109
Alfalfa Variety Trial
R.L. Dovel and J. Rainey l
INTRODUCTION
Alfalfa is a major forage commodity in the Klamath Basin. It is grown on over
40,000 acres in Klamath County alone. Major markets for Klamath Basin alfalfa are
dairies, cattle ranches, and horse farms in Oregon and California. Premium quality hay
suitable for the dairy hay market, requires timely cutting, good weed control, and an
adequate stand. Little difference in forage quality has been seen between alfalfa
varieties in the past. Breeding programs are striving to improve alfalfa quality. Varieties
reportedly superior in quality are beginning to be marketed; however, management still
appears to have more effect on forage quality than varietal differences.
Few pests attack alfalfa in the Klamath Basin. The main diseases present are
bacterial wilt and phytophthora root rot. Verticillium wilt has not been found in the
basin, but it occurs in many surrounding areas. The main insect pest is the alfalfa
weavil. Some breeding programs are beginning to select for resistance to this pest. Rest
resistances are important variety selection criteria.
Winter hardiness is important in selecting a variety for the Klamath Basin. Winter
hardiness has been closely linked with fall dormancy ratings; however, less dormant
varieties have experienced reasonable stand longevity in recent years, perhaps due to
relatively mild winters. Local variety trials are being used to develop empirical winter
hardiness and stand persistence measurements to supplement fall dormancy ratings as a
measure of variety hardiness.
Forage yield is a function of a complex set of interactions between the alfalfa plant
and its environment. Variety trials conducted at the KES provide alfalfa producers
locally developed data on the yield potential and persistence of new alfalfa varieties.
One trial, established in 1986, was monitored for yield during the period from 1987-1990;
was maintained as a commercial field in 1991 and 1992; and will be evaluated for stand
persistence and yield in 1993. A trial established in 1991 is the main subject of this
report.
1
/ Assistant Professor and Biological Sciences Research Technician, respectively,
Klamath Experiment Station, Klamath Falls, OR.
Acknowledgments: Financial support of these studies from the following companies is
appreciated: Allied Seed; DeKalb Seed; North American Plant Breeders; Northrup King
Co.; Pioneer Hi-Bred International; Plant Genetics; Union Seed Co.; and W-L Research.
110
PROCEDURES
A trial including 48 released and experimental alfalfa varieties was established in
May, 1991. Varieties were arranged in a randomized complete block design with four
replications. Soil samples from the field were analyzed and the appropriate fertilizer
applied prior to planting. A tank mix of EPTC and Benefin was applied prior to
planting at 3 and 1.2 lb ai/A, respectively Immediately after application, herbicides
were incorporated with a rototiller. Seed was drilled to a depth of 1/4 inch at a rate of
20 lb/A using a modified Kincaid drill. Plots were 5 x 30 feet with 5-foot borders and
alleyways. The crop was sprinkler irrigated with a solid set system.
Plants were allowed to grow through the first growing season with only a fall
cutting. Alfalfa was harvested in 1992 when plants reached early bud stage. Unusually
warm spring weather allowed four cuttings, one more than is normally obtained in trials
at KES. The crop was harvested using a flail harvester with a three-foot wide head. All
yields are reported on a dry weight basis.
RESULTS AND DISCUSSION
Over the first two years, most of the varieties produced similar yields. About 35
percent of the varieties were significantly higher in total yield than the standard variety,
Vernal (Table 1). None of the varieties were significantly lower than Vernal. The
selection of an appropriate variety should be based on pest resistance and winter
hardiness as well as yield. The collection of only one full year of data is inadequate to
provide an estimate of the relative yield potential of the varieties in the trial. An
additional two years of data are needed to adequately assess yield potential, and
preferably longer, to evaluate stand survival of these varieties.
Another 48 entry alfalfa variety trial was established at KES in 1986 and yield data
was collected from 1987-1990. A four-year summary of that trial has been published in
the 1990 station annual report. Sixteen of the varieties in the 1991 trial were also in the
trial established in 1986. Of that group, WL 225, Arrow, Excalibur, and Vector averaged
6.4 tons dry matter (DM)/A over a four-year period. This was a significantly higher
yield than Vernal. Six other entries were not significantly different than the four top
yielding varieties. They were Max 85 brand, WS 320, Apollo II, Sparta, Centurion, and
DK 120. Harvest of this trial was suspended in 1990; however, the trial was maintained
and harvested as a hay field. These plots will be harvested as a variety trial in 1993 to
evaluate the long term persistence of varieties.
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Table 1. Alfalfa Variety Trial. Forage yields of 48 alfalfa varieties planted at the Klamath
Experiment Station in 1991.
Entry
No. Variety
1991
Cut 1
Cut 1
Cut 2
1992
Cut 3
Cut 4
1992
Total
2 Year
Total
lb/A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
'19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
DK 122
DK 120
DK 135
DK 125
Asset (VS 655)
Centurion
Multistar
Majestic (NY 86142)
Sabre (NY 86141)
Webfoot
MS 90
UN-74
Legend
Apollo Supreme
Arrow
Aggressor
Archer
Husky
GS-88
Ultra
Expt. 91-01
Max 85
87-201
WL-317
WL-320
WL-225
WL-316
Sparta
Champ
Fortress
Multileaf II
Excaliber
Blazer
Belmont
Cimmaron VR
Columbo
9047 IV
Millanaker1.1
Flint
PB 5364
SCO 0042
SCO 0043
Rancher Special
Appollo II
Atra 55
Vector
LM 331
2690
2200
2390
3040
2410
2280
2360
2130
2120
2240
2420
2570
2620
2260
2600
2050
2240
1960
2330
2680
1950
2820
2720
1940
2340
2870
2560
2040
2350
2110
2480
2450
2490
2650
2280
2720
2650
2490
2560
2520
2520
2060
1920
2300
2520
1730
2340
2280
7060
7750
6300
6270
7230
6290
7620
5760
6510
6640
6410
7250
6990
6470
6400
6620
6900
5980
6050
6850
5590
6500
6630
6020
5970
6230
5790
6230
6330
5710
6630
6980
7480
6460
5630
6040
6270
7290
6860
6460
6760
4880
4140
7210
6280
7970
6330
6190
4350
4500
4300
4210
4180
4290
3880
4250
4220
3900
4450
4160
4220
4240
4180
3970
4360
4370
4140
4390
2970
4400
4010
4010
4280
4450
4100
4310
4120
4390
4450
3970
4180
4350
4290
4110
4360
4040
4010
3940
4030
3580
3560
4400
4410
4650
4150
4030
2900
2850
3000
2810
3030
3250
2780
3070
2880
2900
3100
2890
2980
3090
2900
2870
3150
2910
2820
3090
3200
2640
2950
2710
3000
2810
3100
2660
2930
3040
3010
3120
3070
3310
3240
3170
2900
2720
2840
2920
2910
3310
2960
2790
2980
3010
2870
3110
1190
1140
1160
1130
1420
1260
1170
1110
1110
950
1260
1260
1310
1110
1170
1350
1760
1080
1340
1050
1700
1280
1690
1070
1460
930
1460
660
1190
1220
1310
1200
1320
1410
1360
1440
1310
1040
1040
1240
1130
1670
1730
1160
1190
1390
1310
1430
15500
16240
14760
14430
15850
15090
15440
14190
14720
14370
15220
15560
15510
14900
14650
14800
16170
14340
14330
15380
13450
14820
15280
13810
14720
14420
14450
13850
14570
14360
15390
15270
16050
15530
14520
14760
14840
15080
14750
14570
14830
13440
12390
15570
14850
17020
14670
14760
18180
18440
17140
17470
18270
17360
17800
16310
16840
16620
17640
18130
18130
17170
17240
16860
18400
16300
16670
18060
15400
17640
17990
15750
17060
17290
17010
15890
16920
16460
17870
17720
18530
18190
16800
17480
17500
17570
17310
16980
17350
15500
14320
17870
17370
18750
17010
17040
Mean
CV (%)
Lav0.05)
2380
16
530
6460
17
1570
4190
10
560
2970
9
390
1260
16
280
14870
9
1780
17260
8
1870
Vernal
.