Growth and Yield of Eggplant ‘TNA-114’ as Affected by Planting Density and Coir Substrate Volume in Hydroponics

Eggplant hydroponics has recently increased in its forcing culture, so it is necessary to establish a cultural guideline.This study was conducted to assess effect of planting density and coir substrate volume on growth and yield in the hydroponics.Eggplants 'TNA-114', grafted on rootstock 'Tank One', were planted for the two experiments within a greenhouse in early September.The planting density treatments consisted of 2.9, 3.3, and 3.7 plants per m 2 in 3.3 L substrate volume.Substrate volumes were treated with 3.6 L and 9 L per plant at the density of 3.3 plants per m 2 .The cultivation rows were in the north-south direction, and two stems of the plant were trained to the east and west, respectively, for Y-shape.At 140 days after the planting, the 3.7 plantsm -2 density had 13% less internodes than the 2.9 plantsm -2 density and length of internode was 15% longer, but there was no significant difference among the treatments.Planting density did not affect yield per plant and fruit characteristics, but the 3.7 plantsm -2 density increased yield per 10 a to 18.6 tons, 20% and 17% more than the 2.9 plantsm -2 and the 3.3 plantsm -2 densities, respectively.Plant growth, yield, and fruit characteristics did not differ between two substrate volumes of 3.6 L and 9 L. From the results, we concluded that planting density for 'TNA-114' could be increased to 3.7 plantsm -2 with the substrate volume of 3.6 L/plant to improve the productivity in forcing culture.