Potato minituber production from nodal cuttings compared to wholein vitro plantlets using low volume media in a greenhouse

Summary A greenhouse minituber production system involving low inputs of in vitro potato plantlets and propagation media is described, in vitro plantlets of six potato cultivars were sectioned into nodal cuttings and separately planted into moist peat based growing medium in shallow plastic trays. Cultivar differences were evident with respect to node viability, shoot regrowth and minituber yields. Nodal viability for shoot regrowth varied between 80–100%. Maximum shoot heights were recorded with whole in vitro plantlets (WIP) and the terminal Node-5 cluster. All cuttings produced minitubers. The terminal Node-5 cutting and WIP produced significantly larger minitubers >3.0 g as compared to single node cuttings. Greater numbers of minitubers were produced by the cvs Norchip, Red Pontiac and Conestoga as compared to cvs Eramosa. G8610-4PY and Shepody. Total numbers of minitubers were 3 to 5 times higher from each in vitro plantlet that was sectioned into nodal cuttings as compared with intact WIP: the yield ratios depended on cultivar.