Behavior of various types of seeds of two species of yams tuber (Dioscorea cayenensis Lam. and Dioscorea rotundata Poir.) in Gabon

Low multiplication ratio of yam and scarcity of planting materials are major constraints militating against sustainable yam production. In order to evaluate the behavior of the four various types of seeds of two species of yams Dioscorea cayenensis and Dioscorea rotundata, cultivated on the experimental ground of the Higher National Institute of Agronomy and Biotechnology (INSAB), a test was realized in a randomized complete block design with six replications. The samples were cut and three levels of each tuber were used: proximal, medial and distal parts of the tuber. The fragments of tuber and the whole tuber represent the various types of seed used in this work. The results showed significant (P<0.05) differences in number of plants emerged and time of emergence in a mixture of 40% soil and 60% sand three months and half after planting. For all species, the proximal parts sprouted earlier than the medium parts and then the distal parts. The fragmentation of tubers in three (3) parts can show the existence of a gradient along the tuber in its potential for sprouting and growth. There was a highly significant (P<0.05) difference between yield performances after nine (9) months of culture. This technique improves the production of tubers in both species.