Abstract

To evaluate the factors affecting the growth characteristics of Phalaenopsis leaves, the leaf-length growth patterns of two Phalaenopsis varieties, the red-flower Phalaenopsis clones ‘LB9506’ and ‘LB9508’, were measured under different environment condition such as day temperature, light intensity, and fertilizer rates. The fitting-agreement of three nonlinear growth equations was compared for evaluating leaf-length data for two varieties. The parameters of the adequate equation then were further studied. The results indicated the logistic equation was the best equation for describing the relationship between leaf-length and culture days. The parameters of this equation could be interpreted biologically. Environmental conditions and fertilizer rates had a significant effect on the maximal leaf-length for two varieties. The growth rate of one variety, ‘LB9506’, was influenced significantly by day temperature and light intensity. However, the growth rate of the other variety, ‘LB9508’, was not affected. As the plant growth data were fitted with the nonlinear growth equations and the parameters analyzed, it was discovered that this method was useful in studying the factors affecting Phalaenopsis leaf growth characteristics.

Key words: Growth equation, nonlinear regression, Phalaenopsis.