Effect of Indoor and Underground Storage on Efficient Vegetative Propagation of Dwarf Napier Grass (Pennisetum purpureum Schumach)

Dwarf, late-heading (DL) Napier grass is suitable for both cut-and-carry and grazing management due to sufficient yield and quality potential. This species can hardly produce viable seed, and thus vegetative propagation should be essential before winter in temperate regions of southern Kyushu. The objective of this study was to determine the efficient storage methods of DL vegetative propagation. Two experiments were carried out, the first focused on indoor storage of 10-node stem sections under room or chilling (10°C) conditions and the second, on underground storage of ten-node and one-node stem sections at 10 cm, 25 cm or 40 cm depth. After both storages, both of ten-node stem sections, cut into single nodes, and one-node stem sections were transplanted into the soil and counted for the emergence every month in 3 months of planting. In indoor-storage, while storage temperature hardly affected the emergence (P > 0.05), storage period significantly reduced the emergence percentage. In underground storage, while one-node storage achieved constantly 60% emergence, ten-node storage achieved a higher emergence at 80% under 25-cm and 40-cm depths. The results of the study suggest that underground storage of longer stem sections at 25 cm depth could be applied to practical vegetative propagation in the region.