GROWTH AND ARCHITECTURAL ANALYSES OF TREES OF AGROFORESTRY IMPORTANCE IN KERALA

摘要

Characters such as crown architecture, growth and branch display were studied in nine forest trees namely Ailanthus triphysa. Albizia odoratissima, Artocarpus hirsutus, Grewia tiliifolia, Macaranga pettata, Mangifera indica, Tectona grandis, Terminalia paniculata and Xylia xylocarpa grown in homegardens of Panancherry Panchayat, Kerala, with a view to assess their suitability as components in homegarden agroforestry systems. Among these Albizia and Xylia fall under Troll model, while Grewia and Ailanthus come under Roux and Koriba models, respectively, Mangifera and Terminalia grown under the shade and in the open exhibited different architectural models namely Scarrone under shade and Leeuwenberg in the open. Artocarpus, Macaranga and Tectona conform Rauh model. Albizia, Grewia and Xylia showed the low and dome shaped crown under the shade in contrast to a narrow and conical crown in the open. On the other hand, Artocarpus, Macaranga, Mangifera, Tectona and Terminalia have the tendency to developwider crown in the open in contrast to a narrow and conical crown under shade. The growth and architectural characteristics of all these species have relevance especially in agrisilvicultural systems in which more shade demanding components are used. Thestudy reveals that Albizia, Grewia and Xylia could be introduced in the early stages of perennial crop establishment as these trees are having the tendency to grow straight with a narrow conical crown under less shade. Whereas, in the early stages of establishment of polyculture agroforestry systems, Artocarpus, Mangifera, Tectona and Terminalia may not be suitable as they have the tendency to develop wider crown in relatively open area. However, these trees when introduced in the established agroforestry system may produce straight timber and less crown spread. The study also indicated that foliage phenology is also important in deciding 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. There is scope for cultivating light demanding short duration crops under such trees.