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Seed and Seedling Dynamics Over Four Consecutive Years from a Single Seed Set of Six Annual Medics (Medicago SPP) in North Syria

Published online by Cambridge University Press:  03 October 2008

P. S. Cocks
P. S. Cocks
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria
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Summary

The fate of seed of six annual medics produced in spring 1987 and used in the pasture phase of cereal-pasture rotations was followed over four years. The medics were sown at low and high density, and seed set beyond 1987 was prevented by cultivation in 1988, and by herbicides in 1989 and 1990. The breakdown of hard seed was measured in the summer and autumn of each year, and the number of seedlings was counted after the first seasonal rains in the final three years. The survival of seeds buried at three depths was monitored. Seed of Medicago noeana lived longer than that of M. rotata and M. polymorpha. Survival of M. rigidula and M. truncatula seed was intermediate and there was no effect of planting density on survival. Breakdown of hard seed was least in the first year and increased in the second and third years. Within any year breakdown began in late summer or early autumn, beginning earlier as the seed aged. Seed burial enhanced germination in the year following seed set, depressed it in the second and third years, and had little effect in the fourth year. The net effect of seed burial on survival was therefore slight. The results suggest that the use of medics that have harder seeds than currently available cultivars, and medics in which germination is delayed until late in the autumn, will increase the sustainability and productivity of cereal-pasture rotations in semi-arid areas.

Dinámica de semilla de los Medicago spp anuales en Siria

Type
Research Article
Information
Experimental Agriculture , Volume 29 , Issue 4 , October 1993 , pp. 461 - 472
Copyright
Copyright © Cambridge University Press 1993

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References

Abd El Monein, A. M. & Cocks, P. S. (1986). Adaptation of Medicago rigidula to a cereal-pasture rotation in north-west Syria. journal of Agricultural Science, Cambridge 107:179–186.Google Scholar
Beale, P. E., Lahlou, A. & Bounejmate, M. (1991). Distribution of wild annual legume species in Morocco and relationship with soil and climatic factors. Australian journal of Agricultural Research 42:1217–1230.CrossRefGoogle Scholar
Bolland, M. D. A. & Collins, W. J. (1987). Persistence of seed produced from single seed crops of subterranean clover on sandy soils near Esperance, Western Australia. Australian journal of Experimental Agriculture 27:81–85.Google Scholar
Cocks, P. S. (1988). Seed production and seed survival under grazing of annual medics (Medicago spp.) in north Syria. journal of Agricultural Science, Cambridge 110:455–463.Google Scholar
Cocks, P. S. (1990 a). Dynamics of flower and pod production in annual medics. 1. In spaced plants. Australian journal of Agricultural Research 41:911–921.CrossRefGoogle Scholar
Cocks, P. S. (1990 b). Dynamics of flower and pod production in annual medics. 2. In swards at low and high density. Australian journal of Agricultural Research 41:923–931.CrossRefGoogle Scholar
Cocks, P. S. (1992). Changes in the size and composition of the seed bank of medic pastures grown in rotation with wheat in north Syria. Australian journal of Agricultural Research 43:1571–1581.Google Scholar
Cocks, P. S. & Ehrman, T. A. M. (1987). The geographic origin of frost tolerance in Syrian pasture legumes. journal of Applied Ecology 24:678–683.Google Scholar
Cooper, P. J. M., Gregory, P. J., Tully, D. & Harris, H. C. (1987). Improving water use efficiency of annual crops in the rainfed farming systems of west Asia and north Africa. Experimental Agriculture 23:113–158.Google Scholar
Dennett, M. D., Rodgers, J. A. & Keatinge, J. D. H. (1983). Simulation of rainfall records for the site of a new agricultural development: an example from north Syria. Agricultural Meteorology 29:247–258.Google Scholar
Ehrman, T. & Cocks, P. S. (1990). Ecogeography of annual legumes in Syria: distribution patterns. journal of Applied Ecology 27:578–591.Google Scholar
Osman, A. E., Cocks, P. S., Russi, L. & Pagnotta, M. (1991). Response of Mediterranean grassland to phosphate and stocking rate: biomass production and botanical composition. Journal of Agricultural Science, Cambridge 116:37–46.CrossRefGoogle Scholar
Puckridge, D. W. & French, R. J. (1983). The annual legume pasture in cereal ley farming systems of southern Australia: a review. Agriculture, Ecosystems and Environment 9:229–267.Google Scholar
Quinlivan, B. J. (1971). Seed coat impermeability in legumes. journal of the Australian Institute of Agricultural Science 37:283–295.Google Scholar
Robson, A. D. (1990). The role of self-regenerating pasture in rotation with cereals in Mediterranean areas. In The Role of Legumes in the Farming Systems of the Mediterranean Areas, 217–236 (Eds Osman, A. E., Ibrahim, M. H. and Jones, M. A.). Dordrecht: Kluwer.CrossRefGoogle Scholar
Russi, L. (1989). Ecological and Physiological Aspects of Seeds and Annual Grasslands in a Mediterranean Environment. PhD thesis, University of Reading, United Kingdom.Google Scholar
Taylor, G. B. (1984) Effect of burial on the softening of hard seeds of subterranean clover. Australian journal of Agricultural Research 35:201–210.Google Scholar
Taylor, G. B. & Ewing, M. A. (1988). Effect of depth of burial on the longevity of hard seeds of subterranean clover and annual medics. Australian journal of Experimental Agriculture 28:77–81.Google Scholar
Taylor, G. B., Maller, R. A. & Rossiter, R. C. (1991). A model describing the influence ofhard-seededness on the persistence of an annual forage legume, in a ley farming system, in a Mediterranean-type environment. Agriculture, Ecosystems and Environment 37:275–301.Google Scholar
Taylor, G. B., Rossiter, R. C. & Palmer, M. J. (1984). Long term patterns of seed softening and seedling establishment from single seed crops of subterranean clover. Australian journal of Experimental Agriculture and Animal Husbandry 24:200–212.Google Scholar
Thomson, E. F., Rihawi, S., Cocks, P. S., Osman, A. E. & Russi, L. (1990). Recovery and germination rates of seed of mediterranean medics and clovers offered to sheep at a single meal or continuously. journal of Agricultural Science, Cambridge 114:295–299.Google Scholar