In the southern Great Plains (SGP) of the USA warm-season legumes can improve the quality of available forage in pasture systems based on perennial warm-season grasses. Legumes that persist through self-seeding may be...In the southern Great Plains (SGP) of the USA warm-season legumes can improve the quality of available forage in pasture systems based on perennial warm-season grasses. Legumes that persist through self-seeding may be especially useful in low-input systems where resources for annual replanting are limited. The productivity and capacity for self-seeding of Korean lespedeza (Kummerowia stipulacea [Maxim.] Makino) and Verano stylo (Stylosanthes hamata [L.] Taub.) were tested in controlled environment and in field plots in the SGP. At similar levels of accumulated temperature, germination of Korean lespedeza was unaffected by day/night temperature regimes between 15/15°C and 30/15°C. In contrast, at similar accumulated temperatures, germination of Verano stylo increased with higher daytime maximum temperature up to 30°C. Seedling growth of both species was reduced by shading, in proportion to the reduction in photosynthetic flux density. Growth of Korean lespedeza up to five weeks after emergence was greatest under a 22.5/7.5°C temperature regime but that of Verano stylo was greatest at 30/15°C. In the field Korean lespedeza was a prolific seeder and productive of forage though susceptible to significant loss of leaf material in late summer and fall. Verano stylo did not reseed effectively and was not a reliable forage producer.展开更多
文摘In the southern Great Plains (SGP) of the USA warm-season legumes can improve the quality of available forage in pasture systems based on perennial warm-season grasses. Legumes that persist through self-seeding may be especially useful in low-input systems where resources for annual replanting are limited. The productivity and capacity for self-seeding of Korean lespedeza (Kummerowia stipulacea [Maxim.] Makino) and Verano stylo (Stylosanthes hamata [L.] Taub.) were tested in controlled environment and in field plots in the SGP. At similar levels of accumulated temperature, germination of Korean lespedeza was unaffected by day/night temperature regimes between 15/15°C and 30/15°C. In contrast, at similar accumulated temperatures, germination of Verano stylo increased with higher daytime maximum temperature up to 30°C. Seedling growth of both species was reduced by shading, in proportion to the reduction in photosynthetic flux density. Growth of Korean lespedeza up to five weeks after emergence was greatest under a 22.5/7.5°C temperature regime but that of Verano stylo was greatest at 30/15°C. In the field Korean lespedeza was a prolific seeder and productive of forage though susceptible to significant loss of leaf material in late summer and fall. Verano stylo did not reseed effectively and was not a reliable forage producer.
