Competition between Clare and Seaton Park, and Clare and Daliak subterranean clovers in replacement series mixtures in the field.

摘要

Binary mixtures of Clare and Seaton Park, and Clare and Daliak subterranean clovers were ngrown for three years in de Wit replacement series in the field and defoliated at approximately n4-week intervals between mid-winter and the end of October. nFor the most part both mixtures exhibited competition for the same resources with Clare ndominant, and progressively excluding the other cultivars; this exclusion was more rapid with nDaliak than with Seaton Park. Seed production of both Seaton Park and Daliak was depressed nin mixtures, and seed reserves were reduced to virtually zero by the third year, although nsignificant growth and seed reserves remained in the monocultures. Seed production from nClare was much less dependent on plant population than was seed production from Seaton nPark and Daliak. Variation between replicates and spatial heterogeneity of sward composition nwas greater in the Daliak experiment on a heavy clay than in the Seaton Park experiment non a lighter soil. In both experiments, large quantities of seed could not be accounted for nin germinations and residual seed reserves-80% in 1986 and 33% in 1987. Significant seed nlosses may be characteristic of the ecology of subterranean clover in summer rainfall zones. nThe success of Clare in northern New South Wales may be due mainly to the vigour and nhigh seed production capacity of individual plants.