Embrapa's action reduces ripe grape rot infestation by 95%

A joint effort between Embrapa, state agencies, and city governments in São Paulo has managed to recover 95% of Niagara grape cultivation on rural properties that are part of the Fruit Circuit, the state's main grape production hub. In 2024, the region's wine industry was hit by an epidemic of the disease known as ripe grape rot, caused by the fungus Glomerella cingulata, which decimated entire crops in Jundiaí, Louveira, Itatiba, Itupeva, Jarinu, Indaiatuba, and Elias Fausto. Losses reached 100% on some farms, leaving producers discouraged and uncertain about the future of their activities. 

The initiative, called the Emergency Plan to Control Grape Ripe Rot, selected 13 rural properties in the region for fungicide applications, among other best practices recommended by Embrapa's technical teams. Those that fully followed the guidelines achieved yield recovery rates of up to 100%. On the other properties, the disease also reduced, albeit to a lesser extent, with improvement rates reaching 95%.

The measures proposed by experts from Embrapa Uva e Vinho (RS) and Embrapa Territorial (SP) are the result of tests and collections of cultural remains carried out in these spaces, with the aim of diagnosing and stopping the spread of the disease, based on the identification of species in the asexual phase of the Glomerella and assess their sensitivity and tolerance to fungicides. Learn more about these actions here.

The disease, which primarily affects pink and white Niagara grapes, causes ripe berries to rot and drop, making the harvest commercially unviable. In previous harvests, some producers, to avoid greater losses, even harvested early, selling unripe grapes, compromising quality and market value.

The impacts on the region's wineries threatened to even disrupt traditional events, such as the annual Grape Festival in Jundiaí. "The disease still persists in some vineyards, but with a much lower incidence. It remains a concern, so we remain vigilant. Even so, we believe there will be no negative impact on tourism," says Sérgio Mesquita Pompermaier, director of the Agribusiness Department of the Jundiaí City Hall. 

Costly failures

During the final months of 2024, Embrapa scientists visited farms and spoke with producers about management practices. Priority recommendations included removing infected crop residue, applying fungicides while plants were still dormant, using effective products at critical stages (such as flowering and early ripening), and paying special attention to application technology—a critical point identified by the researchers.

Lucas Garrido, a researcher at Embrapa Grape and Wine, explains that a combination of factors contributed to the emergence of the epidemic in 2024, such as above-average temperatures, constant humidity, and the presence of contaminated crop residues. The Embrapa team also believes that a significant portion of the losses were due to management errors, such as the use of ineffective fungicides, incorrect application rates, or unregulated equipment. "In some cases, the correct product was on the property but was not used. Or it was applied incorrectly. This needs to change," says Rafael Mingoti, an analyst at Embrapa Territorial and one of the initiative's coordinators.

Faced with a scenario of losses and combating a microscopic enemy, it's necessary to change our behavior toward the disease. "Producers who opened themselves up to knowledge, tested, and correctly applied products and care are now reaping the rewards. Literally," emphasizes Mingoti.

This is the case of Atalívio Rufino, who owns a farm in the rural area of ​​Elias Fausto. Last year, he lost almost all of his production, and financial difficulties led him to lay off employees. His property was one of those selected for Embrapa's experiments. Since then, he reports many changes. "Before, we removed the branches and bunches that rotted, but not as diligently. Sometimes, we even left them or chopped them up with a brush cutter. Now, we're removing, burning, or discarding them far away. We also made changes to the spraying process. We've adjusted the equipment and increased the volume of tail," he says. 

Scientific advances will support disease management protocol

The research will also contribute to understanding the disease. Studies are being conducted by the Biological Institute to identify the species of the fungus in the genus Colletotrichum (asexual form of Glomerella), collected in different areas of the Fruit Circuit. Diversity can be found throughout the region, which implies variability in response to treatments. The results of these studies will enable improvements in chemical and biological control.

"It's not yet possible to say whether there is resistance to any fungicide, but the possible presence of multiple species reinforces the importance of understanding the causes of the problem before tackling it," explains Mingoti.

These data will be used to support broader research projects, including a proposal submitted to the São Paulo Research Foundation (Fapesp), which envisages the development of a warning system and a consolidated protocol for integrated disease management.

Check out integrated control management practices

Embrapa scientists emphasize that the protocol may vary between cities, and sometimes even between properties. However, some common practices can be adopted to achieve better control results. Here are some of them:

●Elimination of infected crop residues after harvest;

●Applications in winter, still during dormancy, to reduce the pathogen;

●Use of effective fungicides, applied at strategic stages (flowering, pea-grain, pre-cluster closure, beginning of ripening);

●Alternation of systemic and contact products;

●Reapplication of biological products after rain;

●Use of biological products and essential oils, especially in the final stage of maturation, to reduce the risk of waste;

●Adjustment and regulation of sprayers.

Confidence in the future

In addition to the technical gains, the collaborative action had a positive impact on the spirits of winegrowers. In 2024, the prevailing sentiment was frustration and pessimism. Today, according to Mingoti, that perception has changed. "There's more security. Producers understand that there is a solution—not a magical one, but a technical one. And those who followed the recommendations harvested more and better," he states.

After successfully reversing the situation, producer Atalívio Rufino believes his example can be followed by other colleagues who are thinking about giving up. "I'd say it's time to persevere. I've seen that it's possible to beat the disease. It's not easy, but the rewards come. Just look at our example here on the farm: today we're harvesting," he celebrates.

Field Day will present results and recommendations

The results achieved, application strategies, and clarification of producers' questions will be addressed at the seminar and Field Day, scheduled for September 16th and 18th, respectively. The seminar will take place at the headquarters of the Jundiaí Agricultural Association, from 13:30 pm to 18:30 pm, while the Field Day will take place at Sítio Dois Irmãos, in Elias Fausto, from 14 pm to 17 pm. Interested parties can register for the seminar here and for the Field Day here.

In addition to field data, there will be panels on application technologies, management under plastic cover (which alters the microclimate and diseases) and the impact of cultural practices on disease control. Glomerella. 

Despite partial control of the disease, the team states that now is not the time to relax. The lack of an official protocol requires extra attention from winegrowers. The spore can remain dormant, even outside the field, and preventative management—starting in winter—remains the main defense. "This is not the time to let our guard down," Mingoti emphasizes. "It is essential to remain vigilant, apply pesticides correctly, adjust our strategy based on weather conditions, eliminate crop residue, and regulate equipment. Only then will we consolidate the progress made so far," he warns.