Ocañera onion (Allium cepa L.)cultivars under protected and open field conditions.

Abstract

Introduction. Given its importance in food in different countries, the reduction of its genetic diversity, the loss of its beneficial traits, together with its resistance to diseases and pests; it is important to evaluate onion (Allium cepa) cultivars in different environments to know their adaptation. Objective. To evaluate the agronomic performance of onion cultivars under different environments to identify the best in adaptation, yield and interaction. Materials and methods. At the La Selva Research Center of the Colombian Agricultural Research Corporation (AGROSAVIA), Rionegro, Antioquia, Colombia, 21 cultivars plus two controls: Peruana of the Aggregatum group and Yellow Granex of the Cepa, were evaluated under open field conditions and protected with plastic cover, using multilocation trials with a randomized complete block design and four replications. The bulb weight, number, length and diameter were evaluated by categories, together with the interaction of cultivars with these environments. Results. In open field, the highest yields of bulb weight and number of bulbs were obtained because temperatures were lower than those recorded under protected conditions. In protected environments, the cultivars of the Aggregatum group behaved as if they were of the Cepa group, producing a few large bulbs. The adaptation of the cultivars was different in the environments: in the open field, cultivars L55 and L63 presented the best yields while, under protected conditions, RPT20 and RPT11 were the best adapted. Conclusion. Environments significantly influenced the performance of the cultivars of the Aggregatum group with higher production of extra-large bulbs. The high and low-temperature contrasts that occurred in the environments protected with a plastic cover affected the yields of the cultivars, while the environmental conditions in the open field were favorable.