Third-Year Results of the 2006 to 2011 Furrow-irrigated Alfalfa Forage Variety Trial

Clinton C. Shock and Lamont D. Saunders

Malheur Experiment Station

Oregon State University

Ontario, OR, 2008

Introduction

The purpose of this trial is to compare the productivity and hay quality of alfalfa varieties in the Treasure Valley area of Malheur County. The trial also provides information about the adaptation of alfalfa varieties to furrow irrigation for hay production. In this

5-year trial, 7 proprietary varieties and 1 seed treatment are being compared to 2 public check varieties.

Methods

The trial was established on Owyhee silt loam where winter wheat was the previous crop and alfalfa had not been grown for more than 10 years. Details of crop establishment are in last year's annual report, which is available at http://www.cropinfo.net/AnnualReports/2006/06AlfAnnReport.html. Seed of each proprietary entry was supplied by the company, and certified seed of the two public check varieties was obtained locally. The entry 'FC2055' was the same variety as 'FC1055' except FC2055 included a proprietary seed treatment. This trial was established and grown with furrow irrigation from gated pipe, with furrows spaced 30 inches apart.

In 2008, the first cutting was taken on June 10. A 32-inch by 20-ft swath was cut from the center of each plot with a flail mower, and the alfalfa was weighed. The alfalfa was harvested twice more, on July 15 and August 19. Ten samples of alfalfa were cut by hand from the edges of plots over the entire field at random on the same day just before each harvest. The samples were quickly weighed, then dried at 140°F for 48 hours, and reweighed to determine the average alfalfa moisture content at each cutting. Yield was reported as tons/acre of alfalfa hay at 88 percent dry matter.

Samples of alfalfa to measure forage quality were taken mid-morning before the third cutting from approximately 1 ft of row per plot. The forage quality samples were dried at 140°F for 48 hours, ground in a Wiley mill (Thomas Scientific, Swedesboro, NJ) to pass through a 1-mm screen, and sent to the Oregon State University Forage Quality Lab at Klamath Falls, Oregon, where they were reground in a UDY mill (UDY Corp., Ft. Collins, CO) to pass through a 0.5-mm screen. Near infrared spectroscopy (NIRS) was used to estimate percent dry matter, percent crude protein, percent acid detergent fiber (ADF), percent neutral detergent fiber (NDF), percent fat, and percent ash.

Relationships for estimated dry matter intake for alfalfa hay (DMI), total digestible nutrients for alfalfa hay (TDNL), and relative forage quality (RFQ) were calculated using empirical formulas.

DMI, the dry matter intake (for alfalfa hay) was estimated by the equation

DMI = ((((0.120 * 1350) / (NDF/100)) + (NDFD - 45) * 0.374)) / 1350 * 100,

where NDFD = dNDF48 / NDF * 100 and dNDF48 is the digestible NDF as a percentage of dry matter, as determined by a 48-hour in vitro digestion test.

TDNL, the total digestible nutrients for alfalfa hay, was estimated by the equation

TDNL = (NFC * 0.98) + (Protein * 0.93) + (Fat * 0.97 * 2.25) + ((NDF-2) * (NDFD/100)) where NFC = 100 - ((NDF - 2) + Protein + 2.5 + Ash).

Relative forage quality was calculated by the formula:

RFQ = (DMI * TDNL) / 1.23

where: 1.23 is used as the denominator to adjust the scale to match the relative forage value (RFV) scale at 100 = full bloom alfalfa.

Quality standards for alfalfa hay based on RFQ are: Supreme, RFQ higher than 185; Premium, RFQ 170-184; Good, RFQ 150-169; Fair, RFQ 130-149, and Low, RFQ below 129. Relative forage quality is an estimate of voluntary energy intake when the alfalfa hay is the only source of energy and protein for ruminants. The higher the RFQ, the less grain or feed concentrate supplements are required to formulate dairy rations.

Results and Discussion

Weather in 2008 was cool and dry, which slowed the alfalfa growth. Most of the varieties were in the late bud to early bloom stage when the first cutting was taken. The second cutting was taken July 15 at mid-bud stage. Third cutting, when forage quality samples were taken, was on August 19, at late-bud stage.

Crude protein in 2008 averaged 23.5 percent in the third cutting, and ranged from 24.2 percent for 'DKA-42-15' to 22.2 percent for 'Lahontan'. Acid detergent fiber averaged 32.1 percent, and ranged from 33.2 percent for Lahontan to 30.4 percent for DKA-42-15. Neutral detergent fiber averaged 36.7 percent, and ranged from 38.2 percent for 'FC 1045' to 34.8 percent for 'WL 319 HQ'. Relative forage quality averaged 191, in the "Supreme" quality category, and ranged from RFQ = 203 "Supreme" for DKA-42-15 to RFQ = 178 "Good" for Lahontan.

