Increasing Seed Yield in Big
Sagebrush by Mechanical and
Chemical Treatments
Kurt Elder, Brad Geary, Val Anderson, Joshua Nicholson, Rachel
Fugal and Aaron Nordin Brigham Young University, Provo, UT
Introduction
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


improve seed yields in established native
populations by reducing competition within
sagebrush stand
determine if chemical elimination of
competing shrubs increases seed yield over
natural stands
determine if mechanical elimination of
competing shrubs increases seed yield over
natural stands
determine if treatments are viable options for
seed production
Methods
The sights selected for this study was based on:
uniformity of height and density of shrub
 study area (50 acres or larger)
 first site is approximately 10 miles south of
Scipio along the I-15 corridor
 the second in Eureka at the entrance of little
Sahara

Treatments
mechanical thinning
 mechanical kill in 10 foot strips
 chemical thinning
 chemical kill in 10 foot strips
 control (natural stand undisturbed)

Mechanical Thin
Treatments were established by pulling a dixie harrow.
Mechanical Kill
To achieve this we pulled the dixie harrow over area three times.
Mechanical Kill
Chemical Thin
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Tebuthiuron (aka
Graslan, Spike).
28.9 gallons/acre
plant crown are
killed and is effective
on both large and
small stands.
public land
managers typically
use 2,4-D to control
sagebrush
Chemical Thin
Chemical Kill
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
Tebuthiuron (aka
Graslan, Spike)
maximum kill with rates
of 36 gallons/acre.
surfactant added to
maximize spread of
2,4-D
applied in 10 foot strips
comparable to the
mechanical thin and
kill treatments.
Chemical Kill
Seed Yield Results
gr of seed/50’²
2.5
A
AB
2
1.5
A
BC
1
A
C
C
A
A
A
CONTROL
MECH/THIN
0.5
MECH/KILL
CHEM/THIN
CHEM/KILL
0
Scipio
Sahara
% Kill Rate
100
93
80
75
80
60
77
48
71
62
48
Mech/Thin
Mech/Kill
40
Chem/Thin
20
0
Control
Chem/Kill
1
1
Scipio
Sahara
Frequency Sahara
3.5
3
2.5
2
CONTROL
MECH/THIN
1.5
MECH/KILL
1
CHEM/THIN
0.5
0
CHEM/KILL
alyssum
sagebrush
western
wheatgrass
crested
wheatgrass
cheatgrass
crypto
Cover Sahara
12
10
8
6
CONTROL
4
MECH/THIN
MECH/KILL
2
0
CHEM/THIN
CHEM/KILL
alyssum
sagebrush
western
wheatgrass
crested
wheatgrass
cheatgrass
cymopterus
Basal Sahara
4.5
4
3.5
3
2.5
CONTROL
2
MECH/THIN
1.5
MECH/KILL
1
CHEM/THIN
0.5
CHEM/KILL
0
soil
rock
litter
crypto
Frequency Scipio
3.5
3
2.5
2
1.5
1
0.5
0
CONTROL
MECH/THIN
MECH/KILL
CHEM/THIN
CHEM/KILL
Cover Scipio
16
14
12
10
8
6
4
2
0
CONTROL
MECH/THIN
MECH/KILL
CHEM/THIN
CHEM/KILL
Basal Scipio
4
3.5
3
2.5
2
CONTROL
1.5
MECH/THIN
1
MECH/KILL
CHEM/THIN
0.5
CHEM/KILL
0
soil
rock
litter
crypto
Preliminary Findings
 first
year of data suggest mechanical kill
to be advantageous
 over seeding with perennial herbaceous
mix to help with the understory and
reduce invasive species
 need multiple years of samples to
determine best treatment to use