Barlely Seed Treatment, 1994
R.L. Dovel and G. Chilcote'
Introduction
Seed treatment is an environmentally safe method of protecting small
grains from seed and soil borne pathogens. The use of seed treatments for
control of a number of smut species is universally accepted in the industry.
New products are being developed for controlling other pathogens as well.
Three trials were established in Klamath County to examine several new
products for effectiveness against local diseases and pests.
Baytan is a fungicidal seed treatment which may be effective in controlling early season infestation by barley stripe rust. Barley stripe rust has been
introduced into the United States from Europe and was found in neighboring
states in 1993. Baytan was included in the trial to test its effectiveness against
this new fungal organism if it appeared in the Klamath Basin.
Imazalyl has been an effective control against common root rot in other
areas, but has not been tested in the Klamath Basin. Common root rot is a
continuing problem in the Klamath Basin and is especially damaging in continuously cropped small grains. This pathogen is favored by wet, cold springs
and improper irrigation management.
Kodiak is a bacterial inoculant which is antagonistic to a number of soil
borne pathogens. The bacteria grows along the root of the plant and inhibits
infection ofthe root by fungal pathogens. The bacterial spores are resistant to
most fungicidal seed treatments and it is recommended that the product be
used in conjunction with chemical seed treatments. This product has not been
tested in the Klamath Basin.
Gaucho is a systemic insecticide which will soon be labeled for use as a
seed treatment on small grains. It has proven very effective in control of
Russian wheat aphid and other pests. There is also some indication that it
1/ Associate Professor; Professor, and Research Technician, respectively, Oregon State University,
Klamath Experiment Station, Klamath Falls, OR.
Acknowledgments: Henze' Farms provided the off-station sites and crop care.
Klamath Experiment Station 149
Barlely Seed Treatment, 1994
may be effective in controlling Hession fly, which is similar to the wheat stem
maggot (WSM), a significant pest of grain in Klamath County. The use ofthe
chemical as labeled has little impact on the environment because the use of a
seed treatment delivers a very small amount of material in a way that is
relatively unavailable to non-target species and Gaucho has a relatively low
acute toxicity (very high LD 50 ) in non-target species. It is not known if
Gaucho seed treatment on small grains is effective in controlling WSM.
Procedures
The trial at KES was established on land planted to potatoes the previous year. Soils at the station include Poe, Fordney, and Ho sley series, all of
which have a fine-loamy to sandy texture, and are moderately deep and
somewhat poorly drained. The off-station trials were on very deep, poorly
drained, lake bottom soils with high organic matter content. These fields are
cropped in spring cereals continuously. All plots at KES were irrigated by a
solid set sprinkler irrigation system. Only one organic soil site was irrigated by
sprinkler irrigation after planting. Both organic soil sites were flood irrigated
prior to planting.
Seed of Gus barley was treated with 8 seed treatments prior to planting.
Treatments included: two rates ofBaytan and Captan, two rates of Imazalyl
and RTU, one Kodiak treatment, two rates of Gaucho and RTU, and one
RTU treatment, which is the industry standard. All seed treatment rates are
reported in ounce product/cwt of seed in Table 1. All trials were arranged in
a randomized complete block design with four replications. The trial at KES
was planted on April 22. Irrigated and unirrigated organic soil sites were
planted on May 13 and 16, respectively. Seed was planted to a depth of one
inch at a seeding rate of 100 lb/acre. All plots were fertilized with 100 lb N,
60 lb P2 O5 , and 44 lb S/acre at time of seeding. Plots measured 5 x 20 feet,
with a row spacing of 6 inches (10 rows). At KES, bromoxynil and MCPA
were applied at labeled rates to control broadleaf weeds. Weed control at
organic soil sites was achieved with a mixture of 2,4-D and Banvel. Plots
were harvested using a plot combine with a 5-foot wide header. Grain yield
was recorded for all plots. Test weight, percent plumps, and percent thins
were measured in only one replication.
150 Klamath Experiment Station
Barlely Seed Treatment, 1994
111■1111•1•111M111111■11•1
Results and
Discussion
Barley stripe rust was not evident in Oregon in 1994 and the effectiveness of B aytan against this pest was not evaluated. In the absence of barley
stripe rust or other rust species, yields of plots treated with Baytan were not
significantly different than the control, RTU VT, at any test site (Tables 1-3).
The spring of 1994 was one of the driest on record and common root rot
infestation was very low. There was no significant difference in grain yield or
quality parameters between Imazalyl or Kodiak treated plots and the RTU
VT treated control at any test site (Tables 1-3).
Yields of Gaucho treated plots were significantly higher than the control
at both irrigated sites (Tables 1 and 2) but not at the unirrigated site (Table 3).
