Onion is grown intensively in Burkina Faso for its economic importance. Unfortunately, it is attacked by various fungal diseases.
One of these diseases is the onion leaf spot, which has a real impact on the production. The aim of this study was to analyze
producers’ perceptions and to assess the incidence and severity of onion purple blotch in different cultivating areas of Burkina
Faso. To achieve this, surveys were carried out in 54 fields, which were spread over six provinces in the Sudanian zone, with
nine fields per province. In each selected field, three quadrats were placed on the diagonals and all the onion plants were
observed. Disease incidence and severity were assessed in each quadrat and producers’ perceptions were analyzed by
interviewing the owners of the selected onion farms using a questionnaire. According to producers, the disease was attributed to
five causes viz. overharvesting, insects, humidity, seeds and winds. The results showed that the incidence and severity of purple
blotch of onion were relatively high in all the provinces. The highest average incidence (62%) was observed in Oubritenga
province and the highest average severity (49%) was recorded in Kourweogo province. Symptoms of onion purple blotch were
observed on all varieties cultivated by the producers. The study also showed that farms using mineral fertilizers had the highest
incidence rate of 72%, compared to the use of organo-mineral fertilizers with rate of 44%. Onion yield losses due to disease
highlight the urgent need to development of an effective and sustainable control measures.

Burkina Faso; Incidence; Producers' perceptions; Purple blotch of onion; Severity