Interaction of phosphorus and pistachio green hull on some growth characteristics and nutrients in pistachio (Pistacia vera L.) seedlings

To investigate the effects of phosphorus (P) and pistachio waste (raw and dry) on growth and chemical composition of pistachio (Pistacia vera L. cv. Badami Zarand) seedlings, a factorial experiment in a completely randomized design with four replications was conducted. Treatments were three levels of P (0, 50 and 100 mg P/kg soil) and three levels of pistachio green hull (0, 3 and 6% w/w). The results showed that at the first level of P application, the 3% pistachio waste treatment increased root and shoot dry weight, number of leaves and leaf area of pistachio seedlings. While, application of 6% pistachio hull significantly decreased these parameters, as compared to the control. However, root and shoot nutrient concentrations including P, sodium, zinc, iron and copper at the first level of P were reduced by pistachio waste application. At the first level of pistachio waste, P application increased root and shoot dry weight, number of leaves and leaf area of pistachio seedlings. But, all nutrient concentrations of root and shoots, except P, were reduced by increasing P level. The best response of dry weight of roots and shoots, number of leaves and leaf area of pistachio seedlings was observed from application of 3% pistachio hulls and 50 mg P/kg of soil. In general, the results of this experiment indicated that application of 50 mg P/kg soil was more effective than 100 mg P/kg soil on growth and chemical composition of pistachio seedlings. Application of 3% pistachio green hull and 50 mg P/kg soil improved growth of pistachio seedlings.