Submitted to: Extension Service Bulletins
Publication Type: Other
Publication Acceptance Date: June 19, 2003
Publication Date: October 1, 2003
Citation: DUGAN, F.M., LUPIEN, S.L., SCHROEDER, B.K. PINK SEED OF PEA. EXTENSION SERVICE BULLETINS. 2003. Interpretive Summary: Pink seed is a disease normally associated with wheat, but has in Canada also been reported from field pea and common bean. The cause is a bacterium called Erwinia rhapontici. It also causes soft rot of rhubarb. Pink seed of pea is of minor importance, although severely affected lots can be subject to dockage. However, the disease symptoms mimic the appearance of pink-colored fungicides frequently applied to pea seed. Lots with suspected pesticide contamination may not be used for consumption. It is therefore critical to be able to distinguish symptoms of pink seed from the pink-colored coatings originating with fungicides.
Technical Abstract: Discolored seed of field pea (Pisum sativum L.) can display symptoms of pale, pink-brown to bright pink discoloration throughout the seed coat. Unlike the pink coloration resulting from application of pink-colored, pesticidal seed treatments, the coloration is permanent and cannot not be removed by extended washing. The causal agent of pink seed is a bacterium, Erwinia rhapontici (Millard) Burkholder. Pink seed of pea has been previously reported from Alberta, Canada, and seed discolored from infection by E. rhapontici has been temporarily impounded by the Federal Grain Inspection Service until the seed could be distinguished from that contaminated by fungicidal seed treatments. E. rhapontici also infects wheat, common bean, and rhubarb.