Extension de la pourriture molle du céleri branche en maraîchage périurbain de Yaoundé (Cameroun)*

Abstract

Celery, Apium graveolens var. dulce, is the most important leafy vegetable crop in the Nkolondom inland valley, which supplies the majority of vegetables destined for sale in Yaoundé (Cameroon). Celery is a traditional leafy vegetable, but in recent years the crop has been threatened by the extension of soft decay which reduces the period during which it can be grown by one third. As the bacterium Pectobacterium carotovorum, formerly called Erwinia carotovora, was identified as the causal agent, the harvest technique, which involves the phased removal of individual leaves, was suspected of facilitating the spread of the disease through scars left on the stems. Local cultivation practices were compared with standard practices in temperate regions (where celery originated), which differ in sowing, planting, and harvesting techniques. The results showed, firstly, that the extension of the disease was not due to the local harvesting technique, which is well adapted to the local market, and secondly, that better yields are obtained using the local technique. The recent extension of the disease could be due to a change in the variety of celery, which was introduced at the same time as the extension of the disease became apparent. The new variety was planted because of difficulties in importing celery seeds, thus highlighting the inherent risk of any poorly organized innovation in a vegetable sector.