Protection methods

Unlike fungal diseases, there is no curative control method making it possible to effectively control viruses, and in particular PepMV, during culture. Usually, an infected plant will remain infected for the rest of its life.

• During cultivation

The ( pepino mosaic virus Pepino mosaic virus , PepMV), easily transmitted by the plant, but also by the seeds and perhaps the fruits, imposes control of the imports of plants, but also of fruits. This virus, which was not until recently a quarantine virus , is now included in the EPPO alert list, and is the subject of an official surveillance decision at the level of the European community. Thus, several interceptions have been made in Europe on infected material originating from the Netherlands or Spain, including the Canary Islands. Likewise, Canadian inspection services have detected PepMV in tomato fruit from Colorado, Arizona and Texas.

In France , any detection of this virus in a greenhouse must lead to the destruction of the crop and the implementation of compulsory control . The latter imposes in particular:
- report all declared or suspected cases to the Plant Protection Service (SPV);
- disinfect or destroy the contaminated seed lots;
- to apply in particular drastic prophylactic measures in the affected greenhouses.

Currently, countries approach the management of this virus in different ways. Two main situations are observed:
- production areas where eradication measures have not worked, and where the virus is now endemic, producers and their technicians have learned to "live" with this virus, and therefore have a fairly good command of the production of infected plants ;
- countries not yet affected by PepMV, where initially everything will be done to eradicate this virus from the first affected farms in order to prevent it from settling definitively in the production area, or even the country. Note that it will be extremely difficult to locally eradicate the virus. If we want to do this, it will be better to destroy the culture entirely. Otherwise, in many cases, we will try to contain it in a given area of ​​the greenhouse or farm, but with a high risk of failure given the ease of transmission of the virus.

Whatever the situation, growers are often forced to apply more than one of the measures described below to avoid introducing and spreading the virus, or in an attempt to eliminate it from the crop.

If attacks take place in the nursery and are detected early, there is a good chance that a significant proportion of plants will be infected. In this type of situation, you should not take the risk of spreading the virus. Localized eradication is always very uncertain with this type of virus, it will be desirable to eliminate the plants and destroy them by fire. All plant debris present on and in the soil or substrate will be removed and burned and all shelter surfaces cleaned and disinfected. Note that in production areas where the virus is now endemic, such as the Netherlands or Spain, once infections have taken place at a relatively early stage, growers promote the spread of PepMV to all plants. in order to carry out a "pseudo-vaccination". For this, the producers use the lower leaves taken from diseased plants as inoculum. Thereafter, all they have to do is ensure optimal management of these virus-infected plants.

As soon as you have detected the first diseased plants in a crop, and have confirmed the identification of the virus by a specialized laboratory, we suggest that you:
- enter the ranks with a disposable coveralls, gloves, boots and being careful not to touch the plants;
- eliminate the plants developing symptoms by putting them in a plastic bag so that they do not touch other plants when they leave the culture. Several apparently healthy plants must also be removed from either side of the diseased plant (s);
- quickly burn them or bury them deeply;
- tag and quarantine the affected area (s) tagged, work on them last, taking care to use dedicated equipment.

Functional footbaths are installed at the entrances to each greenhouse and cell, which serve either as nurseries or for production. These will be sufficiently filled with disinfectant solution, and kept functional throughout the duration of the culture. Several of the virucidal products * can be used to disinfect tools, walkways, greenhouse structures ( e-phy ).

Subsequently, you should not enter or leave the greenhouses or compartments without washing your hands with at least hot soapy water, or even with a disinfectant. Wearing disposable gloves is often preferable, and they can be more easily disinfected. A virucide can also be used. Note that workers will decontaminate their hands quite often by immersing them in a disinfectant. Several products are reported as effective: skimmed milk (milk proteins reducing the infectivity of viral particles), a solution of a phosphate buffer or a detergent. They will do this before, and repeatedly during and after their activities in the nursery or greenhouses.

The greenhouses will be locked and they will be prevented from accessing them by any person not involved in the operation. Any visitors should wear special clothing, overshoes and latex gloves. Pets will be prohibited in the greenhouse. Likewise, avoid passing bumblebee hives from one greenhouse to another.

As far as workers are concerned , it is important to dissuade them from bringing and consuming tomatoes from outside the farm for their meals, as these can introduce the virus. The renewal and cleaning of their clothes will be managed as well as possible.

The equipment or tools will under no circumstances be loaned to producers of other market gardening operations. The tools will be disinfected with a virucide. It is sometimes recommended to soak them for 20 minutes either in a 10% trisodium phosphate solution or in 3 ° chlorinated bleach.

All pruning and stripping debris should be removed and destroyed as it goes. They will not hang out in the aisles under any circumstances. These, as well as the cemented corridors, must be disinfected with an approved virucide. The burning of crop residues or their burial with quicklime (volume to volume) will be systematically organized. Under no circumstances will they be placed outside the greenhouses and left in a pile.

The water and nutrient solution will be filtered and disinfected. Pasteurization, ozone and UV rays would be effective preventive measures in this regard.

At the end of cultivation , all the plants (especially the root systems, in which the virus keeps longer), the substrates, the material, the tools, etc., will be taken out of the shelters, taking care not to shred the material plant, which would risk leaving infectious plant fragments. Once the shelters are empty, the surfaces will be cleaned with pressurized water. The irrigation circuit should be disinfected with nitric acid at pH 1 to 2, for 24 hours, then rinsed with clean water. The drippers should be stripped of all organic matter and disinfected. Subsequently, the entire greenhouse will be treated with a disinfectant * ( e-phy ). This will be used at a sufficient concentration and left to act for several minutes in order to effectively eliminate the virus.

• Next crop

Of course, many of the measures detailed above will have to be implemented during the next culture. After eliminating PepMV from the farm, it will above all be necessary to limit as much as possible the risks of its introduction and its extension into it. This will require the use of healthy plants which will be set up in a farm free from any source of contamination.

In the event that the cannot be moved nursery which was contaminated the previous year , disinfection of the soil (with fumigant, steam ) and the equipment used is essential.

As the virus can be preserved in the soil for several years, soil- crop rotations long will be considered in the open field, in the same way as for borne diseases. We should be particularly wary of old contaminated plots, in which root residues persist.

The seeds used for sowing must be sound. In case of doubt, they will be disinfected in the same way as for ToMV. Several products are recommended to eliminate PepMV from the seeds without too much penalizing the germination of the seeds subsequently, alone or in combination: sodium hypochlorite, trisodium phosphate, Menno-Florades After these different treatments, the seeds should be rinsed under running water, shaking them well, then dried quickly. We advise you to discuss this with your technician in order to use the procedure in force in your country. Heat therapy treatments are also reported, as PepMV is very sensitive to high temperatures.

The health of the plants in the nursery and before planting will be carefully checked several times. It will be preferable that the personnel working in the nursery, do not intervene in the cultures in order to avoid the risks of introduction of the virus.

We should be wary of plants and seeds from countries already affected by PepMV: guarantees must be given to you on their sanitary quality. Producers should be wary of varietal trials carried out on their farms. Indeed, some of them seem to have been infected through new varieties tested for seed companies.

In countries where the virus could not be eradicated, in particular in the Netherlands, grafting on rootstocks vigorous (Maxifort, Beaufort, Eldorado) makes it possible to compensate for the effects of the virus and to obtain more vigorous plants , and therefore expressing less viral symptoms.

If despite the measures taken, some attacks occur after planting, refer to the measures to be taken during cultivation.


* 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.