Design and construction of a manually operated rotary paddy weeder for Busitema community.

Abstract

Rice is the world's most important cereal considering the area under cultivation and The number of households that depend on it. Rice farmers are encountering several constraints that inhibit their ability to increase rice production one of which is high crop damage and loss caused by weeds. Weed control methods such as. chemical and hand weeding are viable alternatives but the impact of the herbicides the environment arid their cost has made the method unsustainable whereas the hand weeding is tedious and time consuming. The design was done by first analysing the forces acting on the parts of the weeder, determining the dimensions of the parts and then selecting the proper material to use. Mechanical properties were considered during the selection of the materials. The cost and availability of the material on the market were also considered. Wood and steel in different grades were the major materials’ used. Engineering drawings of the components were done using AutoCAD on which the construction of the prototype was based using manufacturing methods like cutting, drilling, turning and welding. The components were then assembled by bolting and welding. The weeder was tested and found to be working well and its efficiency was found to be 79%. which is above average so it could provide yield advantage to the farmers by reducing the crop loss due to weeds. For the weeder to work effectively the rice has to be planted in rows and the fields have to be drained to 20mm depth of water.