Resistência de cultivares e híbridos de cebola a tripes

Resistance to Thrips tabaci was estimated for onion cultivars ValeOuro IPA-11, Roxa IPA-3, Belem IPA-9, Texas Grano-502, Brownsville and Duquesa, and for the hybrids Dessex and Granex Ouro. The experiment was carried out under field conditions in Juazeiro, Bahia State, Brazil, without the use of chemical control. Leaf characters were evaluated at 26; 48 and 69 days after transplanting date (DAT), and yield characters were evaluated at 93 DAT. The experiment design was total randomized blocks with three replications. The cv. Duquesa showed the lowest number of immature forms of T. tabaci, which was associated with the lowest number of leaves and the largest degree of insertion between the central leaves, suggesting a nonpreference type of resistance. The cv. Duquesa and hybrids Granex Ouro and Dessex were mode\rately resistant to the thrips based on yield characters and on the number of immature forms of the insect.