Effects of cow manure and vermicompost on growth characteristics of smoke tree (Cotinus coggygria Scop.) under salt stress under greenhouse

Smoke tree (Cotinus coggygria Scop.) is an attractive ornamental species that has medicinal properties. In this study, the effects of different levels of salt on plant growth and cow manure and vermicompost on increasing the salt tolerance of plant 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. In this experiment, media without organic amendment was considered as control. Results showed that increasing soil salinity levels progressively decreased the growth characteristics and fresh and dry weight of plant. The highest height and diameter were observed in control plants and in 1 dS.m-1 salinity. Vermicompost treatment better than control and cow manure increased fresh and dry weight of shoot. The highest fresh and dry weight of shoots by 230.8 and 123.36 g respectively, were obtained in the highest salinity level (7 dS.m-1) and vermicompost treatment. In moderate and high levels of salt stress (4 and 7 dS.m-1) vermicompost better than cow manure could increase leaf area. Cow manure and vermicompost could reduce sodium and chloride of leaf to control and increase its potassium. 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.