EFFECT OF TEMPERATURE AND MOISTURE POTENTIAL ON GERMINATION AND EMERGENCE IN LOTUS SP

Two controlled cabinet experiments compared the germination of 6 Lotus genotypes over a range of temperature (0-40 degrees C) and moisture p otentials (0 to 1.2 MPa). A field experiment compared the emergence of 5 Lotus genotypes over 18 sowing dates. Lotus corniculatus cv. Grassl ands Goldie, L. uliginosus Grasslands Maku, G4703, G4704, and cv. Shar nae were included in both the controlled cabinet and field experiments . Lotus suaveolens CPI 35903 was included in the controlled cabinet ex periments only and Trifolium repens cv. Haifa was included as a contro l in the field study. Of the commercially available Lotus cultivars, G rasslands Goldie provides the greatest flexibility in terms of sowing date in coastal New South Wales and could be successfully sown even in late autumn and winter as it had the lowest base temperature for germ ination and field emergence. G4703, Sharnae, and G4704 had a lower bas e moisture potential for germination than the other 3 Lotus genotypes but this was not translated to better field emergence. Lotus suaveolen s had an extremely low base temperature for germination (1 degrees C) compared with L. uliginosus cv. Grasslands Maku (6.4 degrees C). Hybri disation of this species with both L. corniculatus and L. uliginosus c ould result in germplasm capable of germinating better at low temperat ure but still able to maintain the perenniality, rhizomatous habit, an d presence of condensed tannin of L. uliginosus.