After 3 years, among the highest yielding varieties were 'Masterpiece', 'WL 357 HQ', DKA-42-15, FC 2055, WL 319 HQ, and 'Rustler II', which produced over 21 ton/acre cumulative total hay yield for 2006 and 2007 (Table 2).

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 the diseases and pests that could limit hay production. Growers should choose varieties with 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.

Table 1. Alfalfa variety hay yielda in 2008 and third cutting crude protein, ADF, NDF, and RFQ for 2008. Malheur Experiment Station, Oregon State University, Ontario, OR.

Date

2008

Crude

Variety

6/10

7/15

8/19

total

protein

ADFb

NDFc

RFQd

-------% of DWe-------

Lahontan

2.58

1.75

1.81

6.13

23.4

32.4

37.4

185.0

Wrangler

2.88

1.67

1.71

6.27

23.8

31.6

36.2

196.8

DKA-42-15

2.91

1.89

1.82

6.61

24.0

30.8

34.8

202.0

FC 1045

2.84

1.77

1.66

6.26

23.6

32.8

37.2

187.4

FC 1055

2.74

1.82

1.89

6.45

24.2

30.4

35.0

202.6

FC 2055

2.90

1.97

1.84

6.70

23.4

33.0

38.2

182.2

Rustler II

2.81

1.85

1.86

6.53

23.6

32.2

36.4

192.2

Masterpiece

2.91

1.86

1.76

6.54

23.2

32.8

37.2

189.6

WL 319 HQ

2.79

1.84

1.67

6.30

23.6

32.2

36.4

194.8

WL 357 HQ

2.62

1.94

1.85

6.41

22.2

33.2

38.0

177.8

Mean

2.80

1.83

1.79

6.42

23.5

32.1

36.7

191.0

LSD (0.05)

0.34

NSf

NSf

NSf

NSf

1.44

1.64

13.39














aYield at 88% dry matter. bADF: acid detergent fiber. cNDF: neutral detergent fiber.

dRFQ: relative forage quality. eDW: dry weight. fNS: not significant at the alpha = 0.05 level.


Table 2. Alfalfa variety hay yield in the first 3 years and cumulative total yield in the 2006-2011 furrow-irrigated forage variety trial. Malheur Experiment Station, Oregon State University, Ontario, OR, 2008.

2006

2007

2008

Cumulative

Variety

total

total

total

total



------------------------- ton/acrea -------------------------

Lahontan

6.80

7.12

6.13

20.05

Wrangler

6.51

7.32

6.27

20.10

DKA-42-15

7.08

7.83

6.61

21.51

FC 1045

6.85

7.64

6.26

20.76

FC 1055

6.72

7.60

6.45

20.76

FC 2055

6.92

7.92

6.70

21.55

Rustler II

7.07

7.60

6.53

21.19

Masterpiece

7.04

8.03

6.54

21.61

WL 319 HQ

7.00

7.96

6.30

21.26

WL 357 HQ

6.91

8.29

6.41

21.60

Mean

6.89

7.73

6.42

21.04

LSD (0.05)

NSb

0.36

NSb

0.77







aYield at 88% dry matter. bNS: not significant at the alpha = 0.05 level.

Table 3. Variety source, year of release, fall dormancy, and level of resistance topests and diseases for alfalfa varieties in the 2006-2011 furrow-irrigated forage variety trial. Malheur Experiment Station, Oregon State University, Ontario, OR, 2008.

Release

Pest resistance ratingb

Variety

Source

year

FDa

BW

FW

VW

PRR

AN

SAA

PA

SN

AP

RKN

Lahontan

public

1954

6c

MR

LR

-

LR

-

MR

LR

R

-

-

Wrangler

public

1984

2

MR

R

LR

HR

LR

HR

HR

LR

LR

LR

Rustler II

Andrews Seed

1995

4

HR

HR

HR

HR

HR

R

HR

MR

R

-

Masterpiece

Simplot

2000

4

HR

HR

R

HR

HR

R

-

HR

R

R

DKA-42-15

Monsanto

2001

4

HR

HR

HR

HR

HR

R

HR

R

HR

-

WL 319 HQ

W-L Research

2002

3

HR

HR

HR

HR

HR

R

HR

MR

HR

LR

WL 357 HQ

W-L Research

2003

5

HR

HR

HR

HR

HR

R

R

MR

HR

LR

FC 1045

Andrews Seed

2005

4

HR

HR

HR

HR

HR

MR

R

R

R

MR

FC 1055

Andrews Seed

2006

5

HR

HR

HR

HR

R

R

R

HR

R

HR

FC 2055

Andrews Seed

2006

5

HR

HR

HR

HR

R

R

R

HR

R

HR

aFD: 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: Northern root knot nematode.

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

cFall dormancy: 1 = Norseman, 2 = Vernal, 3 = Ranger, 4 = Saranac, 5 = DuPuits, 6 = Lahontan.