Evaluation of weed control methods for Small Scale Farmers in the production of Rainfed Wheat ( Triticum aestivum L.)

Abstract

On-farm experiments were conducted in the 1992-93 cropping season at Kasisi and Mufubushi. The objective of the experiment was to test alternative weeding methods to the present use of the hand hoe, for weeding in rain fed wheat production in Zambia. Six weed control treatments were used and included use of the hand hoe (farmers practice), the dutch hoe, the weed wiper and the ox-drawn cultivator as well as clean and no weeding as controls. Weeding in the treatments was done once, except in the clean weeding treatment. A high weed infestation after weed control was observed at Kasisi. None of the weed control methods performed well in reducing weed re-infestation. Grain yield of rain fed wheat at Kasisi was very poor(38kg/ha average) and was observed not to be negatively correlated with weeds. Negative economic returns were observed in all selected weed control methods. According to the results of the partial budget for Kasisi, the dutch hoe, weed wiper and ox-drawn cultivator had lower weeding cost compared to hand hoe weeding, thus being a potential alternative to the hand hoe. Kasisi seems to be agro-ecologically not suitable for rain fed wheat. Results of the experiments at Mufubushi showed that weeds were contributing to a reduction in grain yield of rain fed wheat. Nicandra physalodes, particularly, was observed to reduce grain yield. All selected weed control methods resulted in good yields (1577kg/ ha average) and economic returns ( K193,200/ha average). The use of the hand hoe at Mufubushi was observed to perform better than any other weed control method in terms of reducing weed competition and increasing grain yield. The hand hoe weeding also had the highest economic returns (K174,000/ha). However, it had the highest weeding cost (K54,000/ha) due to labour input cost( K51,300/ha). According to the results, the weed wiper and the ox-drawn cultivator weeding methods, despite their lower economic returns, had the lowest weeding cost (K 25,000/ha and K 15,000/ha, respectively). This makes them potential alternatives to the use of hand hoe.