Evaluation of Seed Yield And Viability of Forage Crops in Ghana

ABSTRACT

Three experiments were carried out at the university of Ghana Agricultural Research Station, Legon, from November, 1999 to November, 2000, to assess field establishment and seed yield of five forage crops at various harvest periods and how their germination can be enhanced to improve pasture production in the country. The studies also examined the influence of storage of the seeds at room temperature, fridge and cold room and duration of storage on seed viability. High seed yields were obtained for Macroptilium lathyroides and Macroptilium atropurpereum, which were 22.63 kg/ha and 22.40 kg/ha respectively when they were harvested at three weeks after flower opening. Yields of subseguent harvest were poor. The seed yields of Cenchrus ciliaris and Panicum maximum were significantly higher than that of Andropogon gayanus. Time of harvesting significantly (p,0.05) influenced seed yield in the forage legumes and the grasses being 13.33 kg/ha and 22.7 kg/ha in the 3rd week harvest respectively for C. ciliaris and P. maximum while that of Andropogon guyanus had 3.07 kg/ha. Germination percentage of M. lathyroides and M. atropurpureum seeds harvested at both three and four weeks after flowering ranged between 80.6% over the 4 months of storage under the various conditions. For the grasses C. ciliaris had germination percentage of between 18.2% and xi 30.7% while A. gayanus had between 5.4% and 13.2% over the study period with no germination for P. maximum. Coldroom storage gave higher germination percentage and rate of germination for M. atropurpureum. C. ciliaris and A. gayanus while storage in fridge gave highest germination percentage for M. lathyroides. Seeds of C. ciliaris and A. gayanus harvested at five week after flowering had highest germination percentage under the various storage treatments. A study to determine efficient methods of breaking seed dormancy in the legumes seeds revealed that mechanically scarified seeds of M. lathyroides and M. atropurpureum had highest germination percentages, with the grasses mechanically scarified seeds of C. ciliaris and A. gayanus had lower germination percentages. Soaking of seeds in water for 14 hours gave a high germination percentage for C. ciliaris compared to no treatment. Panicum maximum seeds did not germinate over the study period. It is recommended that seeds of M. lathyroides and M. atropurpureum should be mechanically scarified before sowing to enhance higher germination. Since seed shattering occurred greatly after the third week of harvest, effort should be made to harvest these legume and grass seeds early to avoid loss of seeds during harvest. It is also recommended that seeds of M. atropurpureum, C. ciliaris and A. gayanus Should be stored in a cold room in order to get higher germination percentage while M. lathyroides should be stored in a fridge. Vegetative propagation could be used to establish pastures from A. gayanus as low germination percentage was obtained from the seeds Finally, it is recommended that further studies should be carried out On P. maximum to find effective ways Of improving its germinability since the work done showed that none of the seeds germinated under the various dormancy breaking methods Or storage conditions.