A HYDROPONIC SYSTEM FOR RAISING SPINACH SEEDLINGS

It was found that the germination percentage of spinach was increased by the use of a water absorption and chilling pretreatment (5°C, five days) and by the removal of the fruit coat from the seed. By the use of the latter method, especially, the seed was quite effective under a high temperature and saturated substrate condition. The substrate was made of vinylon fiber and remarkably raised the spinach seedlings establishment percentage. The facility which supplied the mature seedlings was composed of the following: a vinyl house, a clear vinyl tunnel for zone heating, growing beds, an irrigation controller, a heater, and a fog and fan equipment. In the facility the zone within the tunnel was heated to a temperature of about 15°C by the heater in winter, and was cooled by shading and by the fog and fan equipment in summer. A solution was supplied from the bottom of the substrate and controlled by the use of the timer. Using this system, the periods of raising seedlings were 14 days in winter, 10 to 12 days in spring and autumn, and seven days in summer.