17
Pasture Grass Variety Trials
R.L. Dovel and J. Rainey'
INTRODUCTION
Irrigated pastures cover over 95,000 acres in Klamath County and
provide summer grazing for over 100,000 cattle each year. The currently
recommended grass variety for irrigated pastures is Alta tall fescue,
which was released in the late 1940's. New cultivars developed since
that time need to be assessed for adaptation to the Klamath Basin. The
acquisition of new germplasm from forage breeding programs in New
Zealand and Australia add further emphasis to the development of a
forage variety screening program in the Klamath Basin.
Two variety trials were established in August, 1988 to examine the
relative forage production of commercially available tall fescue and
orchardgrass varieties. Another trial was established examining hybrids
of bluebunch wheatgrass and quackgrass compared to a locally acquired
selection of quackgrass. A substantial acreage of quackgrass pasture
is grown as hay or pasture in the Klamath Basin. The identification
of a less weedy hybrid that is better adapted to both hay and pasture
production could be very beneficial.
METHODS
All three trials were established on sandy mineral soil at the
Klamath Experiment Station in August, 1988. All trials were arranged
in a randomized complete block design with four replications. Soil
samples were analyzed and appropriate fertilizer was applied prior to
planting. Seed was drilled to a depth of 1/4 inch using a modified
Kincaid plot drill. Orchardgrass was seeded at a rate of 15 lbs/A.
Tall fescue varieties were seeded at 12 lbs/A. Quackgrass-bluebunch
wheatgrass selections and crosses were seeded at a rate of 10 lbs/A.
Plots were 5 x 20 feet with 3-foot wide alleyways. Irrigation was
supplied by a solid set sprinkler system during establishment.
The plants were allowed to grow uncut through the first growing
season. Three harvests were taken in 1989 when plants began to flower.
Plots were harvested with a flail harvester. All yields are reported on
a dry weight basis.
1/ Assistant Professor, Biological Sciences Research Technician,
respectively, Klamath Experiment Station.
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RESULTS
Tall Fescue
Tall fescue had the best seedling vigor of the grass species
established in 1988. All varieties established well and tended to
out-compete most weeds, with the notable exception of several mustard
species. Average yield of tall fescue was higher than any other forage
grass. It also appears that forage yield of this species is less
dependent on N fertilization than orchardgrass.
There was no significant difference in total forage yield between
tall fescue cultivars in the first year of this trial (Table 1). Tall
fescue is the recommended grass species for irrigated pastures due to
ease of establishment, forage production, weed suppression, and stand
longevity.
Orchardgrass
Orion produced significantly more forage than any other orchardgrass
variety in the trial, yielding over 8 tons/A in 1989 (Table 2). All
varieties established fairly well; however, they had much less seedling
vigor than tall fescue and weed invasion was a problem in establishment.
Orchardgrass showed N stress in the spring prior to N fertilization. In
contrast, tall fescue showed no signs of N stress.
Quackgrass Bluebunch Wheatgrass
All entries in this trial established well. They showed lower seedling vigor than tall fescue but were more vigorous than the orchardgrass
varieties. The local selection of quackgrass was the lowest yielding
entry in the trial (Table 3). The highest yielding entry, RS MC87, is a
cross of quackgrass and bluebunch wheatgrass, which may soon be released.
This variety was bred for dryland conditions but yielded well in this
irrigated trial. It has a more upright growth habit than quackgrass and
a more bunch type growth habit similar to bluebunch wheatgrass. The
yield of this variety was roughly equal to the average orchardgrass yield
in an adjacent trial (Tables 2 and 3). Further testing is needed to
confirm the adaptation of these new varieties to Klamath Basin dryland
and irrigated sites; however, it is possible that RS MC87 will be a highyielding variety for irrigated sites that also tolerates dryland conditions.
-
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Table 1. Tall Fescue Variety Trial. Summary of 1989 forage
yields of eight tall fescue varieties established at
the Klamath Experiment Station in the fall of 1988.
Entry
1st Cutting
Yield, lbs/acre
2nd Cutting
3rd Cutting
Total
Fawn
Alta
Kentucky 31
Tandem
Festorina
Johnstone
Forager
Phytor
7306
7420
7694
7314
6800
6911
7520
7888
3379
3494
3893
4721
3626
3386
3860
3437
4064
3725
4511
3441
4003
3982
4140
4096
14750
14640
16100
15480
14430
14280
15520
15420
Mean
CV(%)
LSD(0.05)
7357
11
(NS)
3724
10
573
3995
8
519
15080
8
(NS)
Table 2. Orcbardgrass Variety Trial. Summary of 1989
forage yields of ten orchardgrass varieties
established at the Klamath Experiment Station
in the fall of 1988.
Entry
1st Cutting
Yield, lbs/acre
2nd Cutting
3rd Cutting
Total
Latar
Kara
Rancho
Able
Wana
Potomic
Benchmark
Comet
Orion
Crown
4782
4067
4520
4132
5201
5340
5475
5427
6777
4177
2385
1407
1860
1693
920
1804
2169
2383
5941
1560
4574
3804
3411
2926
2300
3457
4036
4298
3426
3110
11740
9277
9791
8751
8421
10600
11680
12110
16140
8847
Mean
CV(%)
LSD(0.05)
4990
21
1538
2212
19
596
3534
21
1098
10740
13
2076
20
Table 3. Quackgrass Bluebunch Wheatgrass Variety Trial. Summary of 1989
forage yields of two quackgrass-bluebunch wheatgrass crosses
and quackgrass lines established at the Klamath Experiment
Station in the fall of 1988.
-
Entry
1st Cutting
Yield, lbs/acre
2nd Cutting
3rd Cutting
Total
RS MC87'
4689
2347
2699
9734
RS E87 2
4497
1837
1930
8263
RS Hoffman'
4808
1762
2002
8572
Klamath Basin Selection'
3823
1340
1699
6862
Mean
CV(%)
LSD(0.05)
4454
23
NS
1822
9
259
2082
15
512
8358
15
1957
1/ Elytrigia repens (quackgrass) x Pseudoroegeria spicata (native bluebunch
wheatgrass) hybrid.
2/ E. repens x P. stipifolia (Asian bluebunch wheatgrass) hybrid.
3/ E. repens selection introduced from Turkey.
4/ E. repens selection from the Jack Liskey Ranch.