Working closely with potato growers around the world, I’ve seen firsthand how much yield and quality can be lost to diseases that go unnoticed or unmanaged.
One of the most underestimated culprits is black dot. Caused by Colletotrichum coccodes, this pathogen thrives in stressed plants and plays a key role in the early die complex. But despite its impact, it’s often confused with or overshadowed by more familiar threats like verticillium wilt.
One thing has become clear to me: by not managing black dot, we’re leaving significant potential on the table.
Argentina: A Wake-Up Call for Yield Loss
When growers in Argentina adopted potato production practices from the Pacific Northwest and Western Canada, they expected success. In fact, yields on virgin land dropped by about 60% after just three seasons.
Initially, verticillium was blamed. Traditional methods to suppress verticillium were unable to solve the yield problem. When our sister company introduced trials in Argentina with a soil fumigant driven by the active ingredient chloropicrin, the turnaround was striking: yields rebounded to near virgin land production in just one season. The culprit wasn’t verticillium after all — it was black dot. Seeing those results made me realize how much we’ve underestimated black dot and how crucial it is to use the right tools to tackle it.
Australia: Quality at Risk
In Australia, where the fresh potato market is all about quality, black dot is a not-so-hidden issue. On some fields only 40 per cent of potatoes make the highest-grade supermarket standard, and black dot is a big reason why. Despite strict quality control methods, I’ve walked through stores in Australia and seen beautiful potatoes with blemishes that could easily have been prevented. Those less than perfect spuds represent only a fraction of those that were culled — at significant cost to the producer — long before reaching the supermarket, contributing to food waste.
Chloropicrin hasn’t yet been widely adopted there, but the potential is enormous. If growers could reduce their rejection rate by even 10 per cent, it would revolutionize their profitability. It’s clear that sticking with traditional disease suppression programs is holding them back from meeting their quality goals.
Canada: Growing Awareness
Here in Canada, the conversation around black dot is finally picking up. For years, diseases like verticillium wilt took center stage, but now we’re realizing just how much black dot contributes to yield loss. I’m now regularly part of discussions with researchers and growers alike who are starting to see how Strike, a soil fumigant that uses the active ingredient chloropicrin, can fit into an integrated approach to suppress black dot and boost plant health.
The Global Takeaway
The reality is that outdated, conventional products aren’t equipped to handle today’s challenges, including black dot. Relying on these products rather than looking for new solutions costs more than many realize. Chloropicrin has shown time and again that it can deliver real results, whether it’s restoring yields in Argentina, helping Australian growers improve quality, or giving Canadian farmers a better way to fight back against the early die complex.
As an industry, we need to ask ourselves: what are we leaving on the table? By rethinking our soil fumigation strategies, we can unlock better yields, healthier crops and stronger profits. The solutions are here — it’s time to make the most of them.
