Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-19T05:17:15.121Z Has data issue: false hasContentIssue false

The effects of delayed sowing and weather on growth, development and yield of winter oil-seed rape (Brassica napus)

Published online by Cambridge University Press:  27 March 2009

N. J. Mendham
Affiliation:
Department of Agriculture and Horticulture, School of Agriculture, Sutton Bonington, Loughborough, LE12 5RD
P. A. Shipway
Affiliation:
Department of Agriculture and Horticulture, School of Agriculture, Sutton Bonington, Loughborough, LE12 5RD
R. K. Scott
Affiliation:
Department of Agriculture and Horticulture, School of Agriculture, Sutton Bonington, Loughborough, LE12 5RD

Summary

Sowing winter oil-seed rape cv. Victor late in autumn (late September or October) in seven seasons from 1970 to 1977 gave enormously variable seed yields, from 120 to 450 g/m2. All crops made little growth before winter, and yield was related to the size of the crop at flowering, a function of the length of time for radiation interception and growth between the ‘beginning of spring’, when mean temperatures rose consistently above 5 °C, and full flower in late May. A late spring in 1970 gave the poorest growth and lowest yield, whereas in 1977 an early spring coincided with late flowering to give exceptional growth, and yields higher than from any early sowing.

Crops sown in early autumn (before mid-September) produced more consistent seed yields, 280–360 g/m2, except in the dry year of 1976. All grew well in autumn, overwintered with a large leaf area, and once temperatures rose in spring, rapidly reached peak area and full flower in early May. They were all large at flowering, and yield was apparently limited more by post-flowering events.

With all sowings numbers of pods and seeds were largely determined during a 3-week phase in late May and early June, extending from full flower until most pod hulls had finished growing. Late sowings produced 3000–6000 pods/m2, and the number of seeds retained per pod varied widely, from 7 on a poorly grown crop to 22 on a well grown crop, thus expressing the yield potential determined by crop size at flowering. Early sowings, however, produced apparently excessive numbers of pods (6000–12000/m2) and few seeds per pod (6–10), so that yield varied little, regardless of crop size. Early in the phase, when the number of seeds was determined, the mass of yellow flowers at the top of the crop reflected or absorbed up to 60 % of incoming radiation, and then the large number of pods increasingly shaded each other and competed for assimilate, resulting in heavy seed losses. A high-yielding crop type may therefore need to incorporate the restricted pod production and good seed retention of some well-grown latesown crops with the reliability and desirable agronomic features of early-sown crops.

Final seed weight varied more between seasons (3·7–5·3 nag) than between sowings. Seed growth mainly took place after the number of seeds had been determined, the duration depending on temperature, but rate of growth apparently more on assimilate supply, a function of environmental factors and the number of competing seeds.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1981

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

REFERENCES

Agricultural Development and Advisory Service (1978). Oilseed Rape. Ministry of Agriculture, Fisheries & Food, Leaflet GFO 23, London.Google Scholar
Allen, E.J. & Scott, R. K. (1980). An analysis of growth of the potato crop. Journal of Agricultural Science, Cambridge 94, 583606.CrossRefGoogle Scholar
Brar, G. & Theis, W. (1977). Contribution of leaves, stem, siliques and seeds to dry matter accumulation in ripening seeds of rapeseed, Brassica napus L. Zeitschrift für Pflanzenphysiologie 82, 113.CrossRefGoogle Scholar
Bunting, E. S. (1956). Winter rape as an oil-seed crop. Agriculture, London 63, 1720.Google Scholar
Gallagher, J. N. & Biscoe, P. V. (1978). Radiation absorption, growth and yield of cereals. Journal of Agricultural Science, Cambridge 91, 4760.CrossRefGoogle Scholar
Gallagher, J. N., Biscoe, P. V. & Hunter, B. (1976). Effects of drought on grain growth. Nature 264, 541542.CrossRefGoogle Scholar
Gallagher, J. N., Biscoe, P. V. & Scott, R. K. (1975). Barley and its environment. V. Stability of grain weight. Journal of Applied Ecology 12, 319336.CrossRefGoogle Scholar
Gallagher, J. N., Biscoe, P. V. & Scott, R. K. (1976). Barley and its environment. VI. Growth and development in relation to yield. Journal of Applied Ecology 13, 563583.CrossRefGoogle Scholar
Gregory, P. J., McGowan, M. & Biscoe, P. V. (1978). Water relations of winter wheat. 2. Soil water relations. Journal of Agricultural Science, Cambridge 91, 103116.CrossRefGoogle Scholar
Hozyo, Y., Kato, S. & Kobayashi, H. (1972). Photosynthetic activity of the pods of rape plants (Brassica napus L.) and the contribution of the pods to the ripening of rape-seeds. Proceedings of the Crop Science Society of Japan 41, 420425.CrossRefGoogle Scholar
McGowan, M. (1974). Depths of water extraction by roots. Application to soil-water balance studies. Isotope and Radiation Techniques in Soil Physics and Irrigation Studies, International Atomic Energy Agency, Vienna, pp. 435445.Google Scholar
Mendham, N. J. & Scott, R. K. (1973). Oilseed rape – winter or spring? Arable Farmer 07 1973.Google Scholar
Mendham, N. J. & Scott, R. K. (1975). The limiting effect of plant size at inflorescence initiation on subsequent growth and yield of oilseed rape (Brassica napus). Journal of Agricultural Science, Cambridge 84, 487502.CrossRefGoogle Scholar
Mendham, N. J., Shipway, P. A. & Scott, R. K. (1981). The effects of seed size, autumn nitrogen and plant population density on the response to delayed sowing in winter oil-seed rape (Brassica napus). Journal of Agricultural Science, Cambridge 96, 417428.CrossRefGoogle Scholar
Monteith, J. L. (1977). Climate and the efficiency of crop production in Britain. Philosophical Transactions of the Royal Society of London B 281, 277294.Google Scholar
Morice, J. (1960). La sélection due colza d'hiver base sur étude des composantes du rendement. Annals Institut Nationale Récherche Agronomique, Paris, B 10, 85116.Google Scholar
National Institute of Agricultural Botany (1980). Varieties of oil-seed rape 1980. Farmer's Leaflet No. 9. Cambridge.Google Scholar
Norton, G. & Harris, J. F. (1975). Compositional changes in developing rape seed (Brassica napus L.). Planta, Berlin 123, 163174.CrossRefGoogle ScholarPubMed
Schuster, W. (1966). Untersuchungen über Spatsaatvertträglichkeit einiger Winterrapsorten. Bayerische Landwirtschaftliche Jahrbücher 43, 432449.Google Scholar
Scott, R. K., English, S. D., Wood, D. W. & Unsworth, M. H. (1973). The yield of sugar beet in relation to weather and length of growing season. Journal of Agricultural Science, Cambridge 81, 339347.CrossRefGoogle Scholar
Scott, R. K., Ogunremi, E. A., Ivins, J. D. & Mendham, N. J. (1973). The effect of sowing date and season on growth and yield of oilseed rape (Brassica napus). Journal of Agricultural Science, Cambridge 81, 277285.CrossRefGoogle Scholar