• During cultivation

It is impossible to control the development of Pectobacterium carotovorum subsp. carotovorum once it is present in the tomato stem. A certain number of measures, often identical to those which can be used to control the black marrow, can however be employed (you can consult the sheet Pseudomonas corrugata ).

The first thing to do is to quickly eliminate diseased plants . It will also be advantageous to lower the humidity of the vegetation and to avoid as much as possible that the soil is too wet. We will therefore avoid irrigation by sprinkling; if it is not possible to proceed otherwise, such irrigations should be carried out in the morning rather than in the evening, so that the plants dry quickly during the day, bearing in mind that they may be particularly dangerous near the harvest, especially if the sprinkling is not well managed over time.

The shelter must be well ventilated to dry vegetation following nocturnal condensation or sprinkler irrigation.

Care should be taken not to work in the plots when the plants are wet: the risk of bacterial transmission by contact is then high.

We will remove the maximum amount of plant debris at harvest, and we will avoid burying them in the soil because P. carotovorum subsp. carotovorum is maintained there relatively well.

• Next crop

As this bacteriosis represents a non-negligible risk for future crops, producers will have every interest in implementing prophylactic measures to limit the installation and spread of this bacterium.

The crop rotations , implemented preventively to delay the onset of telluric pathogens, will limit the maintenance P. carotovorum subsp. carotovorum in the soil. The polyphagia of this bacterium limits the choice of species to cultivate. One will preferentially choose crops that are not very receptive or not, such as cereals, grasses or corn, soybeans or beans. The proximity of sensitive and / or already contaminated crops should be banned. Sensitive weeds should be removed.

Plots located in locations will be more readily used well-ventilated , favoring drying of the leaf blade. Whenever possible, we will choose to plant crops at a rather dry period of the year. The preparation of the ground must be particularly careful and will favor a good drainage of the latter. The manuring of the plants must be balanced, avoiding excess nitrogen. In soil-less cultivation, it will be advantageous to use a nutrient solution with a rather high potassium / nitrogen ratio. Culture conditions conducive to the appearance of wounds should be avoided.

The fruit harvest will occur before maturity , by dry weather and taking care to minimize injuries . The fruits will be quickly refrigerated or stored in a dry and cool place. We advise you to also consult the Recommended measures for post-harvest diseases .

Currently, there are no varieties commercially available tomato resistant to P. carotovorum subsp. carotovorum . Some lines have been described very occasionally in the literature as having fruits that are less sensitive to this bacterium. This tolerance would be polygenic in nature.