Protection methods

Like many bacterial blight in plants, fire blight is very difficult to control. Its control will require the harmonious implementation of all the measures recommended thereafter.

• During cultivation

When the first spots of Pseudomonas syringae pv. aptata are observed in a piece of melon, it is unfortunately too late to intervene effectively: we do not have very effective measures to prevent the development of this bacteriosis.

We are still relatively powerless to control bacterial diseases using chemical agents. The copper * in the form of salts can be used to limit its extension: copper, copper sulfate ( e-phy ). It only has a preventive effect on the surface of the aerial organs. In the case of melon, copper should be used with caution, because it is a product which can be phytotoxic under certain conditions: when the concentrations used are high, when the temperatures during the treatments are too low or high . You must be particularly vigilant when using it on young plants.

In addition to copper treatments, we can also recommend reducing sprinkling irrigations to their strict minimum and carrying them out during the day, at a time when the plants will recover quickly.

In addition, it is advisable to work and circulate in the crops only when the vegetation is dry. Good crop ventilation will reduce the duration of foliage wetting and therefore prevent infections and lower the impact of the disease.

During harvest and at the end of cultivation, avoid leaving plant debris on the ground or burying them . If you can not do otherwise, the burial will be deep in order to activate their decomposition.
When the very first symptoms are observed, especially if they occur in the nursery, it is strongly recommended to eliminate and destroy the affected plants or plants as soon as possible.

• Next crop

In the nursery

It will be essential to use seeds of irreproachable sanitary quality, even if this bacterium has never been isolated from melon seeds.

The nurseries will be ventilated as much as possible in order to reduce the ambient humidity and prevent the presence of free water on the plants. Those which show symptoms of the disease should be removed from the crops and destroyed.

Tools will be disinfected, and workers will wash their hands before and after handling plants.

Some treatments * from copper could be made proactively to ensure the production of the healthiest plants as possible.

At the field

The rotations of 2 to 3 years with non-host plants including cereals, will be preferable.

They avoid planting too early in the year , so as not to expose plants to low temperatures and wet. The proximity of beet, onion and melon crops, especially if they are already infected, should be avoided.

The fertilization must be balanced in any case insufficient or excessive. Balanced manures will be implemented. Excesses of nitrogen should be avoided because they lead to obtaining exuberant plants, succulent tissues, more sensitive to this bacterium and other pathogens.

Line or localized irrigations are preferred to those by sprinkling.

The application of copper-based products will delay the development and spread of this bacteriosis ( e-phy ). The treatments will be carried out preventively at a rate of 7 days. It will be best to treat the plants when they are dry and just before rains are expected. Remember that once declared, this bacteriosis is difficult to stop.

All the melon varieties currently cultivated are more or less susceptible to this bacteriosis.


* Chemical control : As the number of pesticides available for a given use is constantly changing, we advise you to always confirm your choice by consulting the e-phy site of the Ministry of Agriculture and Fisheries which is an online catalog of plant protection products and their uses, fertilizers and growing media approved in France. This also applies to all biological products based on microorganisms or natural substances.