Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-24T22:35:57.341Z Has data issue: false hasContentIssue false
  • English
  • Français

Methods of analysis of a competition diallel in Italian ryegrass with varying mixture proportions

Published online by Cambridge University Press:  27 March 2009

A. J. Wright
A. J. Wright
Affiliation:
Plant Breeding Institute, Cambridge
Get access Rights & Permissions [Opens in a new window]

Summary

Two methods of analysis of variance of experiments involving diallel arrangements of binary mixtures and monocultures where the former are each represented by a linear replacement series (de Wit, 1960) to detect mean quadratic and quartic patterns among the monocultures and different mixture types, and array differences with respect to linear, quadratic, cubic and quartic effects are given. These are applied to data from an experiment on Italian ryegrass where the four varieties 1145 and S. 22 (diploid), IG2 and Tetila (tetraploid) are mixed in the proportions 75:25, 50:50 and 25:75.

Significant mean quadratic effects for D.M. yield at certain harvests are due to higher yields from monocultures than mixtures, and a mean quartic effect at one harvest reflects a lower yield from 75:25 mixtures than 50:50 mixtures or monocultures. Array differences for linear and quadratic effects are largely a property of the ploidy contrast. Specific mixture effects were recognized for two varietal combinations, mixtures between the two tetraploid varieties showing some yield depression, and those between the two commercial varieties (RvP and Tetila) a considerable increase. No meaningful significant effects were detected for in vitro digestibility.

Further analysis of total D.M. yield by means of the regression of array covariance (Wr) on to array variance (Vr) show, as expected, a closer relationship of Wr and Vr with the non-recurrent component at a frequency of 75% than at 50% or 25%, but the significant departure of the slope from unity is interpreted as evidence that no reliable information as to the relative competitive abilities of the varieties can be obtained from these statistics. Examination of the de Wit replacement graphs strongly suggests a ranking of competitive ability which accords with the known morphology of the varieties.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 84 , Issue 3 , June 1975 , pp. 431 - 444
Copyright
Copyright © Cambridge University Press 1975

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

Alcock, M. B. & Morgan, E. W. (1966). The effect of frequency of defoliation on the yield of mixtures of S 22 and Tetra Italian ryegrass in early establishment. Journal of the British Grassland Society 21, 62–4.CrossRefGoogle Scholar
Breese, E. L. & Hill, J. (1973). Regression analyses of interaction between competing species. Heredity 31, 181–200.CrossRefGoogle Scholar
de Wit, C. T. (1960). On competition. Verslagen land-bouwkundige onderzoekingen 66, 1–82.Google Scholar
Durrant, A. (1965). Analysis of reciprocal differences in diallel crosses. Heredity 20, 573–607.CrossRefGoogle Scholar
Fairfield Smith, H. (1957). Interpretation of adjusted treatment means and regression in analysis of covariance. Biometrics 13, 282–308.CrossRefGoogle Scholar
Harris, W. (1970). The prospects for mixing varieties of the L. multiflorum-L. perenne complex. Proceedings of the XIth International Grassland Congress, pp. 654–7.Google Scholar
Hayman, B. I. (1954). The analysis of variance of diallel tables. Biometrics 10, 235–44.CrossRefGoogle Scholar
Hill, J. (1974). Methods of analysing competition with special reference to herbage plants. III. Monocultures versus binary mixtures. Journal of Agricultural Science, Cambridge 83, 57–65.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
Jinks, J. L. & Hayman, B. I. (1953). The analysis of diallel crosses. Maize Genetics Cooperation Newsletter 28, 48–54.Google Scholar
McGilchrist, C. A. (1965). Analysis of competition experiments. Biometrics 21, 975–85.CrossRefGoogle Scholar
Morley Jones, R. (1965). Analysis of the half diallel table. Biometrics 21, 117–21.Google Scholar
Norrington-Davies, J. (1967). Application of diallel analysis to experiments in plant competition. Euphytica 16, 391–406.CrossRefGoogle Scholar
Rhodes, I. (1968). Yield of contrasting ryegrass varieties in monoculture and mixed culture. Journal of the British Grassland Society 23, 156–8.CrossRefGoogle Scholar
Thomson, A. J. (1969). Yields and tiller numbers of four perennial ryegrass varieties grown as monocultures and certain mixtures in micro plots. Journal of Agricultural Science, Cambridge 73, 321–8.CrossRefGoogle Scholar
Troughton, A. (1973). The development of leaf water deficits in plants of L. perenne in relation to the sizes of the shoot and root systems. Plant and Soil 40, 153–60.CrossRefGoogle Scholar
Whittington, A. J. & O'Brien, T. A. (1968). A comparison of yields from plots sown with a single species or a mixture of grass species. Journal of Applied Ecology 5, 209–13.CrossRefGoogle Scholar
Williams, E. J. (1962). The analysis of competition experiments. Australian Journal of Biological Science 15, 509–25.CrossRefGoogle Scholar
Wright, A. J. (1971). The analysis and prediction of some two factor interactions in grass breeding. Journal of Agricultural Science, Cambridge 76, 301–6.CrossRefGoogle Scholar