Jose

PERFORMANCE EVALUATION OF THE TEK MECHANICAL CASSAVA HARVESTER IN THREE SELECTED LOCATIONS OF GHANA

by

Shadrack Kwadwo Amponsah BSc. Agricultural Engineering

A Thesis submitted to the Department of Agricultural Engineering, Kwame Nkrumah University of Science and Technology, Kumasi in partial fulfillment of the requirement for the degree of

MASTER OF SCIENCE (Agricultural MachineryEngineering)

College of Engineering School of Graduate Studies,

August, 2011

DECLARATION I, AMPONSAH SHADRACK KWADWO, author of this thesis titled “Performance Evaluation of the TEK Mechanical Cassava Harvester”, do hereby declare that apart from the references of other people‟s work which have been duly acknowledged, the research work presented in this thesis was done entirely by me inthe Department of Agricultural Engineering, Kwame Nkrumah University of Science and Technology, from August 2009 to August 2011. This work has never been presented in whole or in part for any other degree in this university or elsewhere.

Amponsah Shadrack Kwadwo (PG3768309) (Student and ID Number)

............................ Signature

....……………. Date

Certified by: Dr. E.Y.H. Bobobee(Supervisor) .………………… Signature .......................... Date

Prof. Ebenezer Mensah (Head of Department)

………………..... Signature

..............……….. Date

ii

ABSTRACT Cassava (Manihot esculenta Crantz) is the world‟s third most important crop and an essential source of food and income throughout the tropics providing livelihood for over 500 million farmers and countless processors andtraders. In Ghana, cassava contributes 22% of Agricultural Gross Domestic Product (AGDP) and is an emerging profitable industry crop. Large–scale cassava harvesting especially during the dry season is the greatest constraint to meeting its industrial demand through commercial production. Manual harvesting is slow and associated with drudgery and high root damage in the dry season. A mechanicalharvester is needed to break the labour bottleneck associated with cassava harvesting. Research on mechanization of cassava production, however is very low especially in the area of harvesting and currently there exists no known mechanical cassava harvesters in Ghana. The main objective of this study was to test and evaluate mechanical cassava harvesters for three (3) agroecological zones in Ghana.Performance of six (6) prototype mechanical harvesters (TEK MCH 1 to 6) was evaluated against various manual harvesting methods for five (5) cassava varieties on ridged and flat landforms. Results from field trials of the harvesters showed that the best performance was achieved on ridged landforms, which have better tuber yields and spread both across and along the ridge. „Nkabom’ cassava varietyon ridges gave the lowest average tuber damage of 9.91% when harvested mechanically. The mechanical harvesters worked best on ridged fields with minimal trash or weeds and relatively dry soils with moisture content from 1.0 – 16.0 % d.b, penetration resistance between 1.0 MPa and 3.99 MPa with bulk density from 1.56 - 1.68 g/cm3 and drafts of up to 12.3 kN, requiring a minimum tractor engine powerof 40.4 kW (54 hp) with penetration depth from 20.7 cm to 30.1 cm. The best harvesting performance was achieved at tractor speeds of 4 - 7 km/h giving a field capacity of 1.55 - 2.96 h/ha. After mechanical harvesting, the field is left ploughed with savings on fuel, time and cost for the next season. It is however recommended to test the harvesters in other agro-ecological zones under a wide rangeof soil moisture regimes in Ghana to promote nationwide adoption.

iii

DEDICATION I dedicate this project to the Almighty “I am that I am” God for his guidance and directions. I am nothing without you Lord! And to my dear dad, Mr. Patrick Freeman Osei for his support, prayers and encouragement and to my son, Emmanuel Marvin Osei Amponsah for bringing to me and my wife great joy and...