Effect of culture medium on growth and salt tolerance of goldenrain tree (Koelreuteria paniculata Laxm.)

Goldenrain-tree (Koelreuteria paniculata Laxm.) is a woody perennial ornamental tree, mainly used for landscape purposes. The aim of this study was investigation salt tolerance of this plant and the effect of cow manure and vermicompost on plant growth and increasing the salt tolerance of two-year plants. In a factorial experiment and completely randomized design (CRD), three levels of organic amendments (soil, 80% v/v soil + 20% v/v vermicompost, and 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 in greenhouse were applied. In this experiment, media without organic amendment was were considered as control and stress duration was three months. Results showed that increasing soil salinity levels progressively decreased the number of shoots and fresh and dry weights of roots, shoots, and whole plant while it increased activity of peroxidase and sodium and chloride uptake. Vermicompost treatment increased fresh and dry weights of shoots, roots, and whole plant, peroxidase, sodium, potassium, and chloride uptake more than control and cow manure. The highest fresh and dry weights of shoots, roots, and whole plant as well as sodium potassium and chloride uptake were obtained in salinity level of 4 ds/m and under vermicompost treatment. Generally, application of vermicompost increased growth characteristics and salt tolerance of goldenrain tree better than cow manure.