Onion sets and storage rots
By Steve Roberts, 01 Jun 2011
There is a perception that the risk of certain onion diseases may be increased when crops are grown from sets. The major diseases of concern to the industry are: bacterial rots thought to be caused mainly by Burkholderia gladioli pv. alliicola (Bga; particularly in heat-treated red Rijnsburger type onions), neck rot caused primarily by Botrytis allii and Fusarium basal rot caused by Fusarium oxysporum fsp. cepae. One possibility is that the necessary heat treatment of some cultivars may lead to increased risk of disease. This HDC-funded project represents a first step to address these issues by determining the incidence of the major bacterial and fungal onion pathogens thought to be associated with sets of different types and establish if there is a relationship between disease incidence in sets and subsequent problems in the harvested bulb onion crop. It is anticipated that, based on these initial results, a follow-on project will investigate way of reducing the impact of any disease problems associated with sets.