I_host: number of infected individuals for each cultivar and timestep
N_host: total number of individuals for each cultivar and timestep
Nhost: total number of cultivars considered in the simulation
Nyears: number of simulated cropping seasons
nTSpY: number of timesteps (e.g. days) per cropping season
severity_thresh: disease severity threshold above which the price reduction is applied
price_penalty: percentage of price reduction
Returns
A matrix with the price reduction rate per cultivar and per year of simulation
References
Savary, S., Delbac, L., Rochas, A., Taisant, G., & Willocquet, L. (2009). Analysis of nonlinear relationships in dual epidemics, and its application to the management of grapevine downy and powdery mildews. Phytopathology, 99(8), 930-942.