Effect of Shade on Seedling Growth of <I>Grevillea robust, Tectona grandis</I> and <I>Ailanthus triphysa</I> in the Nursery

Abstract

An investigation on the effect of shade on growth of Tectona grandis, Grevillea robusta and Ailanthus triphysa seedlings were carried out at College of Forestry, Vellanikkara. The two levels of shades were full sun (0%) and 75% average shade. In Tectona grandis and Grevillea robusta seedlings the growth performance was better in full sunlight than in shade. The height, diameter, leaf area, leaf size, root weight, shoot weight, leaf weight and chlorophyll content were higher under full sunlight. On the other hand, Ailanthus triphysa seedlings performed well under shade. The growth in height, diameter, leaf area, leaf size, number, chlorophyll content, dry weight of shoot, roots and leaf were higher in shade than in full sunlight. From the present study it could be seen that the species are different with regard to their shade responses. Hence, it is necessary to screen the species based on their light requirements. This information could he used for commercial production of seedlings for extensive plantings under social and agroforestry programmes.