ABSTRACT

The operations involved in the crop production cycle include land clearing, land forming! land levelling, tillage, and crop establishment, harvesting and post-harvest operations. Crop establishment is necessary to eliminate the effect of weeds, pests and disease infestation and to provide suitable conditions for optimum yield. Weed control is one of the most difficult tasks in agriculture that accounts for a considerable share of the cost involved in agricultural production. Farmers generally expressed their concern for effective weed control measures to arrest the growth and propagation of weeds. The cost of weed management is enormous; however the opportunity cost of weed management is higher. Manual weeding is common in Nigerian agriculture. It is the most widely used weed control method but it is labour intensive. The use of mechanical weeder will reduce drudgery and ensure a comfortable posture of the farmer or operator during weeding. This will resultantly increase production. It is against this background that this project work was being carried out. Hence, the project involved the design, construction and development of a mechanical rotary power weeder. The weeder was designed based on different theories, assumptions, analysis and results being made. It was made up of majorly the frame, the power unit, propelling and cutting/weeding unit. Results of field performance evaluation carried out at the National Root Crop Research Institute Umudike Experimental field showed that the weeder had a theoretical field capacity of 0.079 ha/hr and an actual field capacity of 0.074 ha/hr. The weeding efficiency of the mechanical rotary power weeder was 73.4%, and the machine! field efficiency was 93.3%. The machine was found to be economically viable with fuel consumption limited to 7 litres per day. Clues on how to maintain the machine and some precautions to adhere to when operating the machine were outlined. Some recommendations towards increasing the weeding efficiency and the overall performance of the machine were also outlined.