Assessment of seasonal variability in gum exudation and gum yield in Palash (Butea monosperma L.) in semi-arid region of Central India

Abstract

Gum-butea (known as kamarkas) exuded from palash tree (Butea monosperma L.) is one of the key livelihood option for tribes particularly the Saharia community in Central India. In literature, sufficient information is available on tapping possibilities of B. monosperma for gum production, however, scientific information is lacking on gum exudation from Butea trees in different months and seasons of the year. Therefore, a study was conducted at ICAR-Central Agroforestry Research Institute, Jhansi to assess the variability in gum exudation and gum yield in different months and seasons of the year for suggesting best gum tapping month or season. A field trial was conducted on fully grown palash trees existing on research farm of the institute. For tapping trees every month throughout the year, 36 trees of palash were selected. Every month three trees were tapped. To induce gummosis, a sample stem area (SA) of 0.09m² (30*30cm) on every tree was knotched with the help of special billhook keeping the density of 45 cuts or knotches per SA and exuded gum when dried was collected after 3-4 days of making incisions. The trial was started in December 2021 and concluded in November 2022 and repeated in 2022-23. Findings based on two year’s experimental data revealed that exudation and gum yield varied significantly in different months and seasons of the year. Maximum gum yield was obtained in the month of December (40.80g/ SA) followed by January (39.5g) and February (26.1g). From December to June the gum yield declined reaching to the minimal in the month of July, August and September. The maximum potential total gum yield (613.5g/tree) was obtained in winter season (November to February) followed by summer (March to June) (223.4g/tree) and minimum (38.9g/tree) in rainy or monsoon season (July to October). The gum yield exponentially declined (R² 0.851) with the increase in rainfall. Conclusively, months of December and January of winter season are the best time to tap butea trees for maximum gum yield.