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Seed yield and hardseededness of two amphicarpic pasture legumes (Vicia sativa ssp. amphicarpa and Lathyrus ciliolatus) and two annual medics (Medicago rigidula and M. noeana)

Published online by Cambridge University Press:  27 March 2009

S. Christiansen
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), PO Box 5466, Aleppo, Syria
A. M. Abd El Moneim
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), PO Box 5466, Aleppo, Syria
P. S. Cocks
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), PO Box 5466, Aleppo, Syria
M. Singh
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), PO Box 5466, Aleppo, Syria

Summary

Yields and hardseed breakdown of underground and aerial seeds in subterranean vetch (Vicia sativa ssp. amphicarpa) and lathyrus (Lathyrus ciliolatus) and aerial seeds of Medicago rigidula and M. noeana were compared at Tel Hadya, near Aleppo, in north Syria between 1990 and 1992. Underground and aerial seed and straw (mature herbage) yields were measured at maturity in the first spring, and hardseed breakdown over the following summer, autumn and winter. Regenerating herbage production was measured in the second spring.

In the establishment year (292 mm rainfall) the medics produced twice as much straw as the amphicarpic species. In contrast, seed yields were less than half: M. rigidula and M. noeana produced 412 and 110 kg/ha respectively, while subterranean vetch and lathyrus produced 1174 and 736 kg/ha. More than 95 % of the total seed yield of the amphicarpic legumes was underground. Underground seeds of the amphicarpic legumes were larger than aerial seeds, and almost 10 times as large as the medic seeds.

Seeds of all species were > 90% hard when newly set in summer. At the first seasonal rains > 95% of underground seed had softened, compared with 5 and 40% of the aerial seeds of vetch and lathyrus respectively. The medics remained > 90% hardseeded. In laboratory tests, embryo dormancy was observed in all species prior to the onset of first seasonal rains. For the amphicarpic legumes, but not for the medics, embryo dormancy persisted into winter. In the field, and after all germination events, 900–1430 seeds/m2 of subterranean vetch seed remained in the soil. This was considerably more than expected, based on the low levels of hardseededness and embryo dormancy observed in the laboratory. The results suggest that dormant seeds of the amphicarpic legumes need light to germinate.

In the second year (353 mm rainfall), regenerating M. rigidula produced 5·3 t/ha compared with 3·4 t/ha by the best subterranean vetch from approximately equal numbers of seedlings. The amphicarpic legumes germinated later and over a more extended period than the medics, indicating that they could become weeds in a cereal/pasture rotation. However, the results suggest that in drier areas or in drier years the vetches will compare favourably with the medics in most respects. Clearly, subterranean vetch and lathyrus have great potential for pasture improvement in dry areas.

Type
Crops and Soils
Copyright
Copyright © Cambridge University Press 1996

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References

REFERENCES

Abd El Moneim, A. M. & Cocks, P. S. (1986). Adaptation of Medicago rigidula to a cereal–pasture rotation in northwest Syria. Journal of Agricultural Science, Cambridge 107, 179186.CrossRefGoogle Scholar
Cavers, P. B. & Harper, J. L. (1966). Germination polymorphism in Rumex crispus and Rumex obtusifolius. Journal of Ecology 54, 367382.Google Scholar
Cocks, P. S. (1990). Dynamics of flower and pod production in annual medics (Medicago spp.). II. In swards at low and high density. Australian Journal of Agricultural Research 41, 923931.Google Scholar
Cocks, P. S. (1993). Seed and seedling dynamics over four consecutive years from a single seed set of six annual medics (Medicago spp.) in north Syria. Experimental Agriculture 29, 461472.CrossRefGoogle Scholar
Cooper, P. J. M., Allan, A. Y., Harmsen, K., Keatinge, J. D. H., Nygaarde, D., Saxena, M. & Islam, R. (1981). Soil water and nutrient research, 1979–1980. ICARDA Project Report No. 3. International Center for Agricultural Research in the Dry Areas: Aleppo, Syria.Google Scholar
Dennett, M. D., Rodgers, J. A. & Keatinge, J. D. H. (1983). Simulation of a rainfall record for the site of a new agricultural development: an example from northern Syria. Agricultural Meteorology 29, 247258.CrossRefGoogle Scholar
Ehrman, T. & Maxted, N. (1990). Ecogeographic survey and collection of Syrian, Vicieae and Cicereae (Leguminosae). FAO/IBPGR Plant Genetic Resources Newsletter 77, 18.Google Scholar
Hyde, E. O. C. (1954). The function of the hilum in some Papilionaceae in relation to the ripening of the seed and the permeability of the testa. Annals of Botany NS 18, 241256.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, 229267.Google Scholar
Quinlivan, B. J. (1971). Seed coat impermeability in legumes. Journal of the Australian Institute of Agricultural Science 37, 283295.Google Scholar
Taylor, G. B. (1984). Effect of burial on the softening of hard seeds of subterranean clover. Australian Journal of Agricultural Research 35, 201210.Google Scholar
Taylor, G. B. (1993). Effect of some characteristics of diurnal temperature fluctuations on the softening of hard seeds of Medicago polymorpha. In Proceedings of the XVII International Grasslands Congress, Palmerston North, New Zealand, pp. 256257.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, 7781.Google Scholar
Thompson, K. & Grime, J. P. (1979). Seasonal variation in the seed banks of herbaceous species in ten contrasting habitats. Journal of Ecology 67, 893921.CrossRefGoogle Scholar