Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 25, 1998
Publication Date: N/A
Interpretive Summary: White clover is a perennial forage legume and its growth in pastures is influenced by annual weather conditions. Understanding annual patterns of growth could improve management. In addition, white clover breeders have released plants having improved disease resistance and drought tolerance. The longevity of these improved types has not been compared with commercially-available varieties in a grazed environment. In this investigation, several improved types were grazed year-round by cattle for two to three years at two locations in Mississippi. Each month, plants were removed from the pasture and examined to determine how the plants responded to grazing as the seasons change. We found that the proportion of plant tissue that could produce new plants repeated a cyclical pattern each year, increasing in the fall and winter and declining during the spring and summer. However, because total production of plant tissue declined greatly after the second year, the number of surviving plants declined greatly by the third year. All of the white clover types had similar growth and longevity. It thus appears that further improvements need to be made in white clover to improve its longevity in pastures.
Technical Abstract: Annual growth patterns of grazed white clover (Trifolium repens L.) are not well understood in the southeast USA. Our objective was to compare seasonal changes in morphological traits of selected cultivars and germplasm that contribute to white clover productivity and persistence in continuously-stocked pastures. `Osceola' and `Louisiana S-1', and Brown Loam Synthetic No. 2 and Southern Regional Virus Resistant germplasm were sown in bermudagrass (Cynodon dactylon (L.) Pers.) pastures in September, 1993 at Mississippi State and Newton, MS and continuously-stocked with cattle (5- to 10-cm stubble). Stolon length, axillary bud viability, and seedling recruitment were measured monthly for the next two to three years. Stolon length of all entries increased to a maximum by June before declining to a minimum in October. Peak stolon production in the first, second, and third year after seeding at Mississippi State was 42, 123, and 59 m m-2. respectively. There were no monthly differences among the four entries for proportion of stolon nodes having live, active, or nonviable buds at either location. The proportion of nodes with live buds increased from 10 to 20% in October to 45% in March before declining during the spring. Despite abundant production, volunteer seedlings had little or no effect on general persistence during the experiment. The results suggest that white clover persistence cannot be based strictly on stolon propogation and that few differences in long-term persistence exist among current cultivars or germplasm.