Annual Ryegrass Variety Trial 2001

Livestock Update, November 2002

Chris Teutsch, Southern Piedmont AREC, Blackstone, VA

Annual ryegrass (Lolium multiflorum) is a cool-season annual bunchgrass that originated in Southern Europe. It is widely adapted and can be found throughout the world. In the United States, annual ryegrass is grown on close to 3 million acres. The majority of this acreage is found in the southeastern United States where it is utilized for winter pasture. Most annual ryegrass is sodseeded into permanently established warm-season grasses in order to extend the grazing season.

Annual ryegrass is both highly digestible and extremely palatable making it a desirable species to include in forage systems. In addition, annual ryegrass has high seedling vigor making well adapted to either conventional or no-till establishment. Under good growing conditions, annual ryegrass can produce grazable forage in as little as 45 days after establishment.

Selecting an Annual Ryegrass Variety
Climatic adaptation. An adapted variety will perform well across locations and years. Annual ryegrass varieties exhibit a wide range of winterhardiness. In Virginia, cold tolerance as indicated by winter survival is an important consideration in variety selection. A mild winter in 2001-2002 season resulted in no winter kill for any of the varieties in this trial. Therefore, differences in cold tolerance are not defined by this trial.

Yield and Forage Quality. Choose a high yielding variety with good forage quality. Yield is one of the most important factors in selecting an annual ryegrass variety. Another consideration is the yield distribution. Choose varieties that are most productive when forage demand is highest. For example if late spring forage is needed, choose a variety that possesses good growth during this period. Conversely, if late fall forage is needed, then a variety that produces the majority of its growth earlier may be a good choice. Forage quality and animal performance are also an important to consider, but basing variety selection on forage quality alone is not recommended. This trial reports the production of total digestible nutrients and crude protein on an area basis. In pasture situations individual animal performance is not always a good indicator of production efficiency. A better indicator is production on an area basis since an increased stocking rate often more than compensates for small losses in individual animal performance.

Seed quality. Buy high quality seed of a known variety. Seed should be free of weeds and possess a high germination rate. Buying certified or proprietary seed will ensure that you will get the genetics you are paying for. Use an improved variety that backs production claims with yield data from independent replicated trials. Although catchy names and producer testimonials help to sell seed, they are not always an accurate representation of actual performance. Order seed early to ensure availability and timely planting.

Establishment
Since annual ryegrass germinates rapidly and has excellent seedling vigor, it is well adapted to both conventional and no-till establishment. Sod supression is important when no-till seeding into an existing sod. This may be accomplished by close grazing prior to establishment and/or using a burn down herbicide such as paraquat at establishment. Pastures should be overseeded at rate of 30 to 35 lb/A in mid August to mid November. Seeding rates of up to 50 lb/A have been used (primarily by dairies) to increase stand density for management intensive grazing or haylage harvest. Areas in the Northern Piedmont and west of the Blue Ridge Mountains should use the earlier seeding date. Seed for conventional seedings should be broadcast and cultipacked on a fine, but firm seedbed. Since the seed size of ryegrass is relatively small, the seeding depth should never be greater than 1/2 inch.

At seeding, apply phosphorus and potassium according to soil test and nitrogen at a rate of 20 to 50 lb/A depending on the seeding date. Earlier seeding dates allow for increased fall growth and therefore require higher nitrogen rates. Later seeding dates use less nitrogen in the fall. When seeding into a bermudagrass sod, there may be significant competition for starter nitrogen if the sod has not gone completely dormant. In this case an additional application of 20 to 30 lb/A may be required in the fall.

Fertilization
Annual ryegrass responds well to nitrogen fertilization and can utilize up to 250 lb N/A per year. A general guide is to apply up to 50 lb/A at seeding, 50 to 75 lb/A in early spring, and 50 lb/A following each harvest. Early spring nitrogen stimulates early growth allowing for earlier grazing. When annual ryegrass is interseeded into a bermudagrass sod, latter nitrogen applications can be increased to stimulate bermudagrass growth.

Harvest Management
New seedings should be allowed to reach a height of 10-12 inches before grazing or clipping. Early fall seeding can produce significant growth and should be grazed or clipped to 3-4 inches to prevent matting during the winter months. Excessive matting can delay or reduce spring growth. In early spring, the plant is in the vegetative phase of growth and the apical meristem (growing point) is safely located below the grazing height. In this stage, grazing should be initiated at a height of 8-12 inches and terminated at 2-6 inches. As the plant matures, the vegetative growth changes to reproductive growth, stem internodes elongate and the growing point is elevated. At this stage grazing should be deferred until the early boot stage. This will allow for rapid regrowth from the crown buds.

