J.B. HACKER1, WEN SHILIN2, YING ZHAOYANG3 and B.C. PENGELLY4
1CSIRO Livestock Industries, Brisbane, Queensland, Australia
2Soils and Fertilizer Institute, Chinese Academy of Agricultural Sciences, Beijing, China
3National Azolla Research Centre, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, China
4CSIRO Sustainable Ecosystems, Brisbane, Queensland, Australia
Thirty-four accessions of Chamaecrista rotundifolia, 3 of C. serpens, 3 of C. nictitans and one of C. pilosa were evaluated for potential for soil stabilisation and forage at 2 sites (Jianyang, Fujian and Guanshanping, Hunan) in the Red Soils Region of southern China. The C. rotundifolia accessions covered the geographic range of the species.
There were large differences in dry matter yield, flowering date and canopy height within C.rotundifolia. Some accessions from Paraguay and Argentina survived over winter at Jianyang, whereas accessions from lower latitudes, including cv. Wynn, failed to persist. One of these latter accessions also survived over winter at the colder site, Guanshanping.
For use as cut-and-carry forage, 2 accessions of C. nictitans (ATF 2217, 2219) showed considerable promise. In the trials (which were not harvested during the growing season), they had good ability to re-establish from seed, high yield, and, in some cases, rapid nodulation; 2219 also had good winter survival at one of the sites.
Variation in the accessions of C. rotundifolia showed strong relationships between latitude of provenance and flowering date, growth over the growing season and canopy height. Accessions
from equatorial regions were late-flowering and tall-growing whereas those from high latitudes were early-flowering and less robust. Early-flowering accessions were higher-yielding early in the season but comparatively lower-yielding late in the season, as compared with late-flowering accessions. Early-flowering accessions had higher seedling densities after winter than late flowering accessions at Guanshanping; but not at Jianyang, where seedling density after winter was consistently low (except for C. nictitans).
There was statistically significant variation in a range of attributes potentially associated with early and rapid establishment and accessions were identified which were, in some trials, superior to Wynn. Attributes included germination/ emergence, stem and root length of seedlings and seedling dry weight, and nodulation. However, in practice, the most important attributes influencing adaptation to the region were flowering date and survival over winter.