Ink disease caused by the root-rot pathogen P. cinnamomi (Pc) threatens European sweet chestnut (Castanea sativa Mill.) orchards, and growers increasingly graft susceptible C. traditional varieties on Pc-resistant hybrid commercial rootstocks. The influence of scion, rootstock, grafting per se vegetative budburst, growth, susceptibility to Pc defence-related hormone profile Castanea spp. are un...