Bayesian correlated models for assessing the 1 prevalence of viruses in organic and 2 non-organic agroecosystems 3

Elena Lázaro, Carmen Armero, Luis Rubio
6 7 Virus diseases constitute one of the most important limiting factors in horticultural pro-8 duction. Cultivation of horticultural species under organic management has increased in 9 importance in recent years. However, the sustainability of this new production method 10 needs to be supported by scientific research, especially in the field of virology. We 11 studied the prevalence of three important virus diseases in agroecosystems with regard 12 to its management system: organic versus
more » ... organic versus non-organic, with and without greenhouse. 13 Prevalence was assessed by means of a Bayesian correlated binary model which con-14 nects the risk of infection of each virus within the same plot and was defined in terms of 15 a logit generalized linear mixed model (GLMM). Model robustness was checked through 16 a sensitivity analysis based on different hyperprior scenarios. Inferential results were 17 examined in terms of changes in the marginal posterior distributions, both for fixed and 18 for random effects, through the Hellinger distance and a derived measure of sensitivity. 19 Statistical results suggested that organic systems show lower or similar prevalence than 20 non-organic ones in both single and multiple infections as well as the relevance of the 21 prior specification of the random effects in the inferential process. 22 23