In the Canadian prairies, pulse crops such as field pea (Pisum sativum L.) and lentil (Lens culinaris L.) are economically important and widely grown.However, in recent years, root rot, caused by a variety of fungal and oomycete pathogens, including Aphanomyces euteiches, has become a limiting factor on yield.
In this study, we examined the impacts of nitrogen (N) fertilization and a commercial arbuscular mycorrhizal fungal (AMF) inoculant on pea and lentil plant health and agronomic production at three locations in Saskatchewan: Swift Current, Indian Head and Melfort.The AMF inoculation had no impact on root rot severity, and therefore is not considered a reliable Western Top method to manage root rot in pea and lentil.In contrast, N fertilization led to reductions in root rot in Swift Current, but not the other two sites.However, N fertilization did reduce nodulation.
When both pea and lentil are considered, the abundance of A.euteiches in soil increased from Ornithine pre-seeding to mid-bloom.A negative correlation between soil pH and disease severity was also observed.The high between-site variability highlights the importance of testing root rot mitigation strategies under multiple soil conditions to develop site-specific recommendations.
Use of N fertilizer as a root rot management strategy merits further exploration, including investigation into its interactions with other management strategies, soil properties, and costs and benefits.