Cassava diversity in Ghanaian farming systems

Summary

The diversity of cassava was studied in 10 communities spanning a range of socio-economic circumstances and located in the four main agro-ecological zones in Ghana. On average, each farmer grew about two cultivars, mostly landraces, both for home consumption and sale of the storage roots. In total, 35 differently-named landraces were mentioned, 26 in only single communities. Most communities had grown cassava for > 100 years and seem to have acquired an additional landrace about every decade. Landraces were also abandoned. The attributes mentioned of newly-acquired landraces were generally the reverse of landraces abandoned and most were related to the storage roots. All the current landraces in all the communities seem to have been obtained from other communities. None of the almost 300 interviewed farmers understood the role of pollination in setting seed and providing variation amongst seedlings, none purposely planted seeds and most farmers ignored or weeded out cassava seedlings. However, some did use planting material (stem cuttings) from self-sown seedlings, often when planting material from their crops was scarce, and some purposely grew cuttings from a few such seedlings, apparently as experiments. That many seedlings were both reported and seen in newly-planted crops suggests that some may be accidentally used as planting material, especially those seedlings that are perceptually indistinct from the planted crop, resulting in polyclonal landraces.