A Thesis submittted in partial fulfilment of the requirements for the degree of Master of Enginee1ing

Thesis (M.Eng.) - Asian Institute of Technology, 1996

Pineapple plants, after the first harvesting, need to be dressed for good ratoon crop growth and for the healthy shoots for next planting. So far, pineapple plant dressing is done manually which is a very time consuming and back breaking job. To overcome this, a low cost pineapple plant dressing machine was developed. The developed machine was mounted at the front of the power tiller with an engine capacity of 8.6 kW. A special transmission mechanism was developed to transmit power from the engine to the rotary blades. At a time, the machine could dress two rows of pineapple plants. The rotational speed of the cutting blade was 533 to 800 rpm. The field tests were conducted at 1.21 to 1.74 km/hr forward speed. Some of the physical properties of a pineapple plant stem and leaves were investigated. The preliminary testing of the machine was carried out in a field with tall and strong grass. Based on the working problems of the first prototype the machine was modified. The second prototype was tested at the pineapple plantation site. The field testing showed that the developed machine could dress an area of 0.11 to 0.15 ha/hr. The average field efficiency and cutting efficiency were found to be 73.28 and 90.1 % respectively. The machine with the power tiller was capable of dressing over six to eight times the area covered manually. The estimated cost of dressing with the developed machine was $12.20/ha which is one-third of the cost of the traditional method. The performance and cost analysis of the machine indicates that considering the current labor shortage, the machine will have wider application for pineapple growers.