Tree species yielding edible fruit in the coffee-based homegardens of Kerala, India: their diversity, uses and management

Abstract

The homegardens of Kerala are known for the high diversity of their species in both cultivated and managed plant communities, with fruit trees as one of the more important components. A study was conducted to quantify the density and diversity of both cultivated and non-crop trees that yielded edible fruit (hereafter, fruit trees) in coffee-based homegardens of the State. Among 101 species of fruit trees from 25 homegardens, 46 were cultivated and the rest were non-crop species. Cluster analysis of their relative density differentiated three clusters (Homegarden Types) which demonstrated variation in their structural characteristics. Tree density, Shannon index of diversity and evenness index in Homegarden Type 1 were significantly higher (P < 0.05) than in Homegarden Types 2 and 3. In the study area, the non-crop species most preferred for their fruits included Baccaurea courtallensis, Carissa carandus, Chrysophyllum roxburghii, Feronia elephantum, Flacourtia montana, Garcinia xanthochymus, Madhuca indica, Madhuca longifolia, Mimusops elengi, Zizyphus mauritiana and Zizyphus rugosa. Collection of fruits of cultivated species is primarily by special collection trips, whereas that of non-crop species is generally during casual visits by adults and children. In the study area, cultivated species were actively managed (eg. weeding, fertiliser application and pruning of branches) but for non-crop species management was relatively passive (toleration and protection). Contrary to the general fear at the global level that homegardens are losing their traditional characteristics and are being transformed into species-poor, cash-crop production systems, the homegardens of the present study are examples in which many traditional ecological features are being maintained. Recommendations, drawn from the results, for enhancing the economic value of homegardens and ensuring food security include tree improvement, domestication and sustainable cultivation of non-crop fruit trees in order to conserve diversity.