Persistence and productivity of ten perennial Urochloa genotypes with Stylosanthes species in far north Queensland

Abstract

Ten perennial accessions of 4 Urochloa species and Brachiaria decumbens cv. Basilisk were sown with a mixture of Stylosanthes species at 6 sites in north Queensland's dry tropics to measure their persistence, productivity and compatibility with legumes. Out of a total of 8 sowings, as 2 sites were resown, grasses failed to establish at all but 3 sites, and at 1 of these, on a sandy soil, they failed to persist. At the remaining 2 sites (Southedge and Boomerang), 4 years after sowing, all sown species were present as dense, weed-free stands averaging 61 and 37% sown grass and 20 and 38% legume by weight. Legume made up a higher proportion of dry matter yield late in the wet season than at the beginning of the wet season. Yield of Basilisk was above average at 9 of the 12 harvests at these 2 sites, while U. mosambicensis CPI 46876 and U. oligotricha CPI 47122 were each always above average at 1 of the sites. Legume yield was not related to sown grass. Yield of green leaf by sown grasses in spring was related to crown density rather than to genotype.