J. S. Boyce , B. K. Bakshi

Abstract

Dying of sal is occurring in many localities, particularly on poor sites, throughout its range in India. Though no one cause could be ascribed, it is believed that generally dying is due to deteriorating site conditions, probably the most important single factor being lessened amount of soil moisture. A fungus Hypoxylon mediterraneum is constantly associated with dead and dying sal. The fungus is believed to be pathogenic following the loss of vigour in sal and hastens the death of trees or prevents their recovery. It is believed that improvement of site by proper silviculture will restore the health of the stands.

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B. K. Bakshi , J. S. Boyce

Abstract

Water blister disease in teak is noticed in certain plantations along rivers in Nilambur, Kerala state. It is characterized by exudation of light yellow sap in large quantity from the stem near ground level. As the sap dries up, it leaves a blackish discolouration on the stem. The cause appears to be physiological. In winter when trees become leafless, transpiration is cut down. Under conditions of high temperature and soil moisture, ischolar_main pressure builds up, forcing the sap to collect in the crevice of the wood, developed as a result of shake, in increasing quantity under pressure, till it finds its release through the thin bark. Though the diseased trees are not killed they become damaged in the wood and may be removed during improvement fellings and thinnings. It is advisable to avoid planting teak in very moist sites where water blister develops.

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B. K. Bakshi , J. S. Boyce

Abstract

A ischolar_main rot disease of sal caused by Polyprus shoreae results in top dying and death of trees in North Bengal and Assam. In many cases, the dying trees become windthrown due to ischolar_mains becoming decayed and loosing footholds in the soil. The disease is correlated with high rainfall. The fungus infects through healthy uninjured ischolar_mains, causing decay in the bark and sapwood. Heartwood is unaffected. The decay does not normally progress into the stem. Till the disease is worked out, the suggested control measures include removal of dying and dead trees and practising controlled burning to reduce soil moisture.

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