Monitoring sclerotinia stem rot development in commercial canola crops in southern NSW

Abstract

Key findings • Sclerotinia stem rot is a very sporadic disease in southern NSW. Variations in the level of disease can occur between districts, between years and between paddocks. • The best indicators of a high sclerotinia risk district are a high intensity of canola production, frequent development of sclerotinia stem rot and reliable rainfall during flowering. • Preliminary results indicate prolonged periods (at least 48 hours) of relative humidity above 95% can trigger sclerotinia stem rot development. • A high level of petal infestation with Sclerotinia ascospores does not guarantee development of stem rot.