Brown rot found in Dutch eggplant greenhouse
It's the first time that Ralstonia has been found in a Dutch eggplant cultivation. The source of the outbreak is still unknown, but tracing back activities are ongoing. In the upcoming weeks water samples of the adjacent waterway will be taken.
The finding was triggered following observation of symptoms. Some stems showed a brown discoloration of the vessels. The plants were tested at a private laboratory, which informed the Netherlands Food and Consumer Product Safety (NVWA) on May 18, 2016. The identity was confirmed on June 27, 2016 and the NVWA sent out a pest report this week.
Ralstonia solanacearum is listed as a harmful organism in the EU directive, so all plants with symptoms and their substrate are destroyed. The plants are grown in rockwool which is placed on a plastic cover on the soil.
In the greenhouse only plants for the production of Solanum melongena fruits are cultivated. In one part another variety was cultivated, which did not show any symptoms. The fruits of these plants can be harvested, but may not be sorted or packed at other production sites. Specific hygiene measures are imposed on the infested company for staff, equipment, storage containers and soil. The neighboring plants and their substrate on either side will be destroyed in the coming weeks to avoid contamination.
Ralstonia
Ralstonia solanacearum is the causal agent of the disease known as potato brown rot or bacterial wilt. The bacterium affects more than 30 plant species, the most susceptible crops being potato, tomato, eggplant, pepper, banana and groundnut.
Roses
In 2015, 13 Dutch rose companies (9 growers of cut roses and 4 plant growers/breeders) were contaminated with the brown rot bacterium Ralstonia solanacearum. By the end of 2015 NVWA decided, as a precaution, to extend the investigation to all growers of cut roses. In January/February 2016 no further spread of contaminated companies was noted. This outbreak isn't related to the outbreak in the eggplant cultivation.