Incidence and Effect of Heartwood-Rot on Indian Sandalwood ( <i>Santalum Album</i> L,) and its Natural Durability Against Fungi: A Case Study of Sandalwood Reserve in Marayur, Kerala

Indian Sandalwood (<i>Santalum album</i> L.) is a semi parasitic and perennial tree, well known for its valuable sandalwood oil extracted from heartwood and roots. Extensive loss of heartwood as a result of its decay is observed in living trees and this has inspired the current study to investigate the health of sandalwood in Marayur sandalwood forest reserves. Located in Kerala, majority of the trees in Marayur are facing high mortality with the loss of heartwood. The current study evaluated the health status and heartwood-rot disease severity of each tree based on a particular disease grading system which revealed that only 16.67 % of the total trees were healthy while 1.5 % of them were dead. Statistical analysis revealed that increasing girth class of trees has a significant positive association with increased disease severity at a 0.05 level of significance. Laboratory analysis on the samples of the extracted trees confirmed the presence of major wood-rotters <i>viz., Allophoma tropica</i>, <i>Xylaria berteroi, Diaporthe</i> sp., <i>Fomes</i> sp., <i>Ganoderma appalanatum</i> and <i>Trametes</i> sp. and they are collectively responsible for the heartwood-rot. Durability assessment revealed that sandalwood is highly resistant (durability class I) against white-rot fungi (<i>viz</i>., <i>Trametes hirsutus</i> and <i>T. (Coriolus) versicolor</i>) and moderately resistant (durability class II) against brown-rot fungi (<i>Oligoporous placenta</i> and <i>Fomitopsis meliae</i>).