Ascochyta blight of lentils in western Canada: 1978 to 1980

Abstract

Ascochyta blight of lentils was reported in Canada for the first time in 1978. Surveys of seed samples clearly demonstrated that the disease was already widespread in Saskatchewan and Manitoba. The main symptoms of ascochyta blight consist of purplish-brown shrunken seed and white to tan-colored leaf, stem and pod lesions, which usually become speckled with black pycnidia. The causal organism is similar morphologically to Ascochyta fabae Speg. sensu Boerema & Dorenbosch but the authors prefer to retain the name A. lentis BondartzevaMonteverde & Vassilievsky because of the apparent host specialization of the pathogen. A field survey in Saskatchewan in the summer of 1979 showed very low levels of ascochyta blight in southern and west-central areas. More disease was present in the moister region north of Saskatoon. Reduction in seed quality due to the disease is probably more important than yield losses.