Design and construction of a tractor drawn sweet potato harvesting implement.

Abstract

Sweet potato (ipomoea batatas Lamk), a South America crop by origin (Austine 1988) and introduced by missionaries in Uganda in 1900s, is one of the most important crops in densely populated East African countries and is a major staple in Uganda. It’s grown through-out the country as a subsistence food crop however major production areas include north eastern and south western regions of Uganda. It's considered a priority crop and its importance has increased significantly over the years. It's an important food and cash crop especially in highland areas like Kabale and food security crop consumed when there is shortage of major staple foods. Some of the challenges by sweet potato farmers are inadequate disease free planting material, quality reduction of planting after a few years, inadequate crop market, crop pests like weevils, butterflies, droughts. But the most factor constraining production is high labor and transport costs. This is due to less people getting involved ill crop production field activities as they are perceived as woman's activities, use of rudimentary tools in growing of crop like sticks and hand hoes in vine planting, checking on ready crops and crop harvesting which makes production labor intensive and time wasting. As a solution to sweet potato harvesting problem faced by farmers in Uganda, this project is geared to development of a tractor drawn sweet potato harvesting implement. his project was meant to design and construct a tractor drawn sweet notate harvesting implement. 10 achieve the design and construction of the crop harvesting implement, analysis of forces in the machine components under loading conditions like soli resistive forces were done to acquire the dimensions of machine parts. During fabrication, the researcher used different machine component production technologies like welding, marking, cutting, bending, drilling, grinding, and machining after which components were assembled together to form an implement. The implement was tested in the field using 11horse power tractor on two ridge parts, one was 3.58m and the second was 3.4 m long but both were 0.42m wide. Test parameters were percentage damage done on dug potatoes, implement digging rate, digging efficiency and the field capacity. For the 3.58m long ridge, the operating speed, percentage damage, digging rate, digging efficiency and field capacity were 3.22 km/hr, 38.9%, 2.25kg/s,60% and 0.031 ha/hr respectively and for 3.4m long ridge the operating speed, percentage damage, digging rate, digging efficiency and field capacity were 2.04 km/hr, 20%, 1.25kg/s, 45.4% and 0.025 ha/hr respectively.