Improvement of production technology for seed yams (Dioscorea rotundata Poir.)

摘要

In Njombe, Cameroon, studies were undertaken to investigate different media which could replace sawdust for germination of yam minisets, and the effect of different types of mulch, plant staking, and different plant densities on seed yam yields, using 20- to 30-g minisets as planting material. Topsoil, sand, coffee husks and volcanic gravel could replace sawdust for germination of yam minisets. The latter 3 very porous media must be mulched in order to improve water retention, and watering frequency should also be increased to keep these media permanently wet, thus improving sprouting conditions. Mulching with black-and-white polyethylene, with the white side up, and plant staking increased seed yam yields, with a combination of the 2 practices giving the greatest yields. These treatments also provided the best conditions for the production of abundant high quality planting material. Yields increased with increasing plant density, while tuber size decreased. The proportion of marketable tubers (>200 g) was greater with mulch.