This preliminary study examined how two resources (light and nutrients) influence the ability of tomato plants to show growth compensation for defoliation by the tobacco homworm (Manduca sexta). Growth rate and biomass of plants grown under high and low levels of light and nutrients, and exposed to 4 levels of defoliation by Manduca sexta were measured. Nutrients affected plant growth rate much more strongly than did light. Light and nutrients, however, each influenced how herbivory affected plant growth. Defoliation significantly decreased growth rate only under conditions of low light and high nutrients. Biomass, on the other hand. was low under all resource treatments except high levels of both light and nutrients, and defoliation significantly decreased biomass only under high levels of both resources. Thus, plants appeared to compensate for damage. in terms of biomass, only under conditions of either low light and/or low nutrients.
Gertz, Anita K. and Bach, Catherine E.
"Effects of Light and Nutrients on Tomato Plant Compensation for Herbivory by Manduca Sexta (Lepidoptera: Sphingidae),"
The Great Lakes Entomologist, vol 27
Available at: https://scholar.valpo.edu/tgle/vol27/iss4/5