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Control of mean root weight in carrots (Daucus carota) by varying within- and between-row spacing

Published online by Cambridge University Press:  27 March 2009

L. R. Benjamin
Affiliation:
Horticulture Research InternationalWellesbourneWarwick CV35 9EFUK
R. A. Sutherland
Affiliation:
Horticulture Research InternationalWellesbourneWarwick CV35 9EFUK

Summary

Results are reported from four carrot experiments (1987/88) to measure edge effects in crops of different ages grown in beds. A wide range of cultivars, densities and contrasting row-spacing systems was used to determine how effectively these edge effects could be eliminated by increasing the seeding rate in the outer rows relative to that in the inner ones.

Edge effects were first significant between 50 and 100 days after sowing. Where each row was sown with the same quantity of seed, carrots in the outer rows were 1·5 to 2·0 times heavier than those in the inner rows.

Increasing the seeding rate in the outer rows to between 1·5 to 3·0 times that in the inner rows, whilst holding the overall density constant, resulted in equal mean root weight in all rows. There was no evidence of alternate large and small plants in successive rows across the bed, as has been suggested in the literature.

A previously published spacing model gave large systematic deviations when fitted to these data, but this was rectified by a simple modification to the model, which did not entail the incorporation of more parameters.

Type
Crops and Soils
Copyright
Copyright © Cambridge University Press 1992

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References

Benjamin, L. R. (1984). The relative importance of some sources of root-weight variation in a carrot crop. Journal of Agricultural Science, Cambridge 102, 6977.CrossRefGoogle Scholar
Bleasdale, J. K. A. (1973). Control of size and yield in relation to harvest date of carrot roots. Acta Horticulturae 27, 134142.CrossRefGoogle Scholar
Ministry of Agriculture, Fisheries and Food (1980). Carrots. Booklet 2268. Pinner, UK: MAFF.Google Scholar
McCullagh, P. & Nelder, J. A. (1990). Generalized Linear Models, pp. 291292. London: Chapman & Hall.Google Scholar
Mead, R. (1966). A relationship between individual plantspacing and yield. Annals of Botany 30, 301309.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, 465478.Google Scholar
Shinozaki, K. & Kira, T. (1956). Intraspecific competition among higher plants. VII Logistic theory of the C–D effect. Journal of the Institute of Polytechnics, Osaka City University D7, 3572.Google Scholar
Sutherland, R. A. & Benjamin, L. R. (1987). A new model relating crop yield and plant arrangement. Annals of Botany 59, 399411.Google Scholar
Thompson, R. (1972). Mini-carrots. Scottish Agriculture 51, 308312.Google Scholar
Thompson, R. (1976). The agronomic problems of growing vegetables for specific outlets. Scottish Horticultural Research Institute Association Bulletin 11, 1723.Google Scholar
Thompson, R. & Taylor, H. (1976). Plant competition and its implications for cultural methods in calabrese. Journal of Horticultural Science 51, 147157.Google Scholar