In a developing country like Pakistan, post-harvest losses of citrus fruits are in the range of 23-38% as against 5-10% in developed citrus growing countries like Brazil, USA, Australia, Spain, Italy and Israel. Primary factors of post-harvest losses in citrus are mechanical, physiological, pathological or environmental factors are directly responsible. Mechanical loss is caused by careless handling during harvesting, packing, transportation, storage etc. Some insects and birds are also responsible for the mechanical injury. A significant portion of losses during post-harvest period is attributed to diseases caused by fungi and bacteria. Besides attacking fresh fruits and vegetables, these organisms also cause damage to canned and processed products. Environmental factors, temperature, humidity, composition and proportion of gases in controlled atmospheric storage also play an important role. High temperature and relative humidity favors the growth of micro-organisms which cause extensive damage to the produce.