Reaction of Selected Onion Cultigens to Pink Root under Field Conditions in New York

Abstract

Levels of pink root, caused by Phoma terrestris, were assessed on onion (Allium cepa) growing in organic soils on farms in three New York counties during 1987 to 1990. Both commercial cultivars and lines from the USDA breeding program (collectively = cultigens) were evaluated for pink root incidence early in the season and for pink root severity later in the season. Onions were infected by P. terrestris as early as 6 to 8 weeks after field seeding. At maturity, portions of the root systems of all onions in all cultivars had turned pink. The cultigens with fewest symptoms were Sweet Sandwich, Keepsweet II, Spartan Banner 80, and inbred line MSU5785B.