Abstract

Characters such as crown architecture, growth, leaf phenology and branching pattern were studied in 9 forest trees (Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Grewia tiliifolia, Macaranga peltata, Mangifera indica, Tectona grandisTerminalia paniculata and Xylia xylocarpa) growing in home gardens in Panancherry Panchayat, Kerala, with a view to assessing their suitability as components in home garden agroforestry systems. The species were classified using the architectural modelsof Halle, F. et al. (Tropical trees and forests: an architectural analysis (1978) New York, USA; Springer Verlag). Albizia and Xylia fell under the Troll model, while Grewia and Ailanthus came under the Roux and Koriba models, respectively. Mangifera andTerminalia grown under the shade and in the open exhibited different architectural models - Scarrone under shade and Leeuwenberg in the open. Artocarpus, Macaranga and Tectona conformed to the Rauh model. Albizia, Grewia and Xylia showed a low and dome shaped crown under shade, in contrast to a narrow and conical crown in the open. Conversely, Artocarpus, Macaranga, Mangifera, Tectona and Terminalia had a tendency to develop wider crowns in the open and narrow and conical crowns under shade. These characteristics are relevant to agrisilvicultural systems in which more shade demanding components are used. The study indicates that Albizia, Grewia and Xylia could be introduced in the early stages of perennial crop establishment as these trees are tendto grow straight with a narrow conical crown under less shade. In the case of Artocarpus, Mangifera, Tectona and Terminalia orthotropy enhances production of straight timber, but in the early stages of establishment of polyculture agroforestry systems these species may not be suitable as they tend to develop wider crowns in relatively open areas. However, when introduced into established agroforestry systems these species may produce straight timber and less crown spread. The study also indicated that foliage phenology is important in determining the appropriate crop mixture. Some of the species, such as Tectona, Macaranga, Xylia, Terminalia and Grewia, are deciduous in nature and leafless for 3-4 months, and there is scope for cultivating light demanding short-duration crops under such trees