Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-25T00:15:52.319Z Has data issue: false hasContentIssue false
  • English
  • Français

The relative importance of some sources of root-weight variation in a carrot crop

Published online by Cambridge University Press:  27 March 2009

L. R. Benjamin
L. R. Benjamin
Affiliation:
National Vegetable Research Station, Wellesbourne, Wanwick, CF35 9EF
Get access Rights & Permissions [Opens in a new window]

Summary

The relative importance of some sources of plant-to-plant root-weight variation in a field-grown carrot crop was investigated in two experiments sown in contrasting soil conditions but using the same seed lot and experimental design. In each experiment the following possible causes of root-weight variation were recorded on an individual plant basis: umbel order and size of seed, sowing depth, time taken for seedling emergence, length of cotyledons at emergence, distance to nearest neighbours within a row and row position within the seed bed. The relative importance of these differing sources of root-weight variation was assessed by determining how much of the variation in In (root dry weight) they accounted for at two harvests in each experiment.

In the first experiment, carrot seeds were sown in warm, moist conditions in May. These conditions gave a near-ideal emergence, 82% of seedlings emerging over only 5 days. Thirteen days after sowing, the most important source of root-weight variation, out of the variables measured, was position of the row within the bed. However, approximately two-thirds of the root-weight variation could not be attributed to any of the measured variables.

In the second experiment carrot seeds were sown in hot, drying conditions in July. The subsequent spread of seedling emergence extended over approximately 40 days. The total sum of squares of In (root dry weight) in this experiment was six times greater than the sum of squares in the first experiment. At 105 days, 61% of the rootweight variation in Expt 2 was accounted for by differences in time of seedling emergence. Differences in cotyledon length, measured when fully expanded, accounted for 24% and sowing depth differences accounted for 19% of the root-weight variation. Differences in umbel order, seed size and distance to the nearest neighbouring plants within a row never accounted for more than 8% of the sum of squares of In (root dry weight) in either experiment. Thus these variables were not important sources of rootweight variation. In contrast variables which affected the time of seedling emergence, such as sowing depth and physical conditions around the seed, were major sources of root-weight variation.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 102 , Issue 1 , February 1984 , pp. 69 - 77
Copyright
Copyright © Cambridge University Press 1984

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

Austin, R. B. & Longden, P. C. (1967). Some effects of seed size and maturity on the yield of carrot crops. Journal of Horticultural Science 42, 339–353.CrossRefGoogle Scholar
Benjamin, L. R. (1982a). A model to predict the effects of complex row spacings on the yields of root crops. Journal of Agricultural Science, Cambridge 98, 131–139.CrossRefGoogle Scholar
Benjamin, L. R. (1982b). Some effects of differing times of seedling emergence, population density and seed size on root-size variation in carrot populations. Journal of Agricultural Science, Cambridge 98, 537–545.CrossRefGoogle Scholar
Bufton, L. P. (1978). The influence of seed-drill design on the spatial arrangement of seedlings and on seedling emergence. Ada Horticulturae 72, 135–157.CrossRefGoogle Scholar
Gledhill, H. J. V. (1970). A study of factors influencing root size in carrot crops. M.Sc. thesis, University of Dundee.Google Scholar
Gray, D. & Steckel, J. R. A. (1980). Studies on the sources of variation in plant weight in Daucus carota (carrot) and the implications for seed production techniques. In Seed Production (ed. Hebblethwaite, P. D.) pp. 475–484. London: Butterworths.Google Scholar
Hegarty, T. W. (1978). Seed bed conditions and seedling establishment. Ada Horticulturae 83, 297–308.CrossRefGoogle Scholar
Heoarty, T. W. & Royle, S. M. (1978). Soil impedance as a factor reducing crop seedling emergence, and its relation to soil conditions at sowing, and to applied water. Journal of Applied Ecology 15, 897–904.CrossRefGoogle Scholar
Heydecker, W. (1956). Establishment of seedlings in the field. I. Influence of sowing depth on seedling emergence. Journal of Horticultural Science 31, 76–88.CrossRefGoogle Scholar
Mann, L. K. & MacGillivray, J. H. (1949). Some factors affecting the size of carrot roots. Proceedings of the American Society for Horticultural Science 54, 311–318.Google 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
Salter, P. J., Currah, I. E. & Fellows, J. R. (1981). Studies on some sources of variation in carrot root weight. Journal of Agricultural Science, Cambridge 96, 549–556.CrossRefGoogle Scholar
Snedecor, G. W. & Cochran, W. G. (1967). Statistical Methods (6th edn). Ames, Iowa, U.S.A.: The Iowa State University Press.Google Scholar
White, J. M. (1978). Soil preparation effocts on compaction, carrot yield and root characteristics in organic soil. Journal of the American Horticultural Society 103, 433–435.CrossRefGoogle Scholar