Next: Introduction
Predicting the Spread of Plant Disease: Analysis of an
Infinite-Dimensional Leslie Matrix Model for
Phytophthora infestans
James A. Powell1 and Ivan Slapnicar2
Department of
Mathematics and Statistics
Utah State University
Logan, Utah 84322-3900
USA
- Wopke van der Werf
Crop and Weed Ecology Group
Wageningen University
Bode 98, Postbus 430
6700 AK Wageningen
The Netherlands
Abstract:
A model for the size class distribution of plant disease on plant tissues
is developed, inspired by late blight lesions on potato and tomato caused by
Phytophthora infestans. In the absence of spatial dispersal the model
becomes an infinite-dimensional Leslie matrix, and when spatial dispersal is
considered several elements of the Leslie matrix are convolution operators
accounting for the spread of spores and generation of new lesions. The
maximum predicted speed at which lesions spread is calculated by extending
the method
of Neubert and Caswell [
15], which determines maximum possible front speed
for propagation of invasions of an age-structured population, to the case of
infinite-dimensional matrices. Observed speeds agree with predicted speeds to
within errors
resulting from convergence to the stable age distribution and to the
asymptotic front speed.
Keywords: Phytophthora, integrodifference
equations, Leslie matrices, fronts, invasion, rates of spread
AMS Subjects: 92D25, 92D99
Running Head: Spread of Plant Disease
Submitted to SIAM J. Applied Math
Next: Introduction
James Powell, Ivan Slapnicar and Wopke van der Werf
2002-06-01