The rugose virus (ToBRFV) is a threat to tomato and pepper growers worldwide. In Argentina, it was detected for the first time in February 2023 in the province of Corrientes and later in the horticultural belt of the city of La Plata and Mar del Plata (Buenos Aires), as well as in Salta tomato crops. Because it does not have an insect vector, the viral particle is stable, and its transmission is mechanical. Human activity turns out to be the main way the virus spreads in crops (through seeds, seedlings, and crop management). For this reason, a team of specialists from the Argentina National Institute of Agricultural Technology (INTA), the National Agri-Food Health and Quality Service (Senasa), and the National Seed Institute (INASE) has shared recommendations to prevent, control, and reduce its dispersion.
Paola López Lambertini, specialist at the Institute of Plant Pathology of INTA, pointed out that "the tomato rugose virus, when it infects young plants, can cause yield losses ranging from 30 to 70%". And she added: "The incidence of the disease can reach 94-100% when management is not adequate."
In this sense, it is important to focus on management practices that allow slowing the progression of the disease. "It is essential to combat the virus, so it is necessary to implement phytosanitary strategies for prevention and control," said López Lambertini and clarified that to achieve good results, it is very important to work together among all the links in the production chain - seedbeds, planters, and producers- of both crops.
On the other hand, for planters and producers, the INTA specialist indicated: "Limit the number of people who enter the crop, place rugs or trays to disinfect shoes at all entrances, use exclusive clothing to work in each greenhouse (the which is left in it and washed) and disinfect workers' hands frequently."
Disinfect equipment, tools, footwear, and other non-porous surfaces, one option is to use 10% bleach. A good alternative is to have, for example, two blades to leave one disinfecting while the other is used. If you have a greenhouse or lot with plants that are infected or suspected of being infected, go to work at the end of the workday. Do not touch the plants when walking between the rows, visually inspect leaves, stem, petioles, calyxes, and fruits to detect plants with typical symptoms of the virus or that are out of type, and then eliminate it and burn it along with the 5 plants that are around the suspicious plant.
"This measure is very efficient to prevent the spread of the disease in the early stages of the crop. In addition, it is essential after transplanting to eliminate diseased plants due to seed transmission," López Lambertini highlighted. For this reason, it is important not to move the plant or fruit if symptoms compatible with the virus are suspected.
And he pointed out: "Do not water excessively. If irrigation is carried out by furrow, lock the end of each furrow to avoid water spillage and dispersion of viral particles." In the last links, for distributors, it is recommended to clean the vehicles, while for small producers and family gardens, not to use tomato and pepper fruit seeds from producing regions where the virus is present.
How to detect it
As for the symptoms, Daniel Kirschbaum - horticulture specialist and coordinator of the INTA Vegetables, Flowers, Aromatic and Medicinal Program - detailed: "The symptoms to identify infected tomato plants are leaves with mosaic and mottling, blisters, and narrowing of the leaf blade, necrosis of peduncles, calyxes, petioles and longitudinal necrosis of the stem, uneven ripening in young fruits. While, in pepper, they are leaves with mild mosaic and discoloration of the young leaves, necrosis of the stem and deformation of the fruit." And he added: "Tomato fruit symptoms include discoloration and brown or tan spots. Some green fruits may be infected and remain asymptomatic until they mature."
In this sense, Eduardo Trumper -specialist and coordinator of the INTA Plant Protection Program- highlighted that "it is important to keep in mind that, even if the plant does not present symptoms, it may also be infected." In the case of confirming the symptoms of infected plants, producers are recommended to contact [email protected] or with the INTA or Senasa technicians in the region of the country where you are [email protected]
"The plants are being analyzed to determine the presence of the disease in different regions of the country, which will contribute to the permanent updating of a map of the dispersion of the virus managed by Senasa. This will allow the pertinent phytosanitary measures to be taken for its control," he described.
If the presence of ToBRFV is confirmed, plant residues must be burned, and all materials associated with infected plants, such as threads, etc., must be disinfected. Nothing should be moved from the infected area to other areas within the property. Disinfect the greenhouse at the end of each season. And he added: "Viral particles are very stable, therefore they can remain in the soil, in plant remains, and on stakes for long periods." Prevention is the best defense against the rugosa virus, even when there are plants without symptoms. For this reason, the joint work of each link in the tomato and pepper production chain - seedbed, planter, producers - is essential to combat it.
Source: primeraedicion.com.ar
