Fusarium diseases of peas

Abstract

Cultures of Fusarium oxysporum and F. oxysporum var. redolens , isolated from diseased pea plants growing in east England, differed in their pathogenicity. Most cultures of F. oxysporum behaved like the American physiologic race 1 of F. oxysporum f. pisi , but some were only weak pathogens and one infected pea varieties resistant to races 1 and 2. This is provisionally named race 3 A. A culture of F. oxysporum var. redolens caused a wilt indistinguishable from that caused by race 1 of F. oxysporum f. pisi . Pea wilt was the main cause of crop failures due to Fusaria up to mid-June. Pathogenic and non-pathogenic forms of F. solani were also isolated from diseased peas, but usually only after mid-June. From plants showing characteristic footrot, only F. solani was isolated, but towards the end of June many diseased plants had symptoms characteristic of both wilt and footrot. These symptoms are thought to resemble those previously called ‘St John's Disease’, and from such plants both F. oxysporum and F. solani were always isolated. When F. oxysporum f. pisi race I was inoculated to peas together with either pathogenic or non-pathogenic cultures of F. solani , the pea plants were less severely affected than when inoculated with race 1 alone.