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Weeding out the best solution

The Teso region of north and eastern Uganda, an area that was once very productive, now struggles to improve crop yields despite the introduction of improved varieties. The culture of the Iteso people is closely linked to a tradition of animal rearing, predominantly cattle, sheep and goats and also to the use of draught animal power, but large numbers of animals were lost as a result of persistent raiding by the Karamajong warriors and rebels during the insurgency of the late 1980s and early 90s. Shortage in draught animal power (and human power from the AIDS epidemic)Oxen used for ploughing increases cultivation but also the need for weeding has resulted in less land being cultivated and the transformation of the area from a cash-crop to a subsistence economy. Furthermore, continuous cropping of smaller parcels of land closer to their homes has led to declining soil fertility and increasing pressure of weeds. And, as soil fertility has decreased, annual grass weeds and perennial weeds that are difficult to control have begun to build up and persist in some areas.

More recently oxen have been re-introduced in some areas to increase cultivated areas. But these increases have placed an additional labour burden on women and children, who are generally responsible for weeding by hand as few farmers can afford additional labour for weeding due to increased hire rates during peak periods. Weed pressure is seen by farmers as a major constraint to increasing production so in response to a needs assessment exercise, a project* based at the Serere Agricultural and Animal Research Institute (SAARI), identified a number of animal-drawn weeders which could be tested and evaluated by farmers. Two have performed well on-farm, have been well liked by farmers and have significantly reduced the labour costs required for weeding sorghum and groundnuts, both important crops for subsistence and cash income in the Teso Farming System.

Evaluating the equipment
The range of implements available to subsistence farmers for weeding and planting is generally limited so four different implements, which researchers felt would be appropriate, were put forward for evaluation. Two of the implements were developed by institutes of the National Agricultural Research Organisation (NARO), the SAARI and AEATRI weeders, whilst another, the SG2000, was imported from Kenya. A local plough was also put forward for evaluation by adapting it for weeding by removing the mouldboard, a technique widely used in Southern Africa but not previously tested in Uganda.

Farmers in seven different locations tested the ox-drawn weeders on sorghum and groundnuts during first and second rains. Experiences from the men and women involved in the trials were then shared with the researchers. Further participatory appraisal methods in nine locations allowed farmers to rank each of the weeders against a range of criteria e.g. removal of weeds, damage to crops, ease of transport and availability of spare parts. Interestingly, the weeder developed at the Agricultural Engineering and Appropriate Technology Research Institute (AEATRI) caused the most damage to crops, was the slowest to use and was least liked. In contrast, the local plough proved to be a cheap and effective implement. The locally developed SAARI weeder, bolted to the existing plough frame, also scored well as it was cheap to use and was effective at removing perennial grass weeds. And, although the SG2000 proved a fast and effective implement, spare parts were difficult to obtain.

Oxen used for ploughing increases cultivation but also the need for weeding
credit: Joel Wange

Technology takes off
Inevitably, some hand weeding still has to be done to remove plants in the crop rows but an overall reduction in the drudgery for women and children has been achieved and improved school attendance has been observed during the weeding seasons (May/June and October/November). With setting up demonstration plots with participating farmers, over 300 other farmers were trained in using the implements and further extension to 3-4000 farmers is planned as well as manufacture of weeding implements. Most importantly, for the majority of farmers who have access to oxen whether through ownership, hiring or borrowing, no capital investment is required as the local plough, without its mouldboard, can be used for weeding annual crops. It is unlikely, however, that this weeding technology will have an immediate impact on very poor households but it is hoped that as hire markets develop for draught-animal power, it is possible that this could become a cheaper option than hiring manual labour.

* 'Improving production in the Teso Farming System through the development of sustainable draught animal technologies' - a co-funded project by DFID's Livestock Production and Crop Protection research programmes, also involved researchers from University of Greenwich, UK; Serere Agricultural & Animal Research Institute, Uganda; Long Ashton Research Station, UK; and Silsoe Research Institute, UK.

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1st July 2003