Onion (Allium cepa L.) is one of the most important vegetable crops in Brazil. It is attacked by insects and diseases, such as Thrips tabaci Lindeman (Thysanoptera: Thripidae), Botrytis squamosa (J.C. Walker), Alternaria porri (Ellis) and Colletotrichum gloeosporioides f.sp. cepae Penz. This work evaluated the incidence of thrips, onion leaf blight, purple blotch, and smudge in eight elite populations of the Embrapa's onion breeding program ("CNPH 6415", "CNPH 6074", "CNPH 6244", "CNPH 6400 Chata", "CNPH 6400 Redonda", "Valencianita" x "Aurora", "Primavera" x "Pera Norte" and "Pera Norte" x "Primavera") and eight commercial onion varieties ("Granex 429", "BRS Cascata", "Belém IPA 9", "Crioula Alto Vale", "Bola Precoce", "Primavera", "Régia" and "1015 Y"). In regions of high incidence of C. gloeosporioides, the recommended materials are "CNPH 6415", "CNPH 6074" and "CNPH 6244"; "CNPH 6415", "CNPH 6074", "CNPH 6244", "BRS Cascata", "Valencianita" x "Aurora", "Primavera" x "Pera Norte", "Belém IPA 9", "Bola Precoce", "Primavera" and "Régia" are recommended for A. porri high incidence; and of T. tabaci are "CNPH 6415", "CNPH 6074", "Granex 429", "Bola Precoce", "Primavera" and "Régia". The onion populations "CNPH 6415" and "CNPH 6074" are resistant to those two diseases and thrips. On the other hand, "CNPH 6400 Chata", "CNPH 6400 Redonda" and "1015 Y" are susceptible to C. gloeosporioides, A. porri and T. tabaci. All the studied materials were considered susceptible to B. squamosa.
Allium cepa; Thrips tabaci; Alternaria porri; Botrytis squamosa; Colletotrichum gloeosporioides
