The design and testing of a cutter and feeder mechanism for the mechanical harvesting of lentils

Although lentil is a valuable source of protein for humans and its straw is a highly valued animal feed, its production in West Asia and North Africa (WANA) is limited due to harvesting difficulties, including uneven ripening, lodging, growing of pods close to the ground, and shattering of seeds and leaves at maturity. Existing mechanical harvesting systems cause excessive seed (up to 55%) and leaf losses. Harvesting is therefore still commonly done by hand, but manual labour is becoming increasingly scarce and expensive. The objective of this study was to design and test a cutter/feeder mechanism for mechanical harvesting of lentils. A self-propelled experimental harvester, which cuts and collects shoots without threshing, was developed for this purpose. Its performance was compared to hand harvesting, in rolled and unrolled fields, using a split plot design. Lentils with 22% moisture (wet basis) were harvested, and then threshed using a stationary thresher. The experimental harvester was operated at 5 km h(-1) and a cutting height of 59 mm above the ground. Shattering losses of seed and straw were not significantly different from that which occurred in hand harvesting (F-statistic F<1). Residue losses were those left in the stubble, representing 2% of the seed and 20% of the straw, which can be partially recovered by grazing. (C) 2004 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.