Growth and chlorophyll indices in seedlings of Calotropis procera (Aiton) W. T. Aiton submitted to different levels of shading

Abstract

Several abiotic factors may influence the growth and development of forest species. Among these, luminosity is one of the most important, because it affects plant physiological processes and control their metabolism. The objective of this study was to evaluate the effect of different shading levels under growth and chlorophyll indices on Calotropis procera plants. The experiment was conducted in a greenhouse in a completely randomized design with 5 treatments (0, 30, 50, 70 and 90% of shading), 8 replicates and one plant per plot. Growth characteristics (leaf area, leaf area index, specific leaf area, leaf area ratio and leaf specific weight) and chlorophyll a, b, total index and chlorophyll a/b ratio were evaluated. The data were submitted to analysis of variance by the F test and in the cases of significance a linear and polynomial regression analysis was performed. Shade levels in the 40% range provide higher leaf area and leaf area index in silk flower plants. The specific leaf area and the leaf area ratio are positively influenced by shading. In shaded environments silk flower plants have reduced chlorophyll indices.

Keywords

• Silk flower. Luminosity. Photosynthetic pigments.