl Ou
u
o
n
a
n
c
r
o
T
e
U
P
at Sen
ou apt
h
m
R
C
ra
a
P
• Transline reduced plant height
Astragalus Plant Width in Response to Herbicides
18
16
Plant width (cm)
14
12
10
8
6
4
2
0
l
k
e
il
d
te H2O loo Goa NIS NIS ctr 4-DB slin MSO MSO
a
t
+ r+
Bu 2, ran t + r +
tre owl Ou
u
o
n
a
n
c
r
o
T
e
U
P
at Sen
ou apt
h
m
R
C
ra
a
P
• Transline reduced plant width
Relationship of Visual Ratings and Plant Height and Width
25
Change in plant width (cm)
Change in plant height (cm)
25
20
15
10
5
P > 0.0001
R2 = 0.47
0
20
15
10
5
P > 0.0001
R2 = 0.50
0
0
10
20
30
40
Injury (%)
50
60
70
80
0
10
20
30
40
Injury (%)
50
60
70
80
Herbicide Injury in Astragalus filipies
Transline
Paramount
Herbicide Treatments on Dalea ornata
Herbicide
Rates
lb ai/A
product
Sencor + NIS
0.5
0.66 lb
Buctril
0.25
1.0 pt
NIS at 0.25% v/v
Paramount + MSO
0.248
0.33 lb
MSO at 1.0% v/v
Raptor + MSO
0.078
10.0 oz
• Very little re-growth at the time of application.
•Injury evaluated May 23 (10 DAT) and July 11.
• Heights measured May 17 (initial) and June 19.
Herbicide Treatments on Dalea ornata
• No visual injury observed for
any herbicide treatment on
either evaluation date.
Dalea Plant Height in Response to Herbicides
40
Plant height (cm)
30
20
10
0
ted
a
e
tr
Un
r
co
n
Se
IS
+N
tril
c
Bu
t
un
o
ram
Pa
SO
M
+
r
pto
a
R
• No differences in plant height
SO
M
+
Dalea Plant Width in Response to Herbicides
70
Plant width (cm)
60
50
40
30
20
10
0
ted
a
e
tr
Un
or
nc
e
S
IS
N
+
il
ctr
u
B
t
un
o
ram
Pa
SO
M
+
r
pto
a
R
• No differences in plant width
SO
M
+
Conclusions
1. Once established, Astragalus filipies appears to
tolerate several herbicides.
2. Established Dalea ornata was not injured by
postemergence herbicide, but this may be due to
delayed breaking of dormancy.
3. There may be great potential to utilize herbicides
when plants are dormant.
4. Additional research will focus on the effects on seed
production following treatment with herbicides.
5. Another project will evaluate establishment
following Plateau applications.
Research support from:
USDI BLM Great Basin Restoration
Initiative, GBNPSIP, and
USDA FS Rocky Mountain Research
Station