Space restrictions do not allow us to deal with onion storage and transport technology issues here: a review that will include these topics is being prepared by Currah (2002). Onion storage and transport present several unanswered problems. Breeding for better storage qualities is already solving some of these, such as the short dormancy of some desirable types of onions. Others, such as identifying the correct conditions for sea transport of onions of different types, require cooperation between exporters, shippers and importers to pinpoint the optimum conditions attainable under shipboard conditions. The treatment of onions out of store is also the province of commerce rather than research at present, but research-based recommendations on this topic are badly needed. The onion trade continues to expand internationally and the advent of a distinct 'organic onion' as a commodity may well need research inputs to deal with the attendant diseases and disorders in an environmentally friendly manner in the near future.
Most SD onions derived from 'Grano' types suffer from short dormancy and thus tend to sprout within a few weeks after harvest, unless expensive control measures (CA and cold storage) are used. Breeding SD cultivars with inherited long-storage capacity will provide the optimal solution to reducing storage losses and costs. In recent years, attempts have been made in Brazil, India and Israel to develop high-quality SD long-keeping cultivars. Indeed, some of these perform better than traditional culti-vars, as well as outyielding the popular 'Grano', 'Granex' and 'Creole' types (Peters et al., 1994), thus cutting losses, increasing growers' incomes and providing a continuous supply at reasonable price at times when bulb onions cannot be grown due to climatic conditions (e.g. the monsoon period in Thailand).
Was this article helpful?