Onion varieties in vegetable cropping systems in Senegal

Onions constitute an important part of the total food consumption of Senegalese people. Due to particularly favourable conditions and to good cultivation practices, farmers from the Gandiolais zone, near the mouth of the Senegal River, are able to produce bulbs of many varieties from mid-December until September. However, production remains irregularly distributed within the year, and a quantity of onion must be imported for an annual value of US$5 million. The main constraints to a regular year-round production were identified and several cultivars grown worldwide were tested for their suitability. Results from experiments run in 1990-91 in the Centre pour le Developpement de l'Horticulture (CDH), and in 1991-92 in farmers' fields in Gandiolais, are presented. The main desirable characteristics are earliness, lack of premature bolting, short-cycle duration, total and marketable yield, and high dry matter content. Some cultivars could be recommended on these criteria, but the difficulties met by the farmers in mastering increasing infestations by pink-root disease emphasize the need to select resistant new varieties.