Fourth Year Results of the 1999 to 2003 Alfalfa Forage Variety Trial

Eric P. Eldredge, Clinton C. Shock, and Lamont D. Saunders

Malheur Experiment Station

Oregon State University

Ontario, OR, 2002

Introduction

Increasing dairy herds in Oregon and Idaho, and increasing exports of alfalfa cubes, compressed bales, and pellets to nations across the Pacific, create a marketing opportunity for premium quality hay. Quality hay can be obtained by cutting alfalfa early, when buds are fully formed, but before the first flowers open. Total yield will be lower than it could be with later cuttings. However, when there is strong demand for premium quality hay, the increased market value may more than compensate for lower yield.

Producing premium quality hay involves increased risk. Repeated early cutting reduces stored carbohydrate in the roots, and can result in thinning stands or a shorter life of the stand. Alfalfa stressed by repeated early cutting is more susceptible to pests and diseases that may be present in the field. Varieties can vary in their ability to withstand frequent cutting, diseases, and insects.

In this 5-year trial, 12 proprietary varieties are being compared to 2 public check varieties for production of high quality hay. The purpose of this trial is to identify alfalfa varieties that can remain productive when cut early for high quality hay. The trial was established on marginally productive soil with sprinkler irrigation, characteristic of the soil and irrigation often used for alfalfa hay production.

Methods

The trial was established in September 1998, on Nyssa silt loam that had not been deep plowed. Details of this trial's establishment are in a previous annual report (Eldredge et al. 2000), which is also posted on the Internet here.

Plots were 20 ft long by 5 ft wide, separated at their ends by 3-ft alleys, with each variety replicated five times in a randomized complete block design. Fall regrowth was mowed with a flail mower and removed from the field on November 14, 2002 to reduce soil cover and improve herbicide spray penetration and effectiveness. Soil cover during winter can also promote rodent colonization of the alfalfa stand.

The alfalfa was harvested on May 28, June 25, July 24, and September 9, 2002. The first three cuttings were at bud stage. The fourth cutting was in early bloom because rainy weather delayed the fourth cutting. At each cutting date, a 3-ft by 20-ft swath was cut from the center of each plot using a flail mower, and the alfalfa was weighed. Ten random samples of alfalfa were collected over the entire field before each cutting, dried in a forage drier at 140°F with forced air, and reweighed to determine the moisture content at each cutting. Yield was reported based on alfalfa hay at 88 percent dry matter.

Samples of approximately 20 stems per plot were taken on June 25, just before the second cutting, to measure forage quality. The forage quality samples were dried, ground to pass a 1-mm screen, sub-sampled, and sent to the OSU Forage Quality Lab at Klamath Falls, Oregon, where they were reground to pass a 0.5-mm screen. Near infrared spectroscopy (NIRS) was used to estimate percent crude protein, percent acid detergent fiber (ADF), and percent neutral detergent fiber (NDF). Relative feed value (RFV) was calculated by the formula:

RFV = {[88.9 - (ADF * 0.779)] * (120/NDF)}/1.29

Quality standards based on RFV are: prime, RFV higher than 151; No. 1, RFV 151-125; No. 2, RFV 124-103; No. 3, RFV 102-87; No. 4, RFV 86-75; and No. 5, RFV less than 75 (Undersander et al. 1991). Hay with a higher RFV requires less grain or feed concentrate to formulate the dairy ration.

Results and Discussion

The average fourth year total hay yield was 6.38 ton/acre (Table 1). There were no significant differences in hay yield between varieties in any cuttings.

The crude protein, which averaged 26.2 percent in the second cutting, ranged from 25.1 percent for 'Lahontan' to 27.2 percent for 'W-L 325 HQ'. Acid detergent fiber averaged 27.8 percent; NDF averaged 39.1 percent. All varieties produced prime quality hay in the second cutting, with RFV higher than 151.

Over the 4 years, hay yield averaged 5.91 ton/acre/year (Table 2). Hay yields were higher in 2002 than in 1999 or 2001. Information on the disease, nematode, and insect resistance of the varieties in this trial was provided by the participating seed companies and/or the North American Alfalfa Improvement Council (Table 3). Most alfalfa varieties have some resistance to diseases and pests that could limit hay production in our area. Growers should choose varieties that have stronger resistance ratings for disease or pest problems known to be present in their fields. The yield potential of a variety should be evaluated based on performance in replicated trials at multiple sites over multiple years.

References

Eldredge, E. P., C.C. Shock, and L. D. Saunders. 2000. First year yield of the 1999-2003 alfalfa forage variety trial. Oregon State University Agricultural Experiment Station, Special Report 1015:12-15.

Undersander, D., N. Martin, D. Cosgrove, K. Kelling, M. Schmitt, R. Becker, C. Grau, and J. Doll. 1991. Alfalfa management guide. ASA-CSSA-SSSA, Madison, WI.

Table 1. Alfalfa variety hay yields and second cutting crude protein*, ADF*, NDF*, and RFV for 2002. Malheur Experiment Station, Oregon State University, Ontario, OR.


