Do smallholder farmer-led seed systems have the capacity to supply good-quality, fungal-free sorghum seed?

Local seed systems that are developed, managed and maintained by farmers are a fundamental practice in smallholder crop production, supporting more than 80% of farmers in sub-Saharan Africa and feeding more than 70% of its population. The resilience of such systems is under threat from poverty, climate change, drought, increased pests and diseases, over-promotion of modern crop varieties, change of lifestyles and restrictive seed policies. The system continues to be maligned as having inferior quality, yet few studies support this assertion. This study aims to fll this research gap by evaluating 60 sorghum seed samples collected from smallholder farmers in Uzumba-MarambaPfungwe and Chimanimani districts of Zimbabwe. We investigated the efect of farmer-led seed management practices (e.g. seed acquisition and seed storage practices) on farm-derived sorghum seed quality (moisture, germination and fungal incidences). We found farmers using diverse seed sources and seed storage practices. Seeds were typically of good quality in that their storage moisture content was low, their germination was high, and fungal incidences were low. Seed sourced from local markets, non-governmental organizations and other farmers had germination and moisture standards that met the sorghum certifcation standards in Zimbabwe. However, few samples obtained from the relatives and government failed to meet the germination and/or moisture certifcation standards. We detected low incidences of fungi (Aspergillus favus, Aspergillus niger, Curvularia lunata, Fusarium sp. and Penicillium sp.) in sorghum seed samples tested and in particular Fusarium sp., which is the most economic important fungus in sorghum production. We conclude that farmer-led seed systems have the capacity to supply seeds of good quality and recommend that such systems should be recognized and promoted to meet the ever-evolving needs of smallholder farmers in sub-Saharan Africa

RE-CLASSIFICATION OF AGRO-ECOLOGICAL REGIONS OF ZIMBABWE IN CONFORMITY WITH CLIMATE VARIABILITY AND CHANGE

Zimbabwe was divided into five agro-ecological regions in the 196Os, however, the increased variability of rainfall has possibly affected the agro-ecological region boundaries. This study re-classifies the agro-ecological regions (natural regions) of Zimbabwe using soil data, mean-annual rainfall and length of growing season. Rainfall data from selected meteorological stations covered the period 1972- 2006. Soil data were obtained from the soil map of Zimbabwe, while length of growing seasons data were obtained from the FAO New Local Climate database. The simple limitation approach was used to produce a suitability zone map using all the parameters with the same weighting. The results show that the number of regions remained the same although the size of the regions had changed. The findings from this study point to an increase in the size of Natural Regions (NRs) I, IV and V by 106, 5.6 and 22.5 %, respectively. Natural Regions II and III decreased by 49 and 13.9%, respectively. The shrinking of Natural Regions II and III which are the main food producing areas in Zimbabwe, point to possible reduction in food production and thus problems of food insecurity. The shifting of the NRs boundaries observed in this study strongly points to evidence of climate variability and change.Le Zimbabwe \ue9tait subdivis\ue9 en cinq r\ue9gions agro \ue9cologiques dans les ann\ue9es 1960 ; par ailleurs, la variabilit\ue9 accrue des pr\ue9cipitations aurait affect\ue9 les limites des zones agro \ue9cologiques. Cette \ue9tude r\ue9-classifie les r\ue9gions agro \ue9cologiques (r\ue9gions naturelles) du Zimbabwe \ue0 l\u2019aide de donn\ue9es p\ue9dologiques, la moyenne des pr\ue9cipitations annuelles et la dur\ue9e de la saison des cultures. Les donn\ue9es des pr\ue9cipitations de stations m\ue9t\ue9orologiques s\ue9lectionn\ue9es couvraient la p\ue9riode 1972-2006. Les donn\ue9es p\ue9dologiques \ue9taient obtenues de la Nouvelle banque des donn\ue9es du climat Local de FAO. L\u2019approche de simple limitation \ue9tait utilis\ue9e pour produire une carte de zone d\u2019aptitude par l\u2019utilisation de tous les param\ue8tres avec la m\ueame pond\ue9ration. Les r\ue9sultats montrent que le nombre de r\ue9gions sont rest\ue9es les m\ueames bien que la superficie de ces r\ue9gions avait chang\ue9. Les r\ue9sultats de cette \ue9tude montrent une augmentation de la superficie des r\ue9gions naturelles I, IV et V par 106, 5.5 et 22.5%, respectivement. Le r\ue9tr\ue9cissement des r\ue9gions naturelles II et III qui sont des milieux principaux de production alimentaire au Zimbabwe, atteste une possible r\ue9duction de la production alimentaire et ainsi probl\ue8mes de l\u2019ins\ue9curit\ue9 alimentaire. Le changement observ\ue9 des limites des r\ue9gions naturelles dans cette \ue9tude est une preuve \ue9vidente du changement du climat et sa variabilit\ue9