NY apple crop faces fungal threats from global warming
Apples in New York are under attack from new fungal species that cause the fruit to rot.
While the standard species of apple rot has long been a challenge to farmers, researchers from Cornell University this week have identified species in the Hudson Valley previously found in fruits such as bananas and mangos that grow in warmer climates.
Moreover, they have discovered an entirely new species of fungus that may pose even more challenges going forward.
“We were shocked to see that,” Srdjan Acimovic, senior extension associate at Cornell University’s Hudson Valley Research Laboratory said of the new species, and the one that had heretofore been in warmer climates. The discovery is feeding into global concerns about new plant pathogens popping up in more and more places.
New York apple growers have long contended with the standard variety of apple rot.
That would be the fioriniae species of the Colletotrichum genus of fungus.
But starting in 2016 farmers in the Hudson Valley and elsewhere were noticing a different kind of rot.
So Acimovic’s lab, along with researchers from Pennsylvania State University, Louisiana State University and the Canadian Food Inspection Agency started looking into apple crops.
The New York researchers took hundreds of apple samples in 2017 and 2018 from Ulster, Dutchess, Orange, Westchester, Greene, Columbia, Suffolk and Albany counties.
As expected they found the C. fioriniae species, which still accounts for about 60 percent of the fungal samples.
But they also found the warm climate species, C. chrysophilum in 25 percent.
And the entirely new species, C. noveboracense was in about 12 percent.
The species is named for New York in Latin and was described Monday in the journal Scientific Reports. It is similar to the warm weather species.
“It will just abruptly show up in the orchard right about mid-July or earlier,” Acimovic said of the fungal pathogens.
Now that these fungi have been found in New York, researchers will look at potential fungicides to manage them.
They will also begin examining the DNA of the new species in efforts to breed apples that are resistant to the rot.
While C. chrysophilum comes from a historically warmer climate, it’s hard to quantify the extent to which global warming has caused it to show up in New York apple orchards.
But the northward progression of other forms of biomass, such as ticks, is well-known.
And, Acimovic said the concern about new fungal variants is global.
“Papers are really popping up on a monthly basis,” he said of scientific journals including those in Australia and Asia that are starting to document the apple rot.
All told, these fungal species can cause crop losses of up to 25 percent for farmers. For organic growers it can be close to 100 percent, said Acimovic.
At 29.5 million bushels per year, New York is the nation’s second-largest apple producing state behind Washington. That’s worth an estimated net income of $260 million for Empire State farmers, according to federal statistics.
There are 600 commercial growers and about 700 orchards in the state.