Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Epidemiology of Alternaria species on linseed.

Abstract

Samples of linseed cv. Antares seed used for sowing field experiments in the UK had an incidence of 34% Alternaria linicola and 21% of other Alternaria spp. in 1989, and 4% A. linicola, 12% A. alternata and 13% A. infectoria in 1990, but infection was decreased by fungicide (prochloraz or iprodione) seed treatment. At max. emergence of the crops, the incidence of cotyledons with brown lesions was 8% in 1989 and 12% in 1990. In pot experiments using the 1990 seed the incidence of disease on cotyledons was greatest at 10°C and least at 19°, when germination was most rapid. The max. concn. of airborne Alternaria spores in the linseed crops was 230 spores/m3 in 1989 and 50/m3 in 1990. The incidence of Alternaria species on seeds increased rapidly when crops were maturing and these fungi could be isolated from the seeds several months after harvest. This paper was presented at a conference entitled Production and protection of linseed, held at Churchill College, Cambridge, UK, 18 Dec. 1991.