ABSTRACT
This chapter reviews many aspects of crop protection and also storage in tropical conditions. Scientific information on onion growing in the tropics is limited and the existing sources of information come from widely scattered sources. Local breeding has also produced genotypes which yield well even in the humid tropical and coastal climate, but seed multiplication is carried out in the neighboring semi-arid areas. Yield varies with variety, season and cultural practices adopted, with ranges from 15 to 55 t/ha in different parts of the tropics. In the tropics, vernalization requirements are met by producing seed crops under the wider diurnal range in temperature found at latitudes of some distance from the equator, or in highland areas where cooler temperatures are found. A dry season crop is usually planted on the flat and a rainfed crop on raised beds. Suitable paths are allowed for carrying out of agrotechnical operations like spraying, weeding, fertilizing, and harvesting.
