Experiments were conducted to evaluate the effects of light and osmotic stress on seed germination, and effects of seed burial depth on seedling emergence of C. argentea. In the laboratory, germination was stimulated by light, but imbibing seeds in dark for 14 days followed by exposure to light for another 14 days resulted in maximum germination (84%). Similarly, germination in the laboratory was greater for seeds that had been after-ripened in moist soil at 5 or 10 cm deep (81% germination) than seeds after-ripened on the soil surface (33% germination). These results suggest that tillage or inter-cultivation operations in fields would encourage C. argentea seeds to germinate. Germination decreased from 78 to 14% as osmotic potential decreased from 0 to −0.6 MPa, and germination was completely inhibited at osmotic potential of −0.8 MPa. In the pot experiment, seedling emergence was 73 to 76% at depths of 0 to 1 cm but decreased sharply as depth increased thereafter, and no emergence was recorded at the 4 or 5 cm depths. The information gained from this study might contribute to its control.
