Leaf area and epicuticular wax content of Sida spp

Viviane Cristina Da Cunha,Karina Guimarães Ribeiro,Daniel Valadão Silva,Cintia Gonçalves Guimarães,José Barbosa Dos Santos,Germani Concenço,Roqueline Rodrigues Silva De Miranda

doi:10.1590/s0034-737x2014000200003

Abstract

Morpho-physiological characteristics and chemical composition are directly related to superior competitive ability of crops. This study intended to make a comparative analysis of dry matter production, leaf area and amount of epicuticular wax of three species of Sida spp: S. urens L., S. rhombifolia L. and S. spinosa L. Plants were collected at three growth stages: V1: stage described as up to 10 fully expanded leaves; V2: between 11 leaves and flowering; and R: after flowering. At stages V2 and R, the highest number of leaves was recorded for S. rhombifolia, followed by S. spinosa at V2 and S. urens at R. These results were relatively proportional to leaf area for all species. S. spinosa at the vegetative stage produced the highest values of specific leaf area (SLA), with no significant differences between species at the stage R. The amount of wax per unit of leaf area between species at the same developmental stage was significantly different only at the reproductive stage, where S. spinosa produced 23.18 and 6.23 fold more wax than S. urens and S. rhombifolia respectively. Between the growth stages of each species, there was decrease in the amount of wax with plant age and increase in leaf area (AFE), number of leaves and dry matter. The leaves of the Sida species exhibit different characteristics and this information can be used to optimize the use of herbicides in the control of these weeds.

Highlights

The genus Sida comprises more than 170 species and most of them are considered as potential weeds in pastures and annual crops
The highest leaf number was recorded at the vegetative stage V2 for Sida spinosa and reproductive stage R for the other species (Table 1). The influence of this variable in leaf area was evaluated at the final stage and produced similar results, e.g. more leaf area for S. rhombifolia, greater than 200 cm2, and 171.49 cm2 for S. urens
The highest specific leaf area (SLA) value for S. spinosa was recorded at the vegetative stage (Table 2)

Summary

Introduction

The genus Sida comprises more than 170 species and most of them are considered as potential weeds in pastures and annual crops. These species are widely distributed, hard to be controlled and adapted to weak and acid soils, they develop better in fertile clay soils (Kissmann & Groth, 2000). Several authors reported that morphological and physiological characteristics such as shoot, root and total dry mass (Wortmann, 1993; Olesen et al, 2004; Bianchi et al, 2006), plant height (Fleck, 1980; McDonald, 2003), leaf area (Wortmann, 1993; Lemerle et al, 1996) and leaf area index (Gibson et al 2003; Haefele et al, 2004) are directly related to superior competitive ability of crops. Over the past few years, research topics have been directed to the integrated weed management (Bianco et al, 2008) and providing relevant information to the evaluation of characteristics within a species that may interfere with the dynamics of control

Objectives

Methods

Results