ガーナ国における野菜およびマメ類遺伝資源の調査と収集

The collaborative exploration for collecting vegetables and legumes was conducted from October 19 to November 11, 1993 with Plant Genetic Resources Unit, Crop Research Institute in Ghana. The itinerary and the route of exploration were shown in Table 1 and Fig. 1 and the number of collections of vegetables and legumes was shown in Table 2. Three hundred and sixteen seed samples and one tuber sample were collected and 305 seed samples were introduced into Japan. These were 13 eggplants, 59 garden-eggs, 12 Solanum spp., 39 chilli peppers, 90 okras, 30 cowpeas, 25 bambara ground nuts, 11 peanuts and 26 of other vegetables and legumes. Half of introduced seeds are preserved at the National Institute of Agrobilolgical Resources, and another half of seeds were sent to the curator of vegetables and legumes for preservation, characterization and propagation. National Research Institute of Vegetables, Ornamental Plants and Tea will characterize and propagate vegetable genetic resources

Tunnel dryer and pneumatic dryer performance evaluation to improve small-scale cassava processing in Tanzania

In sub-Saharan Africa, cassava is grown by smallholder farmers and is the principal source of calories for the local population. However, the short shelf life of cassava associated with poor infrastructure in the region results in significant postharvest losses. The expansion of small-scale cassava processing could reduce these losses, but the availability of drying equipment suitable for use in such operations is limited. The objective of this research was to contribute to the development of cassava dryers suitable for use by smallholder farmers. A tunnel dryer and a pneumatic dryer being operated in Tanzania were evaluated using mass and energy balance analysis. It was found that the energy efficiency of the tunnel dryer was 29% and of the pneumatic dryer 46%. For the tunnel dryer, most of the heat losses were through unsaturated exhaust air, while for the pneumatic dryer, most losses were through radiation and convection. Practical Applications: In this study, a tunnel dryer and a pneumatic dryer suitable for use by smallholder farmers were evaluated during processing centers' usual cassava drying operations. The sources and extent of heat losses were identified, and then guidelines developed on how to reduce such losses. For both dryer types, improvements to the thermal insulation used could reduce heat losses to the ambient. For the tunnel dryer, decreasing the air mass flow rate by 57% would help to minimize exhaust heat losses without producing condensation inside the unit. For the pneumatic dryer, air mass flow rate could be reduced by 9%, improving energy performance without having a negative impact on the pneumatic conveying of the product. Those two modifications would be easy to implement and represent a significant contribution to the development of small-scale cassava drying technology

Characteristics of Different Systems for the Solar Drying of Crops

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder, seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of complex interactions particular between the intensity and duration of solar energy, the prevailing ambient relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the design and operation of the solar dryer