Development of Basal Stem Heating System with Plastic Tunnel and Branch Duct in Forcing Culture of Eggplant

Abstract

For the purpose of reducing heating costs, a basal stem heating system was developed using a heat duct at the ground parts of the plants in a plastic tunnel on the forcing culture of eggplant. The basal stem temperature under the heating system in the night was markedly (6.3°C) higher than that of the control, and the air temperature in the plastic tunnel was 3°C higher than that of the control even under the non-heating condition. The basal stem heating system accelerated the growth of the lateral shoots and fruit, and the number of harvested fruits and marketable fruit yields under the heating system were higher than those under the control. The marketable fruit yield under the heating system in the plastic house at 10°C was similar to that under the control at 12°C. Setting up the basal stem heating system was not costly (20,000 yen·10a⁻¹) since the heating system can be prepared using existing heating machines. It is, therefore, suggested that a basal stem heating system with a plastic tunnel and branch duct is a useful and practical method for reducing the cost of the forcing culture of eggplant.