the effect of the composted peanut shells as a growth medium on the growth of dracaena marginata

peanut shelles as a waste of cultivated peanuts are produced in a considerable amount in guilan province, iran, that its compost can be used as an available resource in replacement of peat as growth medium of ornamental plants.this experiment was carried out to determine the possibility using of peanut shells compost as an appropriate medium of dracaena. the control treatment was a medium of peat: perlit at 2:1 ratio that in a compeletly randomized design, the peat was replaced by composted peanut shelles by 15, 30, 45, 60, and 100% v/v. the experiment had three replications. this study was carried out in ornamental plant research station of lahijan, guilan province, iran. chemical properties of media including ec, ph, total nitrogen, carbon, c/n ratio; and available concentrations of phosphorus, potassium, calcium, sodium and magnesium were measured. the growth factors including plant height, leaf number, dry weight of stem and leaf were evaluated.the concentrations of nitrogen, phosphorus, potassium, calcium, magnesium, iron and manganese in leaf were also measured. results showed the peanut shell comopst because of decreasing c/n ratio and availability of nutrients in media, caused to increase plant height, leaf number and dry weight of shoot compared to control. the greatest rate of growth was achived in 15% and 45% compost treatments and its lowest obtained in 100% v/v treatment and control. in couclusion peanut shell comopste can be used as alternative substitution of expensive peat in the growth media of ornamental plants.