Effects of planting pattern and planting distance on growth and yield of turmeric (Curcuma longa L.)

The effects of planting pattern and planting distance on the growth and yield of turmeric (Curcuma longa L.) were examined in Okinawa Prefecture situated in southern Japan. The dry weights of shoot and rhizome (yield) of turmeric planted in a triangular pattern were heavier than those planted in a quadrate pattern. A 30-cm-triangular planting resulted in the heaviest shoot and rhizome yield among the planting patterns examined. Dry weight of shoot per unit land area (m(2)) was significantly heavier when planted at a 20- and 30-cm spacing than when planted with a larger spacing, whereas the highest yield was obtained when planted at a 30-cm spacing followed by 20- and 40-cm spacing. When turmeric was planted at a 20-cm spacing, rhizome could not expand properly, which ultimately resulted in the smaller rhizome compared with that planted with a larger spacing. The highest turmeric yield coupled with the lowest weed biomass was obtained on the two-row ridge in a 75-100 cm width compared with a one- or two-row ridge in a larger or smaller width. This study indicates that for reducing weed interference and obtaining higher yield, turmeric should be planted in a 30-cm-triangular pattern on two-row ridge in a 75-100 cm width.