Abstract

The study aimed to investigate the effect of the application of different concentrations of Methyl Jasmonate (JA-Me) on yield and quality of gum in Hashab (Acacia senegal) trees. Moreover, also studied the anatomy of the treated trees, and characteristics of gums produced. The study was carried out in two locations, Gedarif State (high rainfall area-clay soil) and North Kordofan State (low rainfall area- sand soil) in eastern and western Sudan respectively. JA-Me was applied at three different concentrations (50, 100 and 150 mg/L) as foliar spray and covered with plastic bags for 4-16hours to allow the JA-Me to enter into the tissues. The results showed that a suitable concentration of JA-Me for maximum gum yield per tree was 100 mg\L. The gum ducts in A. senegal trees treated by JA-Mewas wider compared to those of untreated (control) trees and finally one large duct was formed, where gum appeared as drops on the bark of the tree. There was no effect of JA-Me (100 mg/L) application on gum shape and colour when compared to the untreated control. The gum produced was red coloured spherical nodules with high solubility in cold water. The significance of the study and its outcomes is very important to treat the trees in areas of gum Arabic trees which have less capability to produce gums due to climatic changes and drought occurred in the areas of Acacia belt in Sudan. The study focused on areas of high production affected by environmental changes.

Key words: Sudan, gum Arabic, gum yield, natural hormones, gum duct, gummosis, Jasmonate.