Plants were monitored daily for 15 days to follow pathogen establishment and development of disease symptoms. The disease severity (DS) was evaluated following the scale described by Fery and Dukes (2002) (that is, 1 = no wilting symptoms, 2 = slight or partial wilting, 3 = general plant wilting, 4 = permanent wilt, and 5 = dead plant). Then, the disease severity index (DSI) was estimated on the basis of this rating scale by adopting the following formula