Agricultural Reviews

Harvesting and threshing operations contribute to overall post harvest losses. The speed of manual cutting operations risks significant crop losses due to delayed harvesting in developing countries. When harvest is delayed, shatter loss is the mostoften mentioned cause of losses. Estimates of harvest losses range from 5 to 16% for rice and 8 to 18% for a range of different cereal crops. All of the cereal, oilseed and pulse crops have a narrow range of moistures for optimally-low harvest losses and high crop quality. The optimal moisture for harvest of all crops isnearly alwaystoohigh to allow safestorage. Increased harvest mechanization can enable more timely harvest with lower losses, and would likely to create a gender shift in harvest workers. Training is essential for developing mechanized harvest operator skills. Most non-mechanized threshing systems have an inadequate means for separation and containment of harvested grains, oilseeds, and pulses. Threshing, separating and cleaning losses for well-trained combine operators can be very low, rice 0.3%, maize 0.4%, soybeans 0.75–1%, and wheat 1% of yield or less. Losses will go higher when the header is included but in general, rice should be less than 1.25–2.2%, maize less than 1.8%, soybeans less than 3%, and wheat less than 2% of yield in good standing crop.