By Clint Thompson
Neopestalotiopsis disease has been widespread across strawberry fields in the Southeast. It started in Florida and has continued in South Carolina.
Natalia Peres, professor of plant pathology at the University of Florida/IFAS Gulf Coast Research and Education Center, said the increase in disease infestations is not surprising.
“It’s not surprising considering we’ve had some weather like some rain and some wet weather. It’s not totally surprising,” Peres said. “Any time it’s wet, it helps to spread the spores of the disease. If it stays wet for too long, like prolonged leaf wetness, that’s usually when we have the outbreaks.
“We have had some of those conditions like in late November, around Christmas and then around New Year’s Eve. What we’re seeing now is the effect of that wet weather. It’s highly linked to weather which is unfortunate, because we can’t really control the weather.”
Neopestalotiopsis causes leaf spots on strawberry plants. It develops quickly and produces spores on the leaves. It can cause severe leaf spotting and fruit rot under favorable weather