Bacterial canker severity during the nursery stage is affected by fertigation

摘要

Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmiri) is an important disease of tomatoes. Seedlings supplied by nurseries may serve as a source of primary inoculum in commercial production units. In the nursery, infectionsoriginate from contaminated seeds, and the pathogen may also spread and develop during the nursery stage. In the nursery, seedlings are irrigated through overhead irrigation systems and fertilizers are incorporated in the irrigation water (fertigation).It was hypothesized that addition of fertilizer to the irrigation water influences the host-pathogen interactions and alters the development of the disease in the nursery. The specific goals of the research were to 1) study the effect of fertigation ondisease severity and 2) examine whether rinsing the foliage with fresh water soon after fertigation affects seedling infection. Results showed that even a single fertigation cycle prior to Cmm inoculation significantly increased disease severity as compared with seedlings that were not fertigated. The pH of the fertigation solution had no significant effect on disease severity. Rinsing with fresh water soon after fertigation decreased disease severity by ~75% compared with unrinsed plants.