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Virginia Cooperative Extension - Knowledge for the CommonWealth

Crop and Soil Environmental News, October 2002

Annual Ryegrass Variety Trial 2001

Chris Teutsch, Forage Extension Specialist; and Mac Tilson, Research Associate
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 83.3340 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


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