LAND SUITABILITY ASSESSMENT FOR CHERIMOYA IN SOUTHERN ECUADOR USING EXPERT KNOWLEDGE AND GIS

Cherimoya (Annona cherimola Mill.), a wild fruit-tree growing under sp ecific physical land conditions in southern Ecuador, has a distinct ec onomic potential. Its natural occurrence in southern Ecuador is largel y restricted to locations within the 1500-2200 m altitude range. In th is study, an attempt has been made to assess the suitability of land t o grow cherimoya in the province of Loja. Attributes of the physical e nvironment, based on expert knowledge from various regions growing che rimoya, were collected and used for the suitability assessment. Each a ttribute (rainfall, Koppens' climatic classification, altitude, soil t ype and ecotype) was mapped with the help of a GIS and classified on t he basis of predefined growth requirements. Climatic and soil requirem ents for cherimoya growth were identified and a land suitability map w as produced by overlaying the climatic and soil suitability maps. The climatic suitability map reveals suitable regions within the 1500-2200 m altitude range, where favourable temperature conditions prevail. Ab out 24% of the study area is found to be suitable for cherimoya growth , but only 2% is highly suitable. The most suitable areas are found in the south-east of the province. In the rest of the province climatic or chemical soil fertility conditions are expected to restrict cherimo ya growth. The results of this study can be used for further research on the possibilities for a large-scale commercialisation of the crop i n southern Ecuador and in other regions with favourable ecological con ditions. (C) 1998 Elsevier Science B.V. All rights reserved.