EFFECT OF GROWING MEDIA ON PLANT GROWTH AND NUTRIENT STATUS OF CRISP-HEAD LETTUCE

This research was carried out between the dates of October 30, 2002 and January 27, 2003. The objective was to compare the effects of clinoptilolite, which is a kind of zeolite, and perlite on growth and nutrient status of lettuce plants. Plant material was Lactuca sativa var. capitata cv. ‘Brogan’. Five different growing media; (1) perlite, (2) 3:1 perlite + zeolite, (3) 1:1 perlite + zeolite, (4) 1:3 perlite + zeolite and (5) zeolite were tested. Results showed that zeolite gave rise to increased plant growth and to reduced nitrate and nitrite contents in plant tissues. Mixing zeolite into the growing medium resulted in increased K, Fe, Cu and Mn, and decreased Mg content of the plants.