ABSTRACT
This chapter reviews onion storage diseases and there are several publications and other onion pathogens. Bulb onions are a widely distributed and important food vegetable consumed in most areas of the world. The onion is used mainly as a vegetable, but has had other roles in religion and medicine in a history. Onions from temperate regions have been distributed worldwide by the migrations of European man. The identification of infection sources of onion neck rot has been a major constraint to progress in the understanding of the biology of the pathogen. Information on the chemical nature of resistance indicates that in the dry skins of coloured onion bulbs this may be related to the presence of the phenol protocatechuic acid and catechol. Simple remedies can be effective with some of the diseases, seed treatment control of onion neck rot. Most bacteria producing post-harvest rots of onions are opportunist organisms; some are primary pathogens and others secondary, insect, or nematode attack.
