The modified growth and development of azalea plants by the application of vermicompost

ABSTRACT: The aim of this research was to assess the possible impacts of different levels of vermicompost on the growth, developmental and physiological characteristics of azalea (Rhododendron simsii), an important ornamental plant, to obtain the best and economic level. The induced changes by the application of five different concentrations of vermicompost including 0%, 25%, 50%, 75% and 100% were evaluated. The application of different levels of the used vermicompost had enhancing effects on plant growth and development as it was shown by the increased amounts of fresh and dry mass in leaf tissues as well as the enhanced leaf area. However, the highest applied levels of vermicompost, 100%, did not have desirable enhancing effects and the application of fewer levels were more effective where the best results were observed in V75 and V50 treatment groups. In addition to the vermicompost induced changes in plant growth rates, cellular metabolism was also affected by the applied treatments. The highest amounts of polyphenol oxidase activity, phenylalanine ammonia lyase activity, anthocyanin contents were found in V75 and V50 respectively. Our results indicated that the application of high levels of vermicompost may have adverse effects on plant growth and development which is in agreement with some other researches in these fields.