The Effects of Different Vermicomposts on the Growth and Chemical Composition of the Pistachio Seedlings

Samples of different solid organic wastes (SOW) including cow manure (CM), pistachio wastes (PW),cotton residues (CR) and date wastes (DW) were collected from different regions of Iran andconverted to various vermicomposts. Each vermicompost had an iron-enriched counterpart producedby gradual addition of ferrous sulphate to organic wastes during the vermicomposting. Samples of aloamy soil were mixed with various proportions of prepared vermicomposts and pistachio seedlingswere grown in 3 kg pots filled with them, for six months. During the period of experiment, somegrowth indices such as seed germination percentage, leaf area index, leaf chlorophyll content, leavesnumber, stem diameter and photosynthesis rate were measured for each treatment. After growingperiod, shoot and root dry weights and also macro and micro elements were measured. Aftervermicomposting, there was a substantial decrease in organic carbon content, total K and electricalconductivity of organic wastes. However, the contents of ash, N, P, Ca, Mg and some micronutrientsincluding Fe, Mn, Zn and Cu increased in vermicomposted organic wastes. The pH of organic wastesshifted toward neutrality and their bulk densities were changed. There was a significant increase inseed germination, leaf area index, shoot dry weight and stem diameter in pots treated with 10%pistachio and cow manure vermicomposts in comparison with control and other treatments. Due tofungi growth and seed infection, germination did not occur in pots treated with date vermicompost sothis organic amendment was not a suitable component for potting media. Vermicomposts enrichedwith ferrous sulphate increased chlorophyll and Fe contents of leaves.

The Effects of Different Vermicomposts on the Growth and Chemical Composition of the Pistachio Seedlings Keywords:

Vermicompost , Wastes , Growth indices , Pistachio seedling