Use of an Electric Nose and Dogs for In Situ Detection of White Root Rot Caused by Rosellinia necatrix

A commercial electric nose (e-nose Mobile (R)) and detection dogs were used to examine whether these can detect the infection of white root rot (Rosellinia necatrix) in situ or ex situ in pear orchards. The quality of odors was not different between the infected plots and the noninfected ones, but the odor intensity in the infected plots was significantly lower than in the un-infected control. For the plot of the infected rootlets exposed to the air in partly open, plastic baskets, the dogs succeeded to detect 89% after five days special training, and reached 100% success after 10 days training. But the dogs failed to detect the infected rootlets for the plot of potting with soil and infected rootlets, and for the plot of burying the infected rootlets into pear orchards in 15 cm soil depth. Overall, it seemed impossible to employ detection dogs as early detector of white root rot in pear orchards.