Please cite this article in press as: Mammeri, Y., et al., How changes in the dynamic of crop susceptibility and cul- tural practices can be used to better control the spread of a fungal pathogen at the plot scale? Ecol. Model. (2014), http://dx.doi.org/10.1016/j.ecolmodel.2014.02.017 ARTICLE IN PRESS G Model ECOMOD-7156; No. of Pages 14 Ecological Modelling xxx (2014) xxx–xxx Contents lists available at ScienceDirect Ecological Modelling journa l h om epa ge: www.elsevier.com/locate/ecolmodel How changes in the dynamic of crop susceptibility and cultural practices can be used to better control the spread of a fungal pathogen at the plot scale? Y. Mammeri a,∗ , J.B. Burie b , M. Langlais b , A. Calonnec c,d a LAMFA – CNRS UMR 7352, Université de Picardie Jules Verne, 80039 Amiens, France b UMR CNRS 5251 IMB, Université de Bordeaux, 3 ter Place de la Victoire, 33076 Bordeaux, France c INRA, UMR1065 SAVE, 33883 Villenave d’Ornon, France d Université de Bordeaux, ISVV, UMR SAVE, 33883 Villenave d’Ornon, France a r t i c l e i n f o Article history: Available online xxx Keywords: Plant-pathogen Heterogeneous plot PDE–ODE Simulations Treatments a b s t r a c t A PDEs–ODEs model was developed to describe the spread of an airborne fungal pathogen on grapevine. The model was able to retrieve the main characteristics of the system: (1) a host growing during the whole season with time evolution in susceptibility, (2) a crop highly structured in rows with potential heterogeneities of plant growth and susceptibility within and between plots. These characteristics are modified by cultural management. Simulations were performed to test the effect of crop spatial hetero- geneities, within and between plots, on the disease spread. Heterogeneities considered were the plant growth (vigour, earliness), susceptibility (susceptible vs resistant, treated vs untreated) and the spatial arrangements (patches vs rows). The main effect on disease reduction was obtained by arrangement in rows of susceptible and fully resistant plants. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The high success of controlling plant pathogens through pes- ticide applications has limited the amount of attention paid to influence of cultural practices or alternative control methods. How- ever, over the past 30 years, strategies for crop protection relying on the use of pesticides have generated complex and controversial issues both concerning the human health and on the environ- ment. Growers are now constrained to significantly reduce the use of fungicides by European directives on the sustainable use and their registration (Directive 1107/2009/EU). Also the French government currently enforces a national action plan for pesticide reduction (the Ecophyto 2018 plan) which aims at halving pesticide use over a 10-year period. Consequently, low-pesticide systems based on the development of innovative control methods need to be developed and their performance to be evaluated (Andrivon et al., 2013). One of these control methods could rely on mod- ification of plant growth and architecture by using architectural diversity and cultural practices. Evidences of epidemic variations attributed to modifications of canopy porosity and susceptibility in ∗ Corresponding author. E-mail address: youcef.mammeri@u-picardie.fr (Y. Mammeri). main pathosystems and on their effects on pathogen processes such as infection and dispersion have recently been reviewed (Calonnec et al., 2013). Spatial heterogeneity can be generated, at the plant, plot and landscape levels with changes over time. However, setting up and implementing such alternatives in sustainable agriculture requires research to develop models able to explore hypotheses on their functioning and to test cropping systems that could be used to control and reduce disease spread. Simulations allow gen- erating plots or patches within plots which differ in phenology, growth rate, crop management and training system for various cli- matic scenarii which can differently impact plant and pathogen growth. The effects of individual plant and crop heterogeneities on pathogen or disease spread have rarely been explicitly taken into account in epidemiological models. However, the influence of spatial heterogeneities on the spread of a biological invasion has been investigated both theoretically and through model sim- ulations (Hastings et al., 2005). The models involved are spatially explicit simulation models, integrodifference equations (Kot et al., 1996), and reaction-diffusion equations. The influence of hetero- geneities is taken into account by determining conditions for a successful invasion and by estimating spreading speeds. Spatial heterogeneity was introduced into a reaction-diffusion on a peri- odic mono dimensional domain with alternating favourable and unfavourable patches (Shigesada et al., 1986). The authors showed http://dx.doi.org/10.1016/j.ecolmodel.2014.02.017 0304-3800/© 2014 Elsevier B.V. All rights reserved.