Cutting date 2002 Crude

Relative

Variety

5/28 6/25 7/24 9/24 total protein ADF NDF feed value

----------------ton/acre§------------------- ------- % of DW -------- RFV

W-L 325 HQ

2.26 1.88 1.46 1.48 7.08 27.2 26.4 38.0 167

Surpass

2.32 1.72 1.38 1.42 6.84 26.3 27.6 38.7 162

Tango

2.14 1.80 1.28 1.42 6.62 25.7 28.6 39.8 156

DK 142

2.24 1.60 1.28 1.40 6.52 26.6 27.1 38.5 164

Emperor

2.24 1.58 1.36 1.34 6.46 26.4 27.3 38.7 163

Archer II

2.02 1.76 1.26 1.36 6.38 26.0 27.8 39.2 160

ZX9453

2.12 1.68 1.32 1.28 6.38 25.6 29.1 40.1 154

Gold Plus

2.12 1.62 1.32 1.30 6.34 26.2 28.4 39.6 157

Rambo

2.02 1.66 1.34 1.32 6.32 26.9 27.2 38.8 163

G9722

2.04 1.56 1.42 1.28 6.30 26.2 27.6 39.0 161

Wrangler

2.04 1.56 1.26 1.42 6.26 26.0 28.0 39.5 158

Plumas

2.02 1.60 1.28 1.34 6.24 26.3 27.6 38.9 161

Multi-5301

1.82 1.44 1.30 1.32 5.86 26.2 27.7 38.8 161

Lahontan

1.68 1.52 1.28 1.20 5.68 25.1 28.7 39.5 157
Mean 2.08 1.64 1.32 1.35 6.38 26.2 27.8 39.1 160
LSD(0.05) NS†† NS NS NS NS 1.0 NS NS NS
Table 2. Forage yield of alfalfa varieties over four production years. Malheur Experiment Station, Oregon State University, Ontario, OR 2002.





Four year

Variety

1999 2000 2001 2002 Total Average

--------------------------------ton/acre*--------------------------------

Rambo

4.22 7.41 6.28 6.84 24.75 6.19

Surpass

3.68 7.43 6.35 7.08 24.54 6.14

Emperor

4.55 7.60 5.76 6.46 24.37 6.09

ZX9453

3.83 7.68 6.19 6.62 24.32 6.08

Archer II

4.62 7.52 5.81 6.32 24.27 6.07

Tango

4.42 7.61 5.76 6.38 24.17 6.04

G9722

4.57 7.54 5.63 6.38 24.12 6.03

W-L 325 HQ

4.36 7.82 5.37 6.30 23.85 5.96

DK 142

4.25 7.32 5.66 6.52 23.75 5.94

Plumas

3.85 7.29 5.66 6.34 23.14 5.79

Gold Plus

3.75 7.71 5.42 6.24 23.12 5.78

Wrangler

4.37 6.86 5.53 6.26 23.02 5.76

Multi-5301

3.99 7.52 4.79 5.86 22.16 5.54

Lahontan

4.20 6.17 5.25 5.68 21.30 5.33

Mean

4.19 7.39 5.68 6.38 23.64 5.91

LSD (0.05)

NS 0.67 NS NS NS NS

*Yield at 88 percent dry matter.

Table 3. Variety source, year of release, fall dormancy, and level of resistance to pests and diseases for 14 varieties in the 1999-2003 forage variety trial. Malheur Experiment Station, Oregon State University, Ontario, OR 2002.



Release
Pest Resistance rating

Variety

Source

year FD BW FW VW PRR AN SAA PA SN AP RKN
Lahontan public 1954 6§

MR

LR

-

LR

-

MR

LR

R

-

-

Wrangler

public

1984 2

R

R

LR

HR

LR

HR

HR

-

-

-

Surpass

Andrews Seed

1985 3

HR

HR

R

R

MR

-

R

-

-

-

Rambo

ABI Alfalfa

1995 3

HR

HR

R

HR

HR

MR

R

R

R

-

DK 142

DeKalb

1996 4

HR

HR

R

HR

R

R

HR

R

HR

-

Tango

Eureka Seeds

1997 6

MR

HR

HR

HR

HR

HR

HR

MR

-

R

WL 325 HQ

W-L Research

1997 3

HR

HR

R

HR

HR

R

R

R

R

-

Archer II

ABI Alfalfa

1998 5

R

HR

HR

R

HR

R

MR

R

LR

R

Emperor

ABI Alfalfa

1998 4

HR

HR

HR

HR

HR

MR

R

-

HR

-

Gold Plus

MBS Inc.

1998 4

HR

HR

R

HR

HR

HR

HR

HR

R

-

Multi-5301

Geertson Seed

1998 4

R

HR

R

MR

HR

-

R

-

R

-

Plumas

Eureka Seeds

1998 4

R

HR

R

HR

HR

HR

R

HR

R

MR

ZX9453

ABI Alfalfa

- 5

-

HR

R

R

MR

R

R

HR

-

MR

G9722

Geertson Seed

- 6

R

R

-

R

-

R

HR

-

-

-

FD: fall dormancy, BW: bacterial Wilt, FW: Fusarium wilt, VW: Verticillium wilt, PRR: Phytophthora root rot, AN: Anthracnose, SAA: spotted alfalfa aphid, PA: pea aphid, SN: stem nematode, AP: Aphanomyces, RKN: root knot nematode (Northern).

Pest Resistance Rating: >50% = HR (high resistance), 31-50% = R (resistant), 15-30% = MR (moderate resistance), 6-14% = LR (low resistance) .

§Fall Dormancy: 1 = Norseman, 2 = Vernal, 3 = Ranger, 4 = Saranac, 5 = DuPuits, 6 = Lahontan, 7 = Mesilla, 8 = Moapa 69, 9 = CUF 101.