Outdoor Growing of Clean Edible Ginger Seed by a Pot-in-Pot-in-Pot Sub-Irrigation Method

摘要

Edible ginger {Zingiber officinale Roscoe) was grown outdoors in 9.5-liter pots (with drainage holes) filled with growing medium which nested in 10.3-liter pots with no drainage holes and were constantly sub-irrigated with 5 cm of nutrient solution. Vegetative rhizomes from a previous crop were cut into seed pieces (50 + 10 g) for planting the next crop. Seeding material has been maintained free of root-knot nematode (Meloidogyne incognita) and bacterial wilt (Ralstonia solanacearum) throughout 3 growing seasons. Yields were higher when 3 or 4 seed pieces were planted per pot, but the increased yield per pot was not proportional to the initial seed piece. The 9.5-liter pot size was too small, and this resulted in competitive yield loss, burst pots and somewhat malformed rhizomes. A plastic gutter placed over a row of pots diverted 40 to 50% of the rainfall which otherwise would have diluted the nutrient solution. The use of gutters increased yields during 2 high rainfall years, but had no significant yield effect during a drier year. Upside-down, 3-liter pots placed in 9.5-liter growing pots reduced the growing medium requirement and also resulted in greater yields during 2 of 3 years. The highest absolute yields per pot occurred when an upside-down pot was placed in the growing pot and rainfall was diverted by a gutter from pots planted with 3 or 4 seed pieces.