Effect of artificial defoliation on growth and biomass of Lantana camara L. (Verbenaceae)
Sonya BroughtonA, Department of Zoology and Entomology, The University of Queensland, St. Lucia, Queensland 4072, Australia.
A Present address: Entomology Department, Department of Agriculture Western Australia, 3 Baron-Hay Court, South Perth, Western Australia 6151, Australia.
Artificial defoliation techniques were used to examine the effect of frequency, timing and level of defoliation on Lantana camara L. (lantana). Every three months (spring, summer, or autumn), 0%, 50% or 100% of leaves were removed from plants. Changes in plant height, stem width and the number of stems were recorded one month after each episode of defoliation. At the end of the experiment all plants were harvested and the amount of biomass (dry weight) was calculated for the stems, roots, leaves and reproductive structures (buds, flowers and fruit).
There were no significant decreases in vertical height or the number of stems produced, but plants defoliated in spring produced more stems than those defoliated in spring and again in autumn. Similarly, there were no differences in root, stem, leaf or reproductive structure biomass. However, differences in the proportion of biomass allocated to reproduction were recorded. Plants that had been defoliated three times allocated a higher proportion of their biomass to reproduction than those defoliated once or twice. Overall, these results suggest that lantana compensates for defoliation.
Plant Protection Quarterly (2003) 18 (3) 110-115.