Alfalfa Variety Performance at Tucson, 2009-2010 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 class is over50. 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 ongoing effort to evaluate alfalfa variety performance in Arizona. A summary of alfalfa 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 2 October, 2008 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 19 Dec 2010. 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 Cal/West Seeds, Dairyland Seed Co., Inc., Forage Genetics, S. & W. Seeds. 2012 Forage & Grain Report, College of Agriculture and Life Sciences, University of Arizona 4 Table 1. Hay yield adjusted to 12% moisture for alfalfa varieties and experimentals at Tucson, AZ in 2009. Entry Hay Yield 2009 4/10 5/5 6/16 7/14 8/11 9/10 10/8 12/15 Total ------------------------------------------ tons/acre ------------------------------------------ A-1086 AL 999 CUF 101 CW 1010 DS067092 DS077601 DS593 Fertilac 10 FG 105+285 FG 105+286 FG 106+701 FG 115+288 FG 92+206 Lew Magna 995 Mecca III SW 9628 SW 9803 SW 9812 SW 9813 SW 9816 TS 0002 WL 625 HQ 1.29 1.18 1.26 1.27 1.21 1.33 1.17 1.35 1.31 1.34 1.19 1.24 1.26 1.40 1.12 1.37 1.26 1.27 1.25 1.25 1.33 1.36 1.16 1.17 1.07 1.12 1.18 1.15 1.18 1.19 1.17 1.08 1.15 1.04 1.08 1.13 1.10 1.09 1.16 1.18 1.18 1.11 1.09 1.20 1.16 1.06 1.58 1.50 1.52 1.65 1.61 1.67 1.68 1.65 1.57 1.64 1.62 1.60 1.66 1.49 1.58 1.71 1.68 1.64 1.64 1.60 1.64 1.57 1.62 2.72 2.63 2.53 2.67 2.63 2.68 2.52 2.76 2.65 2.74 2.70 2.65 2.64 2.60 2.79 2.59 2.68 2.52 2.69 2.60 2.70 2.65 2.82 2.06 1.97 1.96 2.03 1.98 2.03 1.95 2.06 2.07 2.09 2.09 2.07 2.03 1.99 2.11 2.01 2.14 2.03 2.05 2.09 2.06 2.01 2.05 2.16 2.19 2.10 2.38 2.39 2.40 2.27 2.27 2.26 2.31 2.36 2.28 2.18 2.29 2.26 2.35 2.32 2.35 2.32 2.29 2.28 2.27 2.31 1.89 1.93 1.89 1.98 1.91 2.02 1.89 2.00 2.00 1.95 2.10 2.02 1.92 1.99 1.94 1.99 2.03 2.08 2.03 1.95 2.03 1.91 1.87 2.03 2.04 1.97 2.08 1.95 2.00 2.04 2.19 2.13 2.21 1.97 2.13 2.05 2.14 1.91 1.99 2.09 2.17 2.07 2.14 2.18 2.21 2.00 14.9 14.4 14.3 15.1 14.7 15.1 14.8 15.3 14.9 15.4 14.9 15.1 14.9 15.0 14.6 15.1 15.2 15.0 15.1 14.9 15.2 15.1 14.8 CV (%) LSD (5%) 8.48 0.147 9.37 0.106 7.00 0.116 4.33 0.162 5.19 0.145 4.44 0.148 3.68 0.103 7.02 0.200 2.62 0.54 2012 Forage & Grain Report, College of Agriculture and Life Sciences, University of Arizona 5 Table 1 (Con’d). Hay yield adjusted to 12% moisture for alfalfa varieties and experimentals at Tucson, AZ in 20108, total yield for 2009 and 2010, and final stand on 16 Dec 2010. Entry Hay Yield 2010 2009-10 3/25 5/13 7/15 8/12 9/9 10/28 12/16 Total Total ------------------------------------------ tons/acre ------------------------------------------ Stand 2010 12/19 plants/ft2 A-1086 AL 999 CUF 101 CW 1010 DS067092 DS077601 DS593 Fertilac 10 FG 105+285 FG 105+286 FG 106+701 FG 115+288 FG 92+206 Lew Magna 995 Mecca III SW 9628 SW 9803 SW 9812 SW 9813 SW 9816 TS 0002 WL 625 HQ 2.71 2.60 2.48 2.65 2.61 2.68 2.56 2.76 2.64 2.74 2.65 2.65 2.64 2.61 2.77 2.57 2.69 2.50 2.69 2.61 2.69 2.66 2.80 2.71 2.64 2.70 2.67 2.73 2.85 2.96 3.00 2.80 2.94 2.73 2.80 2.69 2.81 2.62 2.88 2.87 2.72 2.77 2.90 2.77 2.99 2.82 2.06 2.21 2.26 2.09 2.15 2.15 2.15 2.14 2.32 2.33 2.47 2.38 2.39 2.10 2.15 2.19 2.19 2.11 2.24 2.12 2.18 2.14 2.22 1.94 2.02 2.00 1.91 1.91 2.01 1.95 1.89 2.16 2.06 2.01 2.04 2.11 1.97 1.98 1.91 2.02 1.89 2.02 1.92 2.00 1.89 2.04 1.79 1.85 1.84 1.87 1.76 1.81 1.70 1.77 1.90 1.93 1.89 1.89 1.88 1.84 1.83 1.76 1.85 1.77 1.83 1.80 1.82 1.71 1.85 1.81 1.83 1.77 1.92 1.71 1.89 1.73 1.89 1.79 1.82 1.82 1.77 1.89 1.88 1.84 1.79 1.80 1.83 1.80 1.94 1.94 1.85 1.84 1.36 1.35 1.36 1.35 1.24 1.30 1.30 1.37 1.45 1.46 1.43 1.45 1.40 1.37 1.32 1.37 1.39 1.38 1.32 1.40 1.40 1.38 1.39 14.5 14.6 14.1 14.7 14.2 14.4 14.5 14.9 14.7 15.2 15.1 15.1 15.2 14.4 14.7 14.5 15.0 14.1 14.7 14.6 14.9 14.4 15.0 29.3 28.9 28.4 29.7 28.9 29.6 29.3 30.2 29.6 30.6 30.0 30.3 30.1 29.4 29.2 29.5 30.2 29.0 29.8 29.4 30.1 29.6 29.8 3.63 4.00 4.19 4.19 4.34 4.13 4.00 4.41 4.22 4.28 4.34 3.63 4.59 4.34 4.47 4.00 3.97 4.19 3.97 3.63 4.03 3.91 4.28 CV (%) LSD (5%) 4.53 0.167 7.38 0.290 6.17 0.191 5.61 0.157 4.78 0.122 5.49 0.141 5.04 0.097 3.52 0.73 2.70 1.11 10.66 0.62 2012 Forage & Grain Report, College of Agriculture and Life Sciences, University of Arizona 6