1. A Summary

Historically and geographically most animal drawn implements have been devised for one major purpose. Wheeled toolcarriers are multipurpose implements that can be used for plowing, seeding, weeding and transport. Many have been designed as ride-on implements using a "bullock-tractor" analogy. Careful distinction should be made between these implements and the much lighter, cheaper and more successful "simple toolbars" without transport wheels.

Pioneering work was undertaken in Senegal in 1955 by the French agricultural engineer Jean Nolle who has since designed many wheeled toolcarriers including the Polyculteur and Tropicultor. The British National Institute of Agricultural Engineering (NIAE) produced a wheeled toolcarrier prototype in 1960 and several original designs were developed in India and Africa from 1960 to 1975. As a result of British and French technical cooperation, early toolcarriers were tested in many countries in the world. They were actively promoted with credit and subsidies in Senegal, Uganda, The Gambia and Botswana. In all countries they were conclusively rejected by farmers as multipurpose implements and mainly became used as simple carts.

In 1974 the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) started a major programme of research involving the use of wheeled toolcarriers in a crop cultivation system based on broadbeds. This resulted in the development and refinement of two main wheeled toolcarriers, the Tropicultor and Nikart. The cropping system was very effective in the deep black soils of the research station and was promoted in several states in India. It did not prove successful at village level. Up to 1200 toolcarriers were distributed to farmers through credit and subsidies of up to 80%, but they were rejected as multipurpose implements, and most now lie abandoned or are used as carts.

Encouraging reports of the on-station successes of wheeled toolcarriers increased during the 1970s and early 1980s and stimulated much wider international interest in the technology. Significant numbers of wheeled toolcarriers were imported into Mozambique, Angola and Ethiopia and smaller quantities were tested in Cameroon, Lesotho, Malawi, Mali, Niger, Nigeria, Somalia, Zambia, Zimbabwe and elsewhere. Large scale production was started in Brazil and Mexico, with smaller numbers produced in Honduras and Nicaragua.

To date about 10 000 wheeled toolcarriers of over 45 different designs have been made. Of these, the number ever used by farmers as multipurpose implements for sever-al years is negligible. The majority have been either abandoned or used as carts. Present prospects for these implements in Asia and Africa seem very poor. Recent initiatives in Latin America have not yet been fully evaluated, but already many of the reasons for the equipment being rejected in Africa and India have been cited as constraints in Latin America, and there is little reason for optimism.

Wheeled toolcarriers have been rejected because of their high cost, heavy weight, lack of manoeuvrability, inconvenience in operation, complication of adjustment and difficulty in changing between modes. By combining many operations into one machine they have increased risk and reduced flexibility compared with a range of single purpose implements. Their design has been a compromise between the many different requirements. In many cases for a similar (or lower) cost farmers can use single purpose plows, seeders, multipurpose cultivators and carts to achieve similar (or better) results with greater convenience and with less risk.

Farmer rejection has been apparent since the early 1960s, yet as recently as 1986 the majority of researchers, agriculturalists, planners and decision makers in national programmes, aid agencies and international centres were under the impression that wheeled toolcarriers were a highly successful technology. These impressions derive from encouraging and highly optimistic reports.

All wheeled toolcarriers developed have been proven competent and often highly effective under the optimal conditions of research stations. Most published reports derive from such experience and individuals and institutions have consistently selected the favourable information for dissemination. Published economic models have shown that the use of such implements is theoretically profitable, given many optimal assumptions relating to farm side and utilization patterns. In contrast there are virtually no publications available describing the actual problems experienced by farmers under conditions of environmental and economic reality.

The wheeled toolcarrier programmes have illustrated the dangers of research limited to research stations and domineering ("top-down") philosophies. They have also highlighted the problems of emphasizing technical efficiency rather than appropriateness, both to the needs of the farmers and to the realities of their environments. In future farmers should be involved (like consultants) at all stages of planning, implementing and evaluating programmes.

Most individuals and institutions are afraid of adverse public reaction if they report "failures". Attitudes must be changed so that disappointments are seen constructively as valuable "negative lessons". If the national programmes, the aid agencies and the international centres fail to accept this challenge, major opportunities for learning will be lost and more time and money will be wasted.

The wheeled toolcarrier story is remarkable, for the implements have been universally "successful" yet never adopted by farmers. If the lessons from this can lead to more realism in reporting, more appropriate programmes and more involvement of farmers, then the time and money spent may eventually be justified.