BREAKING SEED DORMANCY OF SOME ANNUAL MEDICAGO AND TRIFOLIUM SPECIES BY DIFFERENT TREATMENTS

Abstract

The germination abilities of 14 annual legume species (six Medicago and eight Trifolium) were tested under three dormancy breaking treatments: In the first treatment, mechanical scarification plus sodium hypochlorite (MSS); in the second, chemical scarification with sulphuric acid (CSA); in the third, incubation in water bath at 90 °C (IWB) were used for breaking the dormancy. All Medicago species except for Medicago polymorpha showed improvement in germination rates using MSS. The seeds of M. polymorpha showed higher germination rates with CSA or IWB than MSS. For Trifolium species, results indicated that there was a great variability among species with regard to the treatments. Seeds of species showed a broad range of dormancy requirements for germination. The CSA treatment significantly increased the germination rates of Trifolium lappaceum, T. scabrum and T. strictum. On the other hand, the germination rates of T. spumosum, T. spadieceum and T. angustifolium were significantly improved by MSS. The seeds of T. badium showed higher germination rates with IWB than the other applications.