When annual ryegrass is utilized as a short-lived annual, close and frequent grazing can be a better fit for most forage systems. This is especially true when annual ryegrass is sodseeded into a warm-season perennial pasture. In this situation close grazing in late spring is needed to reduce competition and allow the warm-season species to initiate growth.

Description of Variety Trial
Sixteen annual ryegrass varieties were evaluated at the Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA (Table 1). On 4 October 2001, plots were seeded at 35 lb/A using a cultipacker type seeder. Plots were irrigated with 1/2 inch water on 9 October 2001 to ensure uniform germination and emergence. The experimental design was a random complete block with four replications. Plot size was 6 x 20' with a 4' strip harvested from the center of each plot using a sickle bar type forage harvester. A subsample was taken from each plot at harvest for dry mater determination and forage quality analysis. Subsamples were weighed fresh and then dried for 5 days at 60 C and reweighed. At seeding, plots received 42 lb N/A and 120 lb/A of P2O5 and K2O. Plots were harvested on 28 February 2001, 9 April 2001, 10 May 2001, and 4 June 2001. Fertilization consisted of 100 lb N/A, P2O5 and K2O after the first harvest and 50 lb N/A after the second and third harvests. Samples were analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP) using a near infrared reflectance spectrophotometer (NIRS). After being scanned into the NIRS (Foss NIRSystems Model 5000, Silver Springs, MD), WINISI II software was used to select a calibration data set for wet chemistry determination (Infrasoft International, 2000). Neutral and ADF analysis were conducted using the ANKOM filter bag system (ANKOM Technologies, 2001). Total N was quantified using a modified Kjeldahl method. Crude protein was determined by multiplying total N by 6.25.

Using the Least Significant Difference to Make Mean Comparisons
Yield and forage quality can vary between plots due to differences in the soils, landscape position, and other factors that cannot be controlled or easily measured. The least significant difference (LSD) is used to determine if the difference between two varieties is large enough to be considered real at a given level of confidence (LSD (0.05)=95% confidence and LSD (0.10)=90% confidence). To be considered truly different the yield difference between two varieties must be equal to or greater than the LSD. For example if in this year's trial 'Marshall' yielded 10592 lb/A compared with 'Ribeye' that yielded 9085 lb/A for a difference of 1507 lb/A. The LSD (0.05) is 1051 lb/A, which is less than the yield difference. This means that we are 95% confident that 'Marshall' yielded more that 'Ribeye'. When varieties differ by less than the LSD they are considered not significantly different.

Results and Discussion
Weather data is shown is Table 2. Temperatures were generally mild during the winter months leading to no detectable difference in winter survival among varieties. Rainfall was below average for all but two months of the trial. Low rainfall during June limited regrowth after the fourth cutting. In normal years a late June cutting would have been taken.

Even with below average rainfall, the top yielding variety produced over 10,000 lb DM/A (Table 1). Yield differences among varieties were significant for all harvests except the first (Table 1). Neutral and acid detergent fibers were lowest for the earlier harvests and differed between varieties with in all harvest dates (Tables 3-6). Crude protein levels varied between harvests from an average low 13.4% for the second harvest to an average high of 20.0% for the third harvest. Crude protein differences among varieties were present for the second and fourth harvest only (Tables 3-6).

Total digestible nutrients were highest for the early harvests and varied among varieties within harvest dates for all harvests except the third (Table 3-6). Total CP and TDN yields are shown in Table 7. No significant differences among varieties were found for total crude protein production. However, total TDN production was greatest for 'Marshall' annual ryegrass and followed a declining trend similar to that of the DM yield resulting in a similar ranking. This reinforces the importance of selecting not only a variety high in forage quality, but also one that is high yielding.

Summary
Annual ryegrass has the potential to produce ample high quality forage in Virginia. It is most effectively utilized to overseed permanent warm-season pastures in the Southern Piedmont and Coastal Plains Regions of Virginia. While annual ryegrass can produce high yields of excellent quality forage, it does require significant inputs and should be considered an option only when permanent pastures are being effectively managed.

Table 1. Yield of annual ryegrass varieties at the Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA.

Variety	Seed Company	2-28-02	4-9-02	5-10-02	6-4-02	Total
		-------------------------------------------lb DM/A--------------------------------------
Marshall	Wax Company	2239	3602	3116	1636	10592
Passerel Plus	Pennington Seed	2076	3527	3095	1147	9845
Surrey II	CEBECO International	1907	3043	3203	1247	9400
FL/NEX2001	IFAS, Univ. of Florida	1721	3261	2929	1464	9375
Big Daddy	Southern States Co-op	2178	2764	3249	1122	9312
Abundant (1)	DLF-Jenks	2337	2824	3168	938	9267
Fantastic	Ampac Seed Company	2015	2872	3022	1355	9264
Abundant (2)	Ampac Seed Company	1955	2686	3525	1012	9178
Ed	Smith Seed Services	1916	2919	3016	1296	9147
Jumbo	Smith Seed Services	1981	2623	3455	1026	9085
Ribeye	Barenburg USA	1810	3041	2835	1399	9085
FL/OK2001	IFAS, Univ. of Florida	1495	3242	2825	1302	8863
TAM 90	East Texas Seeds	1777	2786	3015	1161	8740
Zorro	DLF-Jenks	1384	3017	2983	1308	8693
Winter Star	Ampac Seed Company	1546	2727	3402	984	8659
Feast II	Ampac Seed Company	1392	2360	2835	1252	7840
LSD (0.05)*		ns**	463	ns	ns	1051
LSD (0.10)		ns	386	411	347	876
* LSD, Fischer's protected least significant difference
**ns, not statistically significant

