Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/25/1996
Publication Date: N/A
Interpretive Summary: White clover may be infected by several viruses in the United States. These viruses reduce white clover growth and persistence in the field. The only source of virus resistance in white clover is in the population SRVR. This study looked at SRVR and four other white clover varieties to see if the virus resistance in SRVR improved white clover yield and persistence. Seven studies were conducted for two to four years to see how different growing conditions affected this comparison. Under clipping with lawn mowers, SRVR had better yields and persisted longer than the other four varieties in most growing seasons. Future studies will be conducted in pastures to see if these results hold true under grazing by cattle. Virus resistance should be incorporated into new white clover varieties to improve white clover yield and persistence.
Technical Abstract: The objective of this study was to compare the virus-resistant white clover (Trifolium repens L.) germplasm SRVR with virus-susceptible cultivars for productivity and persistence under clipping in several different environments. Four cultivars and SRVR were broadcast-seeded in the field at Mississippi State, MS in the fall of seven different years. Dry matter yields were taken for 2-4 years after seeding using mowers for defoliation. Virus-resistant SRVR had greater dry matter yields than all four cultivars in the second year, greater than three of four cultivars in the third year, and greater than two of four cultivars in the fourth year. Relative yields at the final harvest of each study and white clover ground cover were greater for SRVR than for the other white clover cultivars. Multiple virus resistance in SRVR improved white clover productivity and persistance under clipping.