Stand regeneration of Alysicarpus and Desmodium germplasm in Louisiana

Alysicarpus Necker ex Desv. and Desmodium Desv. have potential for increased use as pasture legumes in warm-temperate and subtropical environments. Seven accessions of D. heterocarpon (L.) DC, and 40 accessions of Alysicarpus, primarily A. vaginalis (L.) DC., were evaluated in Louisiana in 1995 and 1996. Single-row plantings with three replications in randomized complete block designs were established at the Iberia, Rosepine, and Southeast Research Stations. Data collected were visual stand ratings during the 1995 and 1996 growing seasons. An uncharacteristic period of 96 h with only two brief afternoon periods above freezing in February 1996 at Rosepine provided an opportunity to discriminate among entries for winter hardiness and to identify individual plants from each D. heterocarpon entry possessing winter hardiness. Alysicarpus plants did not survive the winter, but several accessions produced reseeded stands in 1996. Performance of the Alysicarpus germplasm was substantially better at the Southeast Station than at other locations, while more Desmodium entries survived at Rosepine than at the other locations despite lower winter temperatures at Rosepine. The surviving D. heterocarpon plants provide a potential source of winter hardiness for development of a perennial warm-season pasture legume for the lower gulf coast region.