Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-28T16:51:47.956Z Has data issue: false hasContentIssue false
  • English
  • Français

Weight, size and shape relationships and their uses in the study of graded yield data

Published online by Cambridge University Press:  27 March 2009

G. E. L. Morris  and
I. E. Currah
G. E. L. Morris
Affiliation:
National Vegetable Research Station, Wellesbourne, Warwick, CV35 9EF
I. E. Currah
Affiliation:
National Vegetable Research Station, Wellesbourne, Warwick, CV35 9EF
Get access Rights & Permissions [Opens in a new window]

Summary

For many horticultural crops the distribution of weight over size grades is of more importance than the total weight. This paper shows how simply determined features of interrelationships of the weight, size and shape of an individual in the crop can be combined to provide estimates of various aspects of the distribution of crop weight over size grades. The two relationships required are (i) the probability density function of the grading variable for the crop; (ii) a function relating the weight of an individual to the corresponding value of the grading variable.

The paper shows how each of these can be determined either from published data or by simple experiment. Examples using data on onions and carrots are given to illustrate this and also to show some of the more important practical applications of the methods. For example, they allow the results of grading with one set of size grades to be extrapolated to a different set of grades without recourse to further measurement or experimentation and this is illustrated using published data on carrots. Other possible uses are also discussed and outlined.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 100 , Issue 1 , February 1983 , pp. 211 - 220
Copyright
Copyright © Cambridge University Press 1983

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

Bleasdale, J. K. A. & Thompson, R. (1963). An objective method of recording and comparing the shapes of carrot roots. Journal of Horticultural Science 38, 232–241.CrossRefGoogle Scholar
Chapman, E. A. (1981). Methods of analysing yield from trials in which the produce is graded according to diameter. Journal of Agricultural Science, Cambridge 97, 55–68.CrossRefGoogle Scholar
Dowker, B. D. & Fennell, J. F. M. (1974). Heritability of bulb shape in some north European onion varieties. Annals of Applied Biology 77, 61–65.Google Scholar
Giesbrecht, F. & Kempthorne, O. (1976). Maximum likelihood estimation in the three-parameter log-normal distribution. Journal of the Royal Statistical Society, Series B 38, 257–264.Google Scholar
Johnson, N. L. (1949). Systems of frequency curves generated by methods of translation. Biometrika 36, 149–176.CrossRefGoogle ScholarPubMed
Mead, R. (1965). A generalised logit-normal distribution. Biometrics 21, 721–732.CrossRefGoogle ScholarPubMed
Rogers, I. S. (1978). The influence of plant spacing on the frequency distribution of bulb weight and marketable yield of onions. Journal of Horticultural Science 53, 153–161.CrossRefGoogle Scholar
Willey, R. W. & Heath, S. B. (1969). The quantitative relationships between plant population and crop yield. Advances in Agronomy 21, 281–321.Google Scholar