Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2002
Publication Date: 9/1/2002
Citation: VENUTO, B.C., BURSON, B.L., HUSSEY, M.A., REDFEARN, D.D., WYATT, W.E., BROWN, L.P. FORAGE YIELD, NUTRITIVE VALUE, AND GRAZING TOLERANCE OF DALLISGRASS BIOTYPES. CROP SCIENCE. 2002. V. 43. P. 295-301. Interpretive Summary: Common dallisgrass is an important forage grass in most pastures in the southeastern United States. It is best recognized for producing high quality forage. Besides common, there are several other dallisgrass types and they are called biotypes. Because little is known about the forage potential of these biotypes, forage evaluation plots were planted at Baton Rouge, LA and College Station, TX to determine how four different biotypes compared with common. Over a three year perod of mechanically harvesting the plots, a biotype from Uruguay consistently produced more forage than common and the other three biotypes. In Louisiana, the plots were on a poorly drained clay soil, and common dallisgrass did not persist well under clipping but the Uruguayan bioype survived and produced more forage. In Texas, the plots were on a better drained soil and both types survived well; however, the Uruguayan biotype produced more forage than common. The forage quality of the Uruguayan biotype was about the same as that of common. Plots of both common and Uruguayan dallisgrass were planted into an unimproved pasture at Jeanerette, LA and grazed with cattle to determine if the cattle preferred one grass over the other and to determine how they persisted under grazing. There appeared to be no difference in animal preference but the Uruguayan biotype persisted much better under grazing than common. It appears the Uruguayan biotype is better adapted to poorly drained clay soils than common and we plan to release this material as a new cultivar for cattle producers in the southern US.
Technical Abstract: Common dallisgrass(Paspalum dilatatum Poir.)is an important forage grass in many of the sub-tropical regions of the world including the southeastern USA. The term dallisgrass is synonymous with the common biotype; however, there are other biotypes of this species but little is known about their forage potential. This study was initiated to evaluate accessions from five dallisgrass biotypes(common, prostrate, Torres, Uruguaiana, and Uruguayan)and 'Pensacola' bahiagrass(P. notatum var. saurae Parodi)for forage yield, nutritive value, and persistence in southern Louisiana and southeastern Texas, and to determine the response and persistence of the superior biotypes under a grazing environment. Three years of clipping data were collected at Baton Rouge, LA and College Station, TX. Most of the Uruguayan accessions were equal or superior to common dallisgrass for yield and nutritive value and all had superior stand persistence. The Torres Uruguaiana biotypes did not survive after the first harvest season. Forage production and persistence of prostrate dallisgrass and Pensacola bahiagrass were better than expected. Six superior accessions of the Uruguayan biotype and common dallisgrass were evaluated for 3 years under a grazing management system at Jeanerette, LA. After 2 yr of rotational grazing, an average of 90% of the Uruguayan and only 53% of the common stands survived. This was followed by one season of continuous grazing and the average stand survival decreased to 75% for the Uruguayan accessions and 33% for common dallisgrass. Because the yield and persistence of the Uruguayan biotype was consistently superior to that of common, Uruguayan dallisgrass should provide livestock producers in the southeastern USA with a viable alternative to common dallisgrass.