In this research were evaluated the yield of onion cultivars under organic growth in the São Francisco Valley. Two field trials were evaluated, one at the Experimental Farm Station of Embrapa Tropical Semi-Arid, in Petrolina, in an ultisol type and the other at the Experimental Farm Station of Mandacaru, in Juazeiro, in a vertisol type, from February to October of 2005. The experimental design was of randomized complete blocks, with 18 and 14 cultivars, respectively, and four replications. In the ultisol, the total yield of bulbs ranged from 13.52 to 39.52 t/ha. The commercial yield ranged from 7.45 to 38.32 t/ha where the cultivars Brisa (38.32 t/ha) and São Paulo (35.86 t/ha) showed the highest yield without statistical difference; Cultivars Botucatu-150 (26.41 t/ha) and Pira Ouro (26.37 t/ha) also stood out with high yield without statistical difference. The cultivars Conquista (7.45 t/ha) and Crioula Alto Vale (7.81 t/ha) presented the worst performance. In the vertisol the total yield of bulbs ranged from 6.87 to 24.68 t/ha. The cultivars Texas Grano PRR (21.56 t/ha) and IPA-10 (17.50 t/ha) presented the highest yield, without statistical differences. The cultivars Crioula Alto Vale, CNPH-6348, CNPH-6436 and CNPH- 6206 presented no commercial yield.
Allium cepa; adaptation; competition; planting system; yield
