HYDROPONIC CUCUMBER PRODUCTION USING A NEW RECYCLABLE GROWTH SUBSTRATE AND IRRIGATION SYSTEM

Abstract

In the Canadian vegetable greenhouse industry, the traditional soilless substrate used in hydroponic production systems is costly to recycle and is undesirable as landfill. After more than five years of research and development, SRI Inc. in collaboration with the University of Guelph (UoG) has developed a system that incorporates a synthetic growth substrate with an internal irrigation system. This product is known as the Enviro-Grow System (EGS) and can be recycled at the end of its lifecycle using conventional recycling technologies (similar to recycling a plastic bottle). During spring 2008, we conducted a large scale cucumber production experiment comparing the EGS vs. conventional rockwool (RW). Plant development and yield were evaluated at a commercial hydroponic greenhouse facility located in the Niagara Region of Ontario, Canada. Each substrate treatment (the EGS and RW) contained 2,310 linear meters of substrate and 6,720 cucumber (Cucumis sativus 'Camaro') plants for comparison. Irrigation scheduling for both substrate treatments were determined by solar radiation accumulation and plant demand. Plants grown using the EGS exhibited a significantly higher relative growth rate (RGR) than plants grown in RW. This resulted in an earlier harvest date (by one day). No difference in yield was found between plants grown in the EGS vs. plants grown in RW.