Post Harvest Losses of Maize in Developing Countries

Quality deterioration of maize occurs mainly due to the adoption of improper techniques during post harvest operations such as harvesting, threshing, cleaning, drying and storage. Studies have shown that maize farmers often harvest their crops at incorrect stage of maturity and this leads to serious quantitative and qualitative losses. Early harvesting of maize is leads to incidence of high levels of immature, partially filled and unfilled grains. Such maize is not suitable for further processing and cannot be kept for a long period of time. Therefore, it is important that awareness is created among farmers on importance of harvesting at correct stage of maturity through effective farmer extensions programmes. Serious quantitative and qualitative losses are also encountered when the different types of methods that are used for threshing. The quantitative loss that occurs during threshing is caused by spillage and incomplete separation of grains from the cob. Another problem during threshing is contamination of grains with extraneous matter from the threshing floor. The separation techniques adopted at farm level to remove impurities from maize is inadequate at present. Most farmers use only winnowing techniques which remove only light impurities and heavy impurities such as sand and stones remain in the maize. Presence of sand and stones not only results in poor quality maize but also cause damage to processing machinery.  High quantitative and qualitative losses occur in maize when improper drying techniques are used due to fallowing reasons: spillage, consumption by birds, grain fissuring or cracking due to over drying, mould damage due to slow and inadequate drying especially during wet weather, and contamination of grains with extraneous matter. In addition to that serious post harvest losses are also occurred at all levels of storage of maize mainly due to lack of proper storage facilities and adoption of improper storage techniques by farmers, processors and traders. Creating awareness on improved cost effective post harvest techniques among large number of farmers is paramount importance in order to reduce the post harvest losses of maize.   

Maize