Productivity and Quality of New Onion Varieties Bolting Resistant in Northeast Sonora, Mexico

Onion production is an appropriate alternative for northeast Sonora, Mexico (Magdalena River). However, seed varieties are needed that are adapted to the temperature conditions of this region and also have a high potential for quality and yield.  The objective of this experiment was to evaluate yield and quality of nine white onion varieties. The evaluation was carried out in Magdalena of Kino, Sonora (Magdalena, River) in Winter 2009–10. The evaluated varieties were: Azteca, Kristal, White Grano, Carta Blanca, Cirrus, Early Suprime, Nube, Virgin, and Stratus. The date sowing was October 6, 2009, and the date seedling trasplant establishment was on December 19, 2009. We used a plant density of 339,600 plants/ha in furrows with four rows using drip irrigation system. In this trial, we used a completely randomized design with four replications. The measured variables were yield, bulb weight, bulb diameter, and bolting. The harvest period harvest was May 10–17. The results indicated that the bolting was low in all varieties with a variation of  0.0% for the varieties 'Carta Blanca' and 'Virgin' to 0.76% for 'Suprime Early'. The highest yield were obtained from the varieties 'Kristal', 'Early Suprime', 'Cirrus' and 'Carta Blanca' with yields of 93.0, 92.5, 91.6 and 86.4 t·ha^-1,  respectively, while lower yields were for 'Nube' and 'Virgin' with 70.9 and 50.9 t·ha^-1. The Stratus variety (control) presented a yield of 71.4 t·ha^-1. The highest bulb weights were obtained from 'Cirrus', 'Kristal', and 'Carta Blanca' with 289, 268, and 262 g, respectively,  while the largest bulb diameter corresponded to 'Cirrus', 'Kristal', and 'Carta Blanca' with 8.6, 8.5, and 8.5 cm, respectively.