Effect of Bio-Regulator and Trunk Diameter on Gum Production from Acacia senegal L. Willd

The experiment was conducted during four consecutive years from 2010 to 2013 at Grassland Research Station, Junagadh Agricultural University, Dhari on Acacia senegal L. Willd with three replications in Factorial Randomized Block Design (FRBD) tofind out propertime of ethephon application and trunk diameter for higher gum production. The treatment comprised of three levels of time of ethephon application (T₁-15^th February, T_2-1^st March & T_3-15^th March) and five levels of trunk diameters (D₁: 20-30cm, D₂: 31-40cm, D₃: 41-50cm, D₄: 51-60cm and D₅: 61-70cm). For ethephon application to the plants, a manually operated driller of 5mm diameter capacity was used tomake approximately 4-5cm deep transverse hole at one meter height on the trunk. For the treatment application, 100-ppm (5ml) ethephon solution was injected to trunk by using a syringe and hole was sealed immediately after the injection with the help of Bavistin treated moistened soil. Gum tears appeared (may be eccrine, granulocrine and holocrine) after couple of weeks. The data indicated that ethephon application on 1^st March in 51-60cm trunk diameter, plant gave the highest gum yield (104.83 g) per plant and higher net returns (Rs. 29.78/plant) with B: C ratio (3.45) followed by ethephon application on 1^st March in 61-70cm trunk diameter plant.