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A model to predict the effects of complex row spacings on the yields of root crops

Published online by Cambridge University Press:  27 March 2009

L. R. Benjamin
L. R. Benjamin
Affiliation:
National Vegetable Research Station, Wellesbourne, Warwick, CV35 9EF
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Summary

A mathematical plant competition model developed by Currah (1975), and subsequently modified by the author, is briefly described. The model has two useful properties: (a) it can cope with complex irregular row spacing systems such as occur in commercial practice and (b) it can be ‘calibrated’ to the yield values at any site by using data from previous crops.

Parameter values of the modified model are calculated for both carrot and red beet crops. At least 70% of the variation in these data could be accounted for by fitting the model, a performance which was similar to, but never as good as, fitting analysis of ariance models. There were no systematic deviations between the fitted and observed values.

Previously estimated parameter values were used to predict mean root weights of carrot and red beet storage roots. Overall agreement between predicted and observed data was good, although some systematic deviations occurred.

The practical value of the modified version of the model and its strengths and weaknesses are discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 98 , Issue 1 , February 1982 , pp. 131 - 139
Copyright
Copyright © Cambridge University Press 1982

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References

REFERENCES

Benjamin, L. R. & Fellows, J. R. (1980). Plant size variation in root crops. National Vegetable Research Station Report for 1979, pp. 98–99.Google Scholar
Berry, G. (1967). A mathematical model relating plant yield with arrangement for regular spaced crops. Biometrics 23, 505–515.CrossRefGoogle Scholar
Bleasdale, J. K. A. (1967). The relationship between the weight of a plant part and total weight as affected by plant density. Journal of Horticultural Science 42, 51–58.CrossRefGoogle Scholar
Bleasdale, J. K. A. (1973). Control of size and yield in relation to harvest date in carrot crops. Acta Horticulturae 27, 134–143.CrossRefGoogle Scholar
Currah, I. E. (1975). Some factors affecting the size of plants in the carrot crop. Ph.D. thesis, University of London.Google Scholar
Frappell, B. D. (1968). Plant density studies with red beet. M.Sc. thesis, University of Birmingham.Google Scholar
Goodall, D. W. (1960). Quantitative effects of intraspecific competition; an experiment with mangolds. Bulletin of the Research Council of Israel 8D, 181–194.Google Scholar
Nelder, J. A. & Mead, R. (1965). A simplex method of function minimization. The Computer Journal 7, 308–314.CrossRefGoogle Scholar
Salter, P. J., Currah, I. E. & Fellows, J. R. (1979). The effects of density, spatial arrangement and time of harvest on yield and root size in carrots. Journal of Agricultural Science, Cambridge 93, 431–440.CrossRefGoogle Scholar
Salter, P. J., Currah, I. E. & Fellows, J. R. (1980). Further studies on the effects of plant density, spatial arrangement and time of harvest on yield and root size in carrots. Journal of Agricultural Science, Cambridge 94, 465–478.CrossRefGoogle Scholar
Willey, R. W. & Heath, S. B. (1969). The quantitative relationship between plant population and crop yield. Advances in Agronomy 21, 281–321.CrossRefGoogle Scholar