Table 2. Weather data for 2001-2002 growing season at the SPAREC, Blackstone, VA.

Month/Year	Temperature		Precipitation
	Average	Deviation*	Total	Deviation
	-------------------°F-------------------		-----------------inches----------------
October-2001	59.7	1.0	0.26	-3.09
November-2001	56.4	7.3	0.29	-2.80
December-2001	47.3	7.1	1.88	-1.31
January, 2002	44.0	6.4	3.56	+0.12
February, 2002	44.4	4.2	1.13	-2.21
March, 2002	50.5	3.1	4.70	+0.84
April, 2002	61.5	4.1	1.61	-1.72
May, 2002	65.8	0.1	3.00	-0.74
June, 2002	76.4	3.1	1.68	-2.19
*Deviation from SPAREC 53 year average temperature and rainfall.

Table 3. Harvest 1 (February 28, 2002) NDF, ADF, CP, TDN, CP yield, and TDN yield*.

Variety	NDF	ADF	CP	TDN		CP Yield	TDN Yield
	--------------------------------------%------------------------------------					-------------lb/A--------------
Marshall	26.8	14.0	14.7	84.7		339	1891
Passerel Plus	28.6	15.3	15.3	83.3		340	1710
Surrey II	30.7	17.4	17.0	81.0		348	1528
FL/NEX2001	30.2	16.3	16.6	82.3		290	1411
Big Daddy	33.0	18.6	16.6	79.5		362	1733
Abundant (1)	32.7	18.2	16.0	80.0		384	1865
Fantastic	32.3	17.5	15.0	80.1		300	1627
Abundant (2)	32.2	17.8	16.2	80.5		321	1570
Ed	30.6	16.9	15.5	81.5		307	1554
Jumbo	28.5	15.7	14.9	82.8		297	1638
Ribeye	30.8	17.1	14.7	81.0		269	1468
FL/OK2001	28.8	15.5	15.7	83.0		242	1235
TAM 90	33.9	19.1	16.8	79.0		300	1404
Zorro	27.6	15.3	15.5	83.3		220	1149
Winter Star	34.9	19.5	17.2	78.5		270	1215
Feast II	31.9	17.7	16.3	80.3		228	1121
LSD (P=0.05)**	2.4	1.4	ns***	1.7		ns	ns
LSD (P=0.10)	2.0	1.2	ns	1.4		ns	ns
*ADF, acid detergent fiber, NDF, neutral detergent fiber, CP, crude protein, and TDN, total digestible nutrients (calculated)
**LSD, Fischer's protected least significant difference
***ns, not statistically significant

Table 4. Harvest 2 (April 9, 2002) NDF, ADF, CP, TDN, CP yield, and TDN yield*.

Variety	NDF	ADF	CP	TDN		CP Yield	TDN Yield
	--------------------------------------%------------------------------------					-------------lb/A---------------
Marshall	39.7	24.1	18.2	73.5		651	2644
Passerel Plus	40.4	24.4	17.8	73.0		625	2577
Surrey II	40.9	25.1	20.1	72.5		605	2197
FL/NEX2001	41.2	25.3	19.9	72.0		648	2351
Big Daddy	38.7	24.6	21.8	73.0		600	2011
Abundant (1)	38.5	24.4	20.5	73.0		578	2063
Fantastic	40.8	25.3	20.1	72.0		577	2069
Abundant (2)	39.5	23.9	21.3	73.8		572	1976
Ed	41.6	24.9	19.6	72.5		566	2114
Jumbo	37.9	23.8	20.9	73.8		544	1930
Ribeye	42.0	25.6	18.8	71.8		558	2175
FL/OK2001	42.3	25.6	18.5	71.8		595	2325
TAM 90	40.5	24.8	20.4	72.8		568	2019
Zorro	39.5	24.3	19.7	73.0		593	2207
Winter Star	40.3	24.5	20.5	73.0		559	1988
Feast II	40.6	24.4	21.5	72.0		507	1697
LSD (P=0.05)**	1.7	1.1	2.1	1.3		68	319
LSD (P=0.10)	1.4	0.9	1.7	1.1		57	266
*ADF, acid detergent fiber, NDF, neutral detergent fiber, CP, crude protein, and TDN, total digestible nutrients (calculated)
**LSD, Fischer's protected least significant difference

Table 5. Harvest 3 (May 10, 2002) NDF, ADF, CP, TDN, CP yield, and TDN yield*.

