Summary
The critical concentration of a mineral element in plants is usually defined by reference to the curve relating yield to plant nutrient concentration. This curve alters shape depending on the stage of growth, species, and other factors such as light and temperature, so that the critical concentration also varies. It is shown that this effect could arise from two simple, but reasonable assumptions: first, that the percentage depression of growth rate due to nutrient deficiency is related by a simple diminishing-returns type function to plant nutrient concentration in a manner which is independent of growth stage: and second, that the absolute growth rate of non-limited plants declines as their weight increases beyond a certain value. If the critical concentration were to be defined in terms of percentage growth rate depression, it is possible that it would be found to be much less variable than it now seems. re]19760730
References
Carter, J. N., et al., Agron. J. 63, 669–674 (1971).
Cleaver, T. J., et al., Commer. Grower Oct 14, 470–1 (1972).
Greenwood, E. A. N., et al., Plant and Soil 23, 97–116, (1965).
Knoll, H. A., et al., Soil Sci. Soc. Am. Proc. 28, 400–403 (1964).
Richards, F. J., In Plant Physiology, F. C.Steward, Ed. Academic Press, New York, Vol VA p 1 (1969).
Scaife, M. A., Ann Appl Biol. 74, 119–128 (1973).
Scaife, M. A. and Jones, D. J., J. Agric. Sci. 86, 83–91 (1976).
Terman, G. L., et al., Agron. J. 68, 107–111 (1976).
Ulrich, A., Soil Sci. 69, 291–309 (1950).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Scaife, M.A., Barnes, A. The relationship between crop yield and petiole nitrate concentration at various growth stages. Plant Soil 46, 705–712 (1977). https://doi.org/10.1007/BF00015936
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00015936