Table 2.

Life form, time of germination and conditions involved in the two-step model for breaking of PY

			Breaking of PY
Family/species	Life form	Germination	Step I	Step II	Reference
Convolvulaceae
Cuscuta australis*	A	Summer	15/6 °C (dry)	35/20 °C (wet)	Jayasuriya et al. (2008a)
Ipomoea hederacea*	SA	Summer	≥25 °C	35/20 °C (dry)	Jayasuriya et al. (2009b)
Ipomoea lacunosa*	SA	Summer	≥20 °C (wet)	35 °C (RH >90 %)	Jayasuriya et al. (2008b)
Fabaceae
Medicago polymorpha	WA	Autumn	60/15 °C	35/10 °C	Taylor (1996a, b)
Medicago lupulina	SA	Spring	5 °C	15/6 °C	Van Assche et al. (2003)
Melilotus albus*	B	Spring	5 °C	15/6 °C	Van Assche et al. (2003)
Ornithopus compressus*	WA	Autumn	60/15 °C	48/15 °C	Taylor and Revell (1999)
Trifolium subterraneum	WA	Autumn	≥15 °C	60/15 °C	Taylor (1981)
Geraniaceae
Geranium carolinianum	WA	Autumn	≥20 °C	≤20 °C	This study
Erodium cicutarium	WA	Autumn	If seeds buried in soil (wet conditions)	Drying	Van Assche and Vandelook (2006)
Geranium columbinum	WA	Autumn	If seeds buried in soil (wet conditions)	Drying	Van Assche and Vandelook (2006)
Geranium dissectum†	WA	Autumn	If seeds buried in soil (wet conditions)	Drying	Van Assche and Vandelook (2006)
Geranium lucidum	WA	Autumn	If seeds buried in soil (wet conditions)	Drying	Van Assche and Vandelook (2006)
Geranium molle	WA	Autumn	If seeds buried in soil (wet conditions)	Drying	Van Assche and Vandelook (2006)
Geranium pusillum	WA	Autumn	If seeds buried in soil (wet conditions)	Drying	Van Assche and Vandelook (2006)

A, Annual; B, Biennial; SA, summer annual; WA, winter annual; RH, relative humidity.

* Species known to have sensitivity cycling (sensitive ↔ insensitive).

^† The present study shows that seeds of G. dissectum can become permeable under wet conditions without drying, hence they also have a one-step PY-breaking process.