STUDY BIOLOGICAL ACTIVITY OF EXTRACT ACTIVE SUBSTANCES OF ORANGE LEAVES IN CONTROL OF BLACK STEM DISEASE OF GRAPE PLANTS

Abstract

This study was conducted in the medicinal and aromatic plants unit laboratories at the College of Agriculture, University of Basrah, to investigate the effect of using orange leaf extract on controlling the blackening of the stem disease of grapes. A number of grape trees infected with stem blackening disease were selected by alcoholic extract of orange leaves at concentrations (0, 100, 200, 300 ml l-1). The alcoholic extract content of orange leaves of the active substances was estimated by GC-MS using a gas chromatograph coupled with mass spectrometry. The components were identified using the National Institute of Measurement and Technology (NIST) database by comparing the resulting spectrum of the unknown component with the known stored components in the NIST library. The detection showed the presence of 8 compounds in orange leaves, and the highest peak area of the extract was at 2.25 minutes for nHexane, and the lowest peak area was at 17.07 minutes for Copaene. The compound Ethyl Acetate appeared at 2.61 minutes with an area of 19.77 and Tetradecane at 19.47 with an area of 0.54. The different compounds varied in the time of their appearance, and the appearance of these eight compounds did not recur in different periods. The results of the study also showed that the treatment of orange leaf extract with a concentration of 300 ml l-1 recorded the highest percentage of response to extract, amounting to 70.94%, the highest percentage of the carbohydrate content of leaves amounted to 28.24%, the lowest percentage of phenols amounted to 0.65%, and the highest percentage of leaves content of chlorophyll amounted to 17.83