Effect of cow manure and vermicompost on decreasing salt stress in smoke tree (Cotinus coggygria Scop.)

Smoke tree (Cotinus coggygria Scop.) is an attractive ornamental tree in landscape that has medicinal properties. In this study, the effects of different levels of salt, cow manure and vermicompost on plant growth were investigated. In a factorial experiment and completely randomized design (CRD), three levels of organic amendments (1- soil 2- 80% v/v soil + 20% v/v vermicompost, 3- 80% v/v soil + 20% v/v cow manure) and three levels of salinity (1, 4 and 7 dS.m-1) with three replications per treatments were applied. Results showed that increasing soil salinity levels progressively decreased the fresh and dry weight of leaves, root, shoots and whole plant and increased sodium, potassium, chlorine uptake and catalase and peroxidase activity. The highest fresh and dry weight of leaves were obtained in cow manure and in 1 dS.m-1 salinity. The highest fresh and dry weight of root were obtained in vermicompost and in 4 dS.m-1 salinity. The highest fresh and dry weight of shoots were obtained in vermicompost and in 7 dS.m-1 salinity. The maximum amount of sodium, potassium and Na/K uptake were observed in 7 dS.m-1 salinity and vermicompost treatment. Application of cow manure and vermicompost in different salinity levels significantly increased catalase and peroxidase activity. Generally, the use of cow manure and vermicompost could improve the growth characteristics and nutrient absorption of plant under salt condition compare to the control.