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Effects of chlormequat application on stem characteristics, yield and panicle conformation of winter oats

Published online by Cambridge University Press:  27 March 2009

M. H. Leitch
Department of Agriculture, University College of Wales, Aberystwyth, Dyfed SY23 3DD, UK
J. D. Hayes
Department of Agriculture, University College of Wales, Aberystwyth, Dyfed SY23 3DD, UK


The responses to treatment with chlormequat of winter oats at various rates of applied N were investigated in field experiments over two seasons. Chlormequat, applied at crop growth stage (GS) 32, significantly reduced stem length by an overall average of 25·3% in 1985/86 and 27·4% in 1986/87. The percentage reduction was not significantly influenced by variety or by the rate of N applied. All intcrnodes apart from the basal one were significantly shortened. The third internode from the base showed the largest percentage reduction and the uppermost internode the largest actual reduction in length, in all three varieties. Stem shortening was always associated with an increase in the weight per unit length of stem. In 1985/86 lodging in untreated control plots became more severe as N rate increased, but was completely controlled by the application of chlormequat at all but the highest rate (150 kg N/ha).

Combine-harvested grain yields of the variety Pennal in 1985/86 and of Bulwark and Pcnnal in 1986/87 were reduced where chlormequat had been applied. Hand-harvested samples from these treatments did not show the same reductions in yield, but revealed a significant increase in the number of grains per panicle and a significant reduction in their mean individual weight. The grain characteristics of Peniarth were unaffected.

The lengths of the main-stem panicles and primary branches in the panicle were shortened as a result of chlormequat application. In addition, the degree of branching and the number of spikelets were increased in the lower third of the panicle but reduced in the upper two thirds. In both Bulwark and Pennal the numbers of sterile grains were increased by the application of chlormequat and, in Bulwark only, the number of fertile grains was reduced. In Peniarth the numbers of fertile and sterile grains were unaffected.

Research Article
Copyright © Cambridge University Press 1989

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Blackett, G. A. & Martin, G. I. M. (1970). The effect of chlormequat on grain yield and straw length of spring barley and spring oats. Experimental Husbandry 19, 95100.Google Scholar
Child, R. D., Adam, J. S., Atkins, H. A. & Arnold, G. M. (1984). Approaches to the control of yield formation in cereals with plant growth regulators. In Yield of Cereals, pp. 8592. Course Papers, National Agricultural Centre Arable Unit, Stoneleigh.Google Scholar
Clark, R. V. & Fedak, G. (1977). Effects of chlormequat on plant height, disease development and chemical constituents of cultivars of barley, oats and wheat. Canadian Journal of Plant Science 57, 3136.CrossRefGoogle Scholar
Gill, W. D., Lang, R. W. & Rodger, B. A. (1974 a). The effect of chlormequat and nitrogen on straw length, lodging and grain yield of spring oats. Experimental Husbandry 27, 5761.Google Scholar
Gill, W. D., Lang, R. W. & Rodger, B. A. (1974 b). The effect of chlormequat and nitrogen on straw length, lodging and grain yield of wheat. Experimental Husbandry 27, 5056.Google Scholar
Green, C. F. (1986). Modifications to the growth and development of cereals using chlorocholine chloride in the absence of lodging: a synopsis. Field Crops Research 14, 117133.CrossRefGoogle Scholar
Green, C. F., Dawkins, T. C. K. & McDonald, H. G. (1985). Influence of chlorocholine chloride on grain growth of winter barley (Hordeum disticlwnL. cv. Igri) in the field. Journal of Experimental Botany 36, 11261133.CrossRefGoogle Scholar
Green, R., Baldwin, J. H. & Roberts, H. W. (1986). Winter oat husbandry – results from ADAS trials 1982–84. Proceedings of the Second International Oat Conference (Ed. Lawes, D. A. & Thomas, H.), pp. 192. The University College of Wales, Welsh Plant Breeding Station, Aberystwyth, 15–18 July 1985.CrossRefGoogle Scholar
Humphries, E. C. (1968). CCC and cereals. Field Crop Abstracts 21, 9199.Google Scholar
Humphries, E. C. & Bond, W. (1969). Effect of CCC on cereals. Rothamsted Experimental Station Report for 1968, pp. 102103.Google Scholar
Leitch, M. H. & Hayes, J. D. (1987). Some effects of timing and rate of chlormequat application on development and yield of winter oats cv. Bulwark. In Plant Growth Regulators for Agricultural and Amenity Use (Ed. Hawkins, A. F., Stead, A. D. & Pinfield, N. J.), pp. 205208. BCPC Monograph No. 36. Proceedings of a Symposium organised by the British Crop Protection Council and the British Plant Growth Regulator Group, held at Reading, 5–7 January 1987.Google Scholar
Page, R. A. (1973). The use of CCC (chlormequat) on winter wheat. Experimental Husbandry 23, 5864.Google Scholar
Rudeforth, C. C. (1974). Soils in Dyfed. II. Soil Survey Record no. 24. Harpenden: Soil Survey of England and Wales.Google Scholar
Strass, F. (1981). CCC in Hafer? DLG-Milteilungen 96, 555556.Google Scholar
Tennenhouse, A. N. & Lacroix, L. J. (1972). Effects of (2- chloroethyl) trimethylammonium chloride (CCC) on certain agronomic traits of oats and triticale. Canadian Journal of Plant Science 52, 559567.CrossRefGoogle Scholar
Übelhör, W., Mangstl, A. & Reiner, L. (1984). Die Wirkung von CCC auf Ertrag und Ertragsstruktur bei Hafer, untersucht an der Datenbasis von ISPFLANZ. Zeitschrifl für Acker- und Pflanzenbau 153, 186199.Google Scholar
Ulmann, L. (1982). Vliv morforegula˘ních pravků na oves. Agrochémia 22, 6769.Google Scholar
Zadoks, J. S., Chang, T. T. & Konzak, C. F. (1974). A decimal code for the growth stages of cereals. Weed Research 14, 415421.CrossRefGoogle Scholar