Carrot Decline (1992)

Report to the Oregon Processed Vegetable Commission

Mary Powelson and Robin Ludy
OSU Dept of Botany and Plant Pathology

A concern of carrot growers in the Willamette Valley is the decline in carrot productivity in fields that have been cropped
to carrots for more than one year. The cause of this yield decline has not been determined. Foliar leaf spots/blights can
cause a reduction in yield as can various nematode and fungal root diseases. Application of a soil sterilant and/or foliar
fungicide may help resolve whether this problem is biotic or abiotic in nature.


  1. Determine if the cause of yield decline in carrots is associated with a biotic cause.