New Fungus Is Linked to Peru’s Grape Vine Collapses

A new fungal lineage has been linked to a collar rot disease that has been damaging young grapevines in Peru since 2022, according to a preprint posted this week on Preprints.org.

The study says the pathogen belongs to the genus Pleiocarpon and appears to represent a previously unreported lineage. Researchers found the fungus after growers reported vine collapses and lesions at the base of trunks in newly planted vineyards. The problem has raised concern because it affects young plants before they can establish strong root systems and begin producing fruit.

In greenhouse tests, the scientists reproduced the disease by inoculating grapevines under controlled conditions. They reported that symptoms developed most readily when temperatures were between 25.7C and 31.5C, suggesting that warm conditions may favor infection and disease development. That finding could help growers and plant health officials narrow down periods of higher risk and adjust sanitation and monitoring practices.

The report adds to growing evidence that trunk and collar diseases remain a serious threat to vineyards in warm production regions. Peru’s grape industry has expanded in recent years, especially in coastal areas where temperatures can support rapid vine growth but may also create favorable conditions for fungal pathogens.

Because the work is still a preprint and has not yet been peer reviewed, its conclusions should be treated as preliminary. Even so, the identification of a new Pleiocarpon lineage gives researchers a clearer target for follow-up studies on diagnosis, spread and control.

The authors say further work will be needed to determine how widespread the fungus is in Peru, whether it is present in other grape-growing countries and which management measures can limit losses in affected vineyards.