The study assesses potential connection between flea beetle feeding and blackleg infection. The study also investigates whether controlling flea beetles with foliar insecticide, using a resistant cultivar and protecting seedlings with a fungicide seed treatment can alleviate the blackleg infection under different flea beetle feeding pressure.
Under controlled conditions without added moisture, cotyledons were given mechanical wounds and then exposed to the pathogen at various times – zero, two, four, eight, 12 and 24 hours – post wounding. Wounds older than eight hours showed much lower disease incidence than younger wounds, and the pattern was similar on both susceptible and resistant cultivars. This shows that L. maculans infects through fresh wounds more readily than through older wounds or intact cotyledons when there is a lack of leaf-surface wetness. Field trial data are still being analyzed.