Effect of gum inducer (ethephon) on yield and physico-chemical properties of gum exudate from Butea monosperma L.

Abstract

In present investigation an attempt was made to use ethephon as gum inducer for increasing yield of gum-butea and also test whether ethephon had any effect on physical and chemical properties of exuded gum. A field trial consisting of three methods of ethephon application viz., spray of ethephon on stem surface before knotching, spray of ethephon on stem surface after knotching, injection of ethephon at the base of tree trunk + knotching and only knotching (Control); and three doses of active substance of ethephon viz., 390, 780 and 1170mg/4ml was conducted on about 15 years old naturally growing trees of B. monosperma in 2013. Each treatment was replicated on three trees. The exuded gum was analysed for various physical and chemical properties in laboratory. Findings revealed that the yield of exuded gum- butea was significantly increased with the application of ethephon over control. However, doses of ethephon had no effect on gum yield. On an average, spray of ethephon on stem surface before knotching had yielded maximum gum (303.8g/m²) while, injection at the base of tree trunk the least (14.2g/m²). Application of ethephon as gum inducer also influenced some of the physical and chemical properties of butea-gum. Maximum solubility of gum-butea was found in acetone while least in water. Solubility and tap density were not affected by either methods or dose of ethephon. However, bulk density and compressibility index were significantly increased over control. The application of ethephon had no effect on pH, EC, ash and sugar content, while it caused significant decrease in nitrogen and protein content. Our study concludes that application of ethephon enhances gum exudation in Butea monosperma and also affects some of the physical and chemical characteristics of exuded gum-butea.