A FLOW-THROUGH HYDROPONIC SYSTEM FOR THE STUDY OF ROOT RESTRICTION

We have developed a flow-through system (FTS) to study the effects of root restriction stress on plants grown in hydroponic culture. The system was designed to permit the use of varied culture container volumes (from 25 to 1500 cm3) and dimensions (2.5 to 10 cm. dia. and 5 to 20 cm h.). The modular FTS design is divided into two nutrient delivery systems, one for large-volume containers and the other for small-volume containers. Each plant was grown in a modified Hoagland solution in a separate container. Nutrient solutions were aerated and the pH was automatically controlled at 6.0 +/- 0.2. This report describes the FTS and presents growth data for tomato plants (Lycopersicon esculentum Mill., cv. 'Better Bush') grown for a 57 day period. Our observations, when compared to the findings of a root restriction study made by Ruff, et al. 1987 (J. Amer. Soc. Hort. Sci. 112:763-769), indicate that similar characteristics result for the same tomato cultivar grown in either pot culture by Ruff, et al. 1987 (J. Amer. Soc. Hort. Sci. 112:763-769), indicate that similar characteristics result for the same tomato cultivar grown in either pot culture (soil) or hydroponics (FTS). The result of this test of the FTS supports the continued use of the system to study various physiological and hormonal parameters in relation to root restriction.