Black spot diseases in carrot

Summary

An important problem in organic carrot production in the Netherlands is the occurrence of black spots during storage. Several different fungal pathogens cause similar symptoms, which are collectively known as black spot diseases. We identified Alternaria radicina, A. dauci and Rhexocercosporidium carotae (syn. Acrothecium carotae) as the most prevalent black spot pathogens. We developed laboratory test methods for resistance to A. radicina and R. carotae, and assessed resistance in a collection of cultivated varieties and more exotic material.