An assessment of performance of soya bean (Glycine max) variety in low rainfall areas of Zimbabwe

Abstract Majority of small holder farmers in Zimbabwe are located in marginal rainfall areas where soils are sandy and less fertile. These farmers have been known to grow drought resistant varieties of maize, sorghum, pearl millet and finger millet in order to fight hunger and malnourishment. Due to environmental, ecological and other constraints, small holder farmers rarely produce surplus to generate income. Most farmers are now diverting from traditional crops into soya bean (Glycine max) production that is fetching lucrative prices on the market, despite being capital intensive as well as the harsh environments where the farmers are located. The farmers are often confronted with the problem of how to choose the best soya bean varieties suitable for their localities. The objective of this study was to apply the Randomised Complete Block Design to determine the best soya bean variety suitable for low rainfall areas in Zimbabwe. We investigated three major components namely germinability, survival rate and yield of five different soya bean varieties (Pan 891, Santa, Siesta, Serenade and Bimha) to assess their tolerance to low rainfall from the time of germination to the time of harvesting. Two-way analysis of variance was applied at 10 % level of significance to test for differences among the varieties with regard to the three components. Significant differences (p<0.10) were observed only in the yield component. Santa was ranked as the highest yielding variety, followed by Bimha, Serenade, Pan 891 and Siesta respectively. We therefore recommend Santa as the farmer's priority when purchasing soya been seed. In 1996, the National Soya beans Promotion Taskforce (NSPT) of Zimbabwe was formed to help increase the participation of small holder farmers in soya bean production in order to alleviate the problem of low nitrogen in communal soils (Rusike et al., 2000). Efforts to increase soya bean production, including efforts by the NSPT have been hampered by a number of constraints. Some of the constraints documented on small holder soya bean producers include use of unimproved varieties, unavailability of certified seed, use of retained seed and general lack of knowledge on recommended agronomic practices for soya beans (Shumba-Mnyulwa, 1996). In addition, poor plant population, inadequate plant protection, improper fertiliser application and poor adoption of post-harvest technology also contribute to low productivity of small and marginal farmers (Balasubramaniyan and Palaniappan, 2004) Among these constraints, the use of unimproved varieties has been identified as the major limiting factor least understood by small holder farmers. This has been attributed mainly to limited research and extension on soya beans in the small holder sector (Mabika and Mariga, 1996). The research therefore intends to provide a platform of using scientific research designs in order to determine best yielding varieties that will assist farmers in improving their crop yields.