A QUANTITATIVE EVALUATION OF GRASSHOPPER (ORTHOPTERA: ACRIDIDAE) DAMAGE AND ITS EFFECT ON SPRING WHEAT1

Autor: Mukerji, M. K., Pickford, R., Randell, R. L.
Zdroj: The Canadian Entomologist; March 1976, Vol. 108 Issue: 3 p255-270, 16p
Abstrakt: AbstractStudies were carried out to investigate the growth response of normal and defoliated spring wheat. Plant growth is expressed by the von Bertalanffy (1957) growth equation modified to allow for declining growth potential with age. Grasshopper damage was assessed by comparison with artificial defoliation and results indicated a simple linear relationship between grasshopper food consumption and defoliation damage. On the basis of this relationship it indicated that grasshoppers feeding on wheat waste 6.2 times as much foliage as they actually consume. Damage to foliage is translated into an effect on grain yield by an allometric relationship between total plant weight and yield. A simulation model indicating the time course of plant biomass provides realistic estimates except in the case of acute defoliation.
Databáze: Supplemental Index