Poria monticola Murr. on chir (Pinus longifolia Roxb.) in India.

Abstract

Poria monticola Murr. (= Poria microspora Overh.) has so far been known to occur naturally in North America (Canada and United States), where the fungus commonly causes heart rot of living trees (sitka spruce and Douglas fir) as well as decay of coniferous wood in service. The fungus is not known to occur naturally in Great Britain, and is only present in timber imported into the country from North America. During the Second World War, Messrs. Tata Aircraft, Ltd., Bombay, obtained from Canada a supply of 36,000 cii. ft. of sitka spruce for manufacturing aeroplane parts in India. A large number of the planks showed an infection in the form of brown streaks of rot running along the length of the grain. Isolations from the diseased wood yielded a fungus which resembled Poria monticola described in culture by Nobles1 and others. The pockets were superficial and therefore the rot was removed by planing off the surface, and any incipient decay that might have gone inside the wood was arrested by kiln seasoning. The growth of the fungus is also known to be checked if the moisture content of the wood remains less than 20 per cent, based on the oven-dry weight of the wood.