Although infestation ofwheat stem maggot was very light in 1994, there was a
low level of Russian wheat aphid at the experiment station and a high level of
infestation of corn leaf aphids at the irrigated organic soil site. It appears that
the Gaucho seed treatment was effective in maintaining these insects at lower
levels than the non-insecticide treatments, resulting in higher yields. Grain
quality parameters such as test weight and percent plumps (percent above 6/
64 screen) were also higher for the Gaucho treatment than the control at the
two organic soil sites (Tables 2 and 3).
Further testing is needed to determine the effectiveness of these seed
treatments against the various pest species in the Klamath Basin.
Klamath Experiment Station
151
Barlely Seed Treatment, 1994
Table 1.
Entry
Effect of seed treatment on grain yield and quality of irrigated Gus barley
planted in mineral soil in Klamath County, OR, 1994.
Treatment
Rate
Test
weight
Yield
oz/cwt
lb/A
lb/bu
Thins
Heading
6/64 5.5/64 Pan Lodge Height date
%
inches
Julian
1
2
Baytan/Captan
Baytan/Captan
0.75/2.0
1.25/2.0
8080
8070
53.3
53.0
91.8
92.3
6.3
6.1
1.9
1.6
0
0
33
34
178
178
3
4
Imazalyl/RTU VT
Imazalyl/RTU VT
0.25/5.0
0.05/5.0
8200
8100
53.3
53.0
91.2
91.2
6.8
6.7
2.0
2.1
0
0
36
34
178
178
5
Kodiak
0.1
8180
53.0
92.1
6.2
1.7
0
35
178
6
7
Gaucho
Gaucho
2.0
4.0
8610
8540
52.6
53.5
91.4
93.3
6.6
5.3
2.0
1.3
0
0
35
35
178
178
8
Control - RTU VT
5.0
7930
53.3
91.3
6.8
1.9
0
35
178
8210
4.4
530
53.1
1.0
0.8
91.8
1.9
2.5
6.4
20
1.8
1.8
27
0.7
0
0
0
35
5.1
2.6
178
0
0
Mean
CV (%)
LSD (0.05)
152 Klamath Experiment Station
Barlely Seed Treatment, 1994
Table 2.
Effect of seed treatment on grain yield and quality of irrigated Gus barley
planted in organic soil in Klamath County, OR, 1994.
Entry Treatment
6/64
Thins
5.5/64
51.3
51.3
93.9
94.2
4.6
4.4
1.4
1.4
Rate
Yield
Test
weight
oz/cwt
lb/A
lb/bu
Pan
1
2
Baytan/Captan
0.75/2.0
Baytan/Captan
1.25/2.0
5840
6030
3
4
Imazalyl/RTU VT
Imazalyl/RTU VT
0.25/5.0
0.50/5.0
5850
5800
51.1
51.0
93.4
93.2
5.0
5.3
1.6
1.5
5
Kodiak
0.1
6090
51.8
94.4
4.4
1.3
6
7
Gaucho
Gaucho
2.0
4.0
6990
7140
52.5
52.6
97.0
96.8
2.3
2.6
0.6
0.6
8
Control - RTU VT
5.0
5990
51.0
93.3
5.1
1.6
6210
4.6
420
51.6
1.1
0.8
94.5
1.0
1.5
4.2
16.0
1.0
1.3
26.0
0.5
Mean
CV (%)
LSD (0.05)
Klamath Experiment Station 153
Barlely Seed Treatment, 1994
Table 3.
Effect of seed treatment on grain yield and quality of unirrigated Gus barley
planted in organic soil in Klamath County, OR, 1994.
Entry
Treatment
Rate
Yield
Test
weight
oz/cwt
lb/A
lb/bu
6/64
Thins
5.5/64 Pan
1
2
Baytan/Captan
Baytan/Captan
0.75/2.0
1.25/2.0
3850
4420
51.4
51.5
94.8
95.9
4.0
3.1
1.2
0.9
3
4
Imazalyl/RTU VT
Imazalyl/RTU VT
0.25/5.0
0.50/5.0
4030
4080
51.0
51.1
95.6
95.4
3.4
3.4
1.0
1.1
5
Kodiak
0.1
4130
50.9
95.7
3.2
1.0
6
7
Gaucho
Gaucho
2.0
4.0
3720
4570
52.0
51.6
96.5
96.4
2.8
2.8
0.7
0.8
8
Control - RTU VT
5.0
4210
51.1
95.7
3.4
1.0
4130
8.4
510
51.3
0.9
0.7
95.8
0.5
0.7
3.3
9.8
0.5
1.0
21.0
0.3
Mean
CV (%)
LSD (0.05)
154 Klamath Experiment Station