Fruter president Paulo Rocha warns that the cooperative may receive no chestnuts this year, following a 90% production decline since 2020. The future of the island’s distinctive Viana chestnut variety is increasingly uncertain.
There are losses in agriculture that cannot be measured by the weight of a harvest alone. When an orchard falls silent, when trees that have nourished generations no longer bear fruit, something more than an economic activity begins to disappear. A landscape loses part of its memory, a community loses one of its traditions, and the patient relationship between people and the land becomes more fragile. On Terceira Island, where chestnut trees have long occupied hillsides and agricultural plots unsuitable for other crops, that possibility is becoming painfully real. An increasingly destructive combination of disease, invasive insects, and aging orchards has brought chestnut production to the brink of collapse, raising concerns not only about the harvest but also about the survival of a distinctive part of the island’s agricultural heritage.
Paulo Rocha, president of Fruter, the agricultural cooperative on Terceira, has issued a particularly troubling assessment of this year’s chestnut harvest.
“I suspect that this year not a single chestnut will enter the cooperative,” he told Diário Insular.
According to Rocha, producers in Terra Chã and Biscoitos are reporting harvests so small that the available chestnuts may barely satisfy household consumption, leaving virtually nothing for commercial distribution.
The situation represents the culmination of several years of declining production. Between 2020 and 2025, Terceira’s chestnut harvest reportedly fell by approximately 90%, with the chestnut gall wasp emerging as one of the principal causes.
Rocha explained that chestnut trees had already been affected by the fungal disease associated with Gnomoniopsis before the arrival of the invasive gall wasp further complicated their condition.
The insect attacks developing buds and shoots, interfering with the growth of branches and the formation of flowers essential to chestnut production.
Producers have observed drying at the ends of branches, particularly in older trees, where the effects of disease and infestation can be more severe.
The consequences have been devastating for orchards that once provided a reliable supplementary income to local farmers.
Chestnut cultivation was particularly valuable because the trees could thrive in areas where other agricultural production was difficult. Harvests were once sufficiently substantial for Fruter to receive several tons of chestnuts, including quantities shipped from Terceira to São Miguel.
A good year, Rocha recalled, could bring more than three or four tons into the cooperative alone, in addition to chestnuts sold directly by producers.
The crop also had a cultural dimension. In Terra Chã, chestnut production was once sufficiently established to inspire a local chestnut festival, celebrating a harvest that connected agricultural work with community life.
Today, the prospect of little or no commercial production marks a dramatic reversal.
The gall wasp was first detected on Terceira around 2020 or 2021, when a Fruter technician identified the insect on imported chestnut trees at an agricultural property in Praia da Vitória.
Regional agricultural authorities were alerted and subsequently conducted an island-wide assessment.
One proposed response involved introducing a parasitoid insect capable of attacking the gall wasp. The approach had previously been used in mainland Portugal and Madeira, but its introduction in the Azores required technical evaluations and consideration of the archipelago’s particular environmental conditions.
Following several years of assessment, the parasitoid was introduced on Terceira in June 2026.
Rocha welcomed the intervention but cautioned that biological control is a gradual process requiring repeated releases, monitoring, and careful identification of the most affected areas.
He emphasized that the releases must be distributed strategically rather than concentrated repeatedly in the same locations.
The University of the Azores is also involved in the project, alongside regional agricultural authorities.
For Rocha, however, controlling the pest is only one part of the solution. The island must also confront the advanced age of many of its chestnut orchards and the shortage of people trained to propagate traditional varieties.
“Young trees are always more resistant to disease,” he observed, emphasizing the importance of orchard renewal.
Of particular concern is the future of the Viana chestnut, a variety characteristic of Terceira whose continued cultivation depends on preserving local plant material and the specialized knowledge required for grafting.
Rocha recalled José Fernando, a local nurseryman who once performed this work but has since died. He expressed concern that few younger people are entering the profession, creating an additional obstacle to the renewal of orchards.
The disappearance of such expertise would represent another form of agricultural loss: not simply the decline of a crop, but the erosion of knowledge passed from one generation to the next.
Although chestnut production can still be economically attractive because of favorable prices and relatively modest labor requirements, Rocha believes producers need stronger incentives to replant and maintain their orchards.
He hopes that the regional fruit-growing development plan will provide support for new planting, orchard renewal, and the training of nurserymen capable of preserving local varieties.
He also suggested that the protection of the Viana chestnut should receive attention comparable to the measures already established to safeguard indigenous livestock breeds.
Rocha does not believe that the variety will disappear entirely. Some growers and enthusiasts continue to graft and plant chestnut trees, helping preserve the genetic and cultural legacy of the crop.
Nevertheless, he expects recovery to take several years, particularly because the biological control program must continue and many existing trees are already severely weakened.
The uncertainty surrounding Terceira’s chestnut harvest illustrates a broader challenge facing island agriculture: the vulnerability of traditional crops to invasive pests, changing environmental pressures, aging agricultural infrastructure, and the gradual disappearance of specialized knowledge.
For generations, the chestnut tree has been more than a productive species. It has been part of the agricultural landscape, a source of seasonal income, and a quiet expression of the relationship between Terceira’s people and their land.
Its decline is therefore more than a disappointing harvest.
It is a warning about what can happen when biological threats and the passage of time converge upon a traditional agricultural activity.
The future of the Viana chestnut will depend on whether scientific intervention, public support, and the dedication of local growers can restore the orchards before their productive and cultural foundations weaken further.
For now, the approaching harvest offers little encouragement. Trees that once produced enough chestnuts to supply other islands may barely provide for the families who tend them.
And in the silence of those aging orchards lies a question that extends beyond this year’s production: whether Terceira can preserve not only its chestnut trees, but also the agricultural knowledge, local identity, and living traditions that have grown alongside them.
Based on an interview with Paulo Rocha, president of Fruter, published by Diário Insular on October 27, 2026. The photos are also from DI.