Variety	NDF	ADF	CP	TDN		CP Yield	TDN Yield
	--------------------------------------%------------------------------------					-------------lb/A---------------
Marshall	53.5	33.1	13.1	63.5		405	1975
Passerel Plus	53.5	33.2	13.3	63.3		407	1948
Surrey II	55.5	34.7	14.8	61.8		476	1972
FL/NEX2001	56.1	35.2	14.9	61.3		435	1784
Big Daddy	61.9	38.5	12.0	57.3		389	1861
Abundant (1)	59.3	37.0	12.1	59.3		380	1868
Fantastic	57.9	36.1	13.8	60.0		416	1813
Abundant (2)	58.8	36.6	12.6	59.5		448	2096
Ed	56.8	34.9	13.9	61.3		414	1847
Jumbo	54.5	34.2	13.2	62.3		456	2144
Ribeye	58.0	35.9	14.0	60.0		397	1706
FL/OK2001	56.1	34.7	13.1	61.5		369	1735
TAM 90	58.7	36.6	13.5	59.3		401	1786
Zorro	52.6	32.8	13.6	63.8		405	1902
Winter Star	57.3	35.9	12.6	60.0		429	2050
Feast II	52.5	33.0	13.8	63.5		384	1798
LSD (P=0.05)**	2.1	1.2	ns***	1.3		ns	ns
LSD (P=0.10)	1.7	1.0	ns	1.1		ns	ns
*ADF, acid detergent fiber, NDF, neutral detergent fiber, CP, crude protein, and TDN, total digestible nutrients (calculated)
**LSD, Fischer's protected least significant difference
***ns, not statistically significant

Table 6. Harvest 4 (June 4, 2002) NDF, ADF, CP, TDN, CP yield, and TDN yield*.

Variety	NDF	ADF	CP	TDN		CP Yield	TDN Yield
	--------------------------------------%------------------------------------					-------------lb/A---------------
Marshall	57.0	34.4	13.1	61.8		214	1005
Passerel Plus	54.9	33.1	14.0	63.5		161	727
Surrey II	58.8	35.4	13.1	60.8		162	753
FL/NEX2001	56.6	34.2	14.4	62.3		207	903
Big Daddy	59.2	35.8	13.4	60.0		150	676
Abundant (1)	58.0	35.4	13.4	60.8		126	570
Fantastic	59.1	35.6	13.5	60.8		181	818
Abundant (2)	57.4	34.6	14.0	61.5		141	624
Ed	58.2	35.2	13.6	61.3		175	788
Jumbo	53.5	31.8	14.8	64.8		153	663
Ribeye	57.9	35.0	13.9	61.3		193	853
FL/OK2001	57.1	34.4	14.9	61.8		196	805
TAM 90	57.4	35.0	14.4	61.3		164	701
Zorro	50.9	30.4	15.1	66.3		192	865
Winter Star	53.5	31.7	15.3	64.8		151	638
Feast II	52.0	32.2	16.2	64.3		202	804
LSD (P=0.05)**	3.1	2.4	1.8	2.8		50	231
LSD (P=0.10)	2.6	2.0	1.5	2.3		42	193
*ADF, acid detergent fiber, NDF, neutral detergent fiber, CP, crude protein, and TDN, total digestible nutrients (calculated)
**LSD, Fischer's protected least significant difference

Table 7. Season total CP and TDN yield*.

Variety	CP Yield	TDN Yield
	---------------lb/A--------------
Marshall	1610	7515
Passerel Plus	1532	6961
Surrey II	1591	6449
FL/NEX2001	1580	6448
Big Daddy	1501	6280
Abundant (1)	1467	6367
Fantastic	1473	6327
Abundant (2)	1482	6267
Ed	1461	6303
Jumbo	1449	6376
Ribeye	1417	6202
FL/OK2001	1401	6100
TAM 90	1432	5911
Zorro	1410	6124
Winter Star	1409	5891
Feast II	1320	5418
LSD (P=0.05)**	ns***	811
LSD (P=0.10)	ns	676
*CP, crude protein, and TDN, total digestible nutrients (calculated)
**LSD, Fischer's protected least significant difference
***ns, not statistically significant

Contact Information: Chris Teutsch
Forage Research and Extension
Southern Piedmont AREC
2375 Darvills Road
Blackstone, VA 23824
434 292-5331
cteutsch@vt.edu

Visit Virginia Cooperative Extension