Alfalfa Variety Performance at Tucson, 2005-2006
M. J. Ottman and S. E. Smith
Introduction
New alfalfa varieties are constantly being introduced into the marketplace. The
number of varieties available for low-elevation desert areas in Arizona in the
non-dormant and very non-dormant class is close to 50. New varieties are
introduced each year and unbiased yield comparisons are helpful to the grower
to base the decision of whether or not to sow a new variety. The study reported
here is part of the on-going effort to evaluate alfalfa variety performance in
Arizona. A summary of small grain variety trials conducted by the University of
Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1267.pdf.
Procedure
Alfalfa varieties and experimentals (potential varieties being evaluated for future release) were compared in a field
study at the Campus Agricultural Center in Tucson, Arizona. The experimental design was a randomized complete
block with four replications and 12 entries. Seed was sown on November 5, 2004 into five rows spaced 6 inches
apart with a single row hand planter at a rate of 20 pounds of seed per acre. The plots were 3 ft. wide by 12 ft. long.
Irrigation water was applied the same day as planting to germinate the seed. Irrigations of about 4 to 6 inches each
were applied using the border flood method at an interval of twice per cutting. The plots were cut with a sickle-bar
mower, the forage was raked, placed on a tarp, and weighed. The cutting interval at the peak of the season was 4
weeks. The plots were subjected to insect pressure from Egyptian alfalfa weevil, various aphids, alfalfa caterpillar,
and beet armyworm, but damage from these pests was not severe enough to warrant chemical control. No
herbicides or fertilizers were applied. Plant stand was estimated by counting crowns from two 4 ft2 areas in each
plot on 12 Dec 06. The data was analyzed using nearest neighbor analysis and least-squares means are reported.
Least-squares means were calculated for the annual totals and are not identical to the sum of the least-squares means
of the individual harvests. Hay yield was calculated by assuming 80% moisture in the forage, and calculating hay
yield on a 12% moisture basis for the plot area.
Discussion
Hay yields for the varieties tested are presented in Table 1. No general conclusions will be made from this study,
which is part of an ongoing effort to evaluate alfalfa variety performance in Arizona. This information is intended
to help growers decide whether or not to plant a new variety on a limited acreage on commercial farms. A new
variety should be planted on a larger acreage only after the variety has been evaluated on a smaller acreage under
farm-specific conditions.
Acknowledgments
This research trial was supported by Barkley Seed, Cal-West Seeds, S&W Seeds, and ABI Alfalfa.
Forage and Grain Report (P-154) October 2007
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Table 1. Hay yield adjusted to 12% moisture for alfalfa varieties and experimentals at Tucson, AZ in 2005.
Hay Yield
2005
Variety
4/26
5/24
6/24
7/20
8/19
9/15
11/3
Total
----------------------------------------------------- tons/acre ----------------------------------------------------SW 9434
SW 9332
SW 9215
Grassroots
Lew
ZS 0301
CUF 101
CW 99053
CW 09051
DS399
ZS 0400
Magna 901
1.79
1.67
1.79
1.94
1.73
1.82
1.70
1.85
1.82
1.71
1.85
1.55
2.38
2.44
2.50
2.58
2.25
2.41
2.36
2.53
2.51
2.46
2.39
2.27
2.92
3.10
2.87
2.79
2.78
2.93
2.91
2.89
2.72
2.59
2.73
2.60
1.70
1.90
1.63
1.39
1.58
1.63
1.58
1.63
1.55
1.47
1.62
1.43
1.89
1.97
1.91
1.82
1.80
1.84
1.82
1.81
1.73
1.70
1.68
1.59
1.37
1.34
1.28
1.26
1.26
1.21
1.26
1.25
1.16
1.14
1.16
1.14
1.96
1.89
1.73
1.82
1.81
1.86
1.82
1.68
1.67
1.66
1.77
1.68
14.07
14.23
13.84
13.62
13.25
13.73
13.45
13.61
13.16
12.72
13.11
12.18
Average
CV (%)
LSD (5%)
1.77
6.44
0.16
2.42
3.83
0.13
2.82
7.07
0.29
1.59
12.44
0.28
1.80
5.26
0.14
1.23
6.11
0.10
1.78
6.18
0.15
13.41
4.41
0.85
Table 1 (Con’d). Hay yield adjusted to 12% moisture for alfalfa varieties and experimentals at Tucson, AZ in 2006,
total yield for 2005 and 2006, and final stand on 7 Dec 06.
Hay Yield
Stand
2006
2005-06 2006
Variety
3/24
5/5
5/30
6/27
7/24
8/31
10/5 11/21 Total Total
12/7
---------------------------------------------- tons/acre ---------------------------------------------- crowns/ft2
SW 9434
SW 9332
SW 9215
Grassroots
Lew
ZS 0301
CUF 101
CW 99053
CW 09051
DS399
ZS 0400
Magna 901
2.58
2.74
2.49
2.92
2.72
2.79
2.71
2.64
2.59
2.53
2.59
2.55
2.52
2.60
2.51
2.51
2.63
2.47
2.46
2.40
2.47
2.37
2.24
2.30
2.26
2.22
2.18
2.15
2.18
2.01
2.08
2.07
2.03
2.09
1.95
2.10
2.34
2.34
2.27
2.23
2.15
2.14
2.18
2.15
2.11
2.06
1.98
2.07
1.83
1.81
1.76
1.66
1.60
1.59
1.68
1.62
1.57
1.56
1.45
1.54
2.00
1.88
1.99
1.85
1.94
1.74
1.74
1.79
1.81
1.70
1.68
1.69
1.20
1.18
1.17
1.08
1.17
1.10
1.09
0.98
1.03
1.03
0.88
0.98
1.80
1.71
1.64
1.66
1.64
1.66
1.61
1.52
1.44
1.42
1.51
1.50
16.64
16.23
16.26
16.14
16.11
15.64
15.51
15.09
15.07
14.80
13.86
14.64
30.74
30.58
29.98
29.76
29.32
29.25
29.06
28.64
28.25
27.46
27.11
26.87
4.31
5.06
5.06
5.06
3.94
4.28
4.44
4.59
4.44
3.91
4.59
3.50
Average
CV (%)
LSD (5%)
2.65
5.02
0.19
2.46
6.15
0.21
2.11
6.86
0.20
2.17
6.70
0.20
1.64
5.71
0.13
1.82
7.18
0.19
1.07
8.61
0.13
1.59
7.18
0.16
15.50
4.77
1.07
28.92
3.70
1.52
4.43
8.71
0.55
Forage and Grain Report (P-154) October 2007
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