Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-03T00:47:57.709Z Has data issue: false hasContentIssue false

The growth and performance of rain-grown cotton in a tropical upland environment: II. The relationship between yield and growth

Published online by Cambridge University Press:  27 March 2009

A. B. Hearn
Affiliation:
Cotton Research Corporation, Cotton Research StationNamulonge, P.O. Box 7084, Kampala, Uganda.*

Abstract

SUMMARY

An hypothesis, based on Mason's nutritional theory of boll shedding, was set up to relate the yield of cotton to crop growth in three agronomic experiments. It was postulated that bolls were set only if the demand for carbohydrates of the metabolic sink which they formed did not exceed the supply, both of which were estimated. Two components of the sink were recognized — the daily growth rate of a single boll, DGRB, and the number of bolls on the crop plants. The effects of genotype and environment on these components were analysed. Their product gave the size of the boll sink, CB, which was compared with the crop growth rate, C, to indicate respectively carbohydrate demand and supply. Three sets of evidence to support the hypothesis were considered: (i) when CB > C, the number of bolls, and hence the size of the sink, ceased to increase, and bolls started to shed heavily; (ii) a model to predict yield, based on the hypothesis, accounted for all non-random variation in yield between sowing dates and varieties; (iii) the correlation between yield and various crop attributes, recorded before picking, became strikingly closer between 110 and 130 days from sowing when CB > C, suggesting that yield was determined during that period of time. The network of relationships, studied in these papers in order to relate the yield of a cotton crop to its environment and genotype through their effect on its growth, indicates the form of a dynamic model to simulate growth and predict yields.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1972

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

Cognée, M. (1968). Abscission of cotton fruiting organs. Cot. Fibr. trop. 23, 315–36.Google Scholar
Dale, J. E. (1959). Some effects of the continuous removal of floral buds on the growth of the cotton plant. Ann. Bot. N.S. 23, 636–49.CrossRefGoogle Scholar
Dale, J. E. (1962). Fruit shedding and yield in cotton. Cott. Grow. Rev. 39, 170–6.Google Scholar
Eaton, F. M. & Erqle, D. R. (1952). Fibre properties and carbohydrate and nitrogen levels of cotton plants as influenced by moisture supply and fraitfulness. PL Physiol. 27, 641–62.CrossRefGoogle Scholar
Hearn, A. B. (1967). Prog. Rep. Exp. Stna Oott. Res. Corp. Uganda, 1966–7, 32–5.Google Scholar
Hearn, A. B. (1969a). The growth and performance of cotton in a desert environment. I. Morphological development of the crop. J. agric. Sci., Camb. 73, 6574.CrossRefGoogle Scholar
Hearn, A. B. (1969b). The growth and performance of cotton in a desert environment. II. Dry matter production. J. agric. Sci., Camb. 73, 7586.CrossRefGoogle Scholar
Hearn, A. B. (1972a). Cotton spacing experiments in Uganda. J. agric. Sci., Camb. 78, 1325.CrossRefGoogle Scholar
Hearn, A. B. (1972b). The growth and performance of rain-grown cotton in a tropical upland environment. I. Yields, water relations and crop growth. J. agric. Sci., Camb. 79, 121–35.CrossRefGoogle Scholar
Hesketh, J. & Low, A. (1968). Effect of temperature on components of yield and fibre quality of cotton varieties of diverse origin. Cott. Grow. Rev. 45, 243–57.Google Scholar
Leonard, E. R. (1962). Interrelations of vegetative and reproductive growth with special reference to indeterminate plants. Bot. Rev. 28, 353410.CrossRefGoogle Scholar
Morris, D. A. (1964). Variation in the boll maturation period. Cott. Grow. Rev. 41, 114–23.Google Scholar
Rijks, D. A. (1967). Optimum sowing date for yield: a review of work in the PB52 cotton area of Uganda. Cott. Grow. Rev. 44, 247–56.Google Scholar
Wit, C. T. De (1965). Photosynthesis of leaf canopies. Versl. Landbouwk. Onderz. No. 663.Google Scholar