Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T02:05:25.641Z Has data issue: false hasContentIssue false
  • English
  • Français

Methods of analysing competition with special reference to herbage plants:III. Monocultures v. binary mixtures

Published online by Cambridge University Press:  27 March 2009

J. Hill
J. Hill
Affiliation:
Welsh Plant Breeding Station, Aberystwyth
Get access Rights & Permissions [Opens in a new window]

Summary

A model is presented which considers the effects of competition between pairs of individuals in binary mixtures. Competitive effects are defined in terms of two parameters; a monoculture effect (Mo) which measures competition between like individuals and a mixture effect (Mi) which relates to competition between unlike individuals. If the data from a particular density replacement series conform to the proposed model the ratio of Mi to Mo can be used to determine whether it would be more advantageous to grow a mixture of the two components concerned or a pure stand of the better component. Where appropriate the optimal composition of the mixture may also be estimated. Theoretical considerations suggest that a 50:50 ratio only represents the optimal composition of a mixture when the two components possess a similar expression for the character concerned.

The model has been applied to dry weight data collected over two growing seasons from a glasshouse experiment which contained 5 genotypes of Lolium perenne grown as monocultures and in all 10 binary combinations. Each combination was represented by three mixture proportions. For the majority of these density replacement series the model was satisfactory, with mixture effects tending to be of greater significance during the first of the two growing seasons. Failure of the model was in general due either to a specific form of competition, which maintained the performance of the mixtures at the level of the better monoculture, or to the presence of more complex forms of competition.

The implications of this model for the development of productive herbage mixtures are briefly discussed, whilst the possible effects of invasion by unsown grass species upon the productivity of a pure sward are also outlined.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 83 , Issue 1 , August 1974 , pp. 57 - 65
Copyright
Copyright © Cambridge University Press 1974

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Allard, R. W. (1960). Principles of plant breeding, 1st edn. pp. 485. New York: John Wiley & Sons, Inc.Google Scholar
Breese, E. L. & Hill, J. (1973). Regression analysis of interactions between competing species. Heredity 31, 181–200.CrossRefGoogle Scholar
Cavalli, L. L. (1952). An analysis of linkage in quantitative inheritance. Quantitative Inheritance H.M.S.O., London, 135–44.Google Scholar
Charles, A. H. (1961). Differential survival of grass cultivars in Lolium, Dactylis and Phleum. Journal of the British Grassland Society 16, 69–75.CrossRefGoogle Scholar
Charles, A. H. (1964). Differential survival of plant types in swards. Journal of the British Grassland Society 19, 198–204.CrossRefGoogle Scholar
Davies, , William, (1960). The grass crop, 2nd revised edn. pp. 363. London: E. and F. N. Spon Ltd.Google Scholar
de Wit, C. T. (1960). On competition. Verslagen landbouwkundig onderzoekingen, Nederlands 66, 1–82.Google Scholar
de Wit, C. T. & van den Bergh, J. P. (1965). Competition between herbage plants. Netherlands Journal of Agricultural Science 13, 212–21.CrossRefGoogle Scholar
Fisher, R. A. & Yates, F. (1957). Statistical tables for biological, agricultural and medical research, 5th edn. pp. 138. Edinburgh and London: Oliver and Boyd.Google Scholar
Harper, John L. & Clatworthy, J. N. (1963). The comparative biology of closely related species. VI. Analysis of the growth of Trifolium repens and T. fragiferum in pure and mixed populations. Journal of Experimental Botany 14, 172–90.CrossRefGoogle Scholar
Hill, J. (1973). Methods of analysing competition with special reference to herbage plants. II. Effects of associate plants. Journal of Agricultural Science, Cambridge 81, 91–98.CrossRefGoogle Scholar
Hill, J. & Shimamoto, Y. (1973). Methods of analysing competition with special reference to herbage plants. I. Establishment. Journal of Agricultural Science, Cambridge 81, 77–89.CrossRefGoogle Scholar
Mather, K. & Jinks, J. L. (1971). Biometrical genetics, 2nd edn. pp. 382. London: Chapman and Hall Ltd.CrossRefGoogle ScholarPubMed
Rhodes, I. (1970). The production of contrasting genotypes of perennial ryegrass (Lolium perenne L.) in monocultures and mixed cultures of varying complexity. Journal of the British Grassland Society 25, 285–8.Google Scholar
Stapledon, R. G. (1944). The land now and to-morrow. 3rd edn. pp. 334. London: Faber and Faber.Google Scholar
Thomas, V. J. (1970). A mathematical approach to fitting parameters in a competition model. Journal of Applied Ecology 7, 487–97.CrossRefGoogle Scholar
van den Bergh, J. P. (1968). An analysis of yields of grasses in mixed and pure stands. Verslagen landbouwkundig onderzoekingen, Nederlands 714, 1–71.Google Scholar