The Effect of Soil Cooling and High Intensity Supplementary Lighting on Flowering of Alstroemeria ‘Regina’

Abstract

Alstroemeria ‘Regina’ plants were grown at an air temperature of 15°/18°C (night/day). Soil cooling resulted in an increased number of flowering shoots in both spring-summer (21 Mar. to 20 Sept.) and fall-winter (21 Sept, to 20 Mar.) during the first year. Daily 16-hour supplementary lighting with high-pressure sodium (HPS) lamps reduced flowering shoots in spring-summer. In winter, only plants treated with the combination of soil cooling and HPS lighting produced flowers.