influence of substitution of peat with iranian zeolite(clinoptilolite) in peat medium on ficus benjamina growth

this experiment was designed to characterize the effects of size and concentration of an iranian clinoptilolite zeolite on the growth officus benjamina (starlight) in peat base media. ficus benjamina was stock rooted and grown in a peat consisting perlite (2: 1 v/v) (p: pe), zeolite (10, 20, 30 and 40 v/v %, two sizes 0.5-3 mm and 3-8 mm) instead of peat in p: pe (2: 1 v/v) media. ficus benjaminawas grown in the substituted media for 10 month under fiberglass cover greenhouse, with 4 pots for each treatment. the control consisted of p: pe alone without zeolite. the results showed that the substitution of 10-30 v/v % zeolites in control did not result in significant difference (p £ 0.05) in shoot and leaf fresh weight, shoot and leaf dry weight, shoot dry weight, leaf dry weight in comparison to control. instead, substitution of 10-40 v/v % zeolites instead of peat significantly increased media electrical conductivity (ec). there were no positive correlations betweenficus benjamina growth and the amounts of mineral-n in potting mixtures or concentration of nitrogen in leaves of plant. zeolite particle size significantly increased the ph in comparison with the control. with regard to the high relative price of peat with respect to natural zeolite, zeolite substitution in an amount of 10-30 vol. % is economically preferred.