Observations on Pythium root rot of wheat and barley

Abstract

SUMMARY Pythium arrhenomanes Drechsler and P. graminicola Subramanian cause a pale brown soft rot of the young roots of wheat and barley but other fungi, including other Pythium species, can cause similar lesions. In surveys in 1967, 1970 and 1971, Pythium root rot was prevalent on wheat and barley at Rothamsted, Hertfordshire, Woburn, Bedfordshire, and Saxmundham, Suffolk. Incidence was greatest on barley, particularly on light soils, soils deficient in phosphate and in cool wet conditions. The greater susceptibility of barley to both P. arrhenomanes and P. graminicola was confirmed by inoculation experiments in the laboratory and glasshouse in which the disease severely restricted root growth.