Influence of Altitudinal Gradients on Leaf Morphometric Traits of Chromolaena odorata (L.) Growing in Agroclimatic Zones of Karnataka, India

Abstract

This research was carried to assess the influence of altitudinal gradient on the leaf morphometric traits of C. odorata. Leaf morphometric traits such as leaf length, leaf width, petiole length, leaf shape and leaf colour were recorded.  The findings indicated notable differences in leaf length, leaf width, and petiole length across different altitudinal zones. Among the altitudinal zones the mean leaf length varied from 7.33 to 11.56 cm. The highest leaf length was observed in Zone-D followed by Zone-B and least in Zone-E. The mean leaf width displayed a range from 4.93 to 7.62 cm across the altitudinal zones. Zone-D showcased the greatest leaf width, followed by Zone-B, while Zone-E recorded the smallest leaf width. The altitudinal zones revealed a variation in mean petiole length from 1.74 to 3.11 cm. The highest petiole length was observed in Zone-D followed by Zone-B and least in Zone-E. Leaf shapes varied across altitudinal zones, spanning from ovate to lanceolate. Two colour shades of leaves were observed light green and dark green. Within the altitudinal zones, Zone-D demonstrated the highest values for leaf traits, followed by Zone-B, and the lowest values were observed in Zone-E. The findings indicated that Zone-D and Zone-B, characterized by hilly terrain, high altitude, and ample rainfall, exhibited higher values for the recorded parameters. Conversely, Zone-E, located in the North transition zone with high altitude but lower rainfall, showed limited growth. This study underscores the influence of physiographic and climatic conditions on the leaf morphometric traits of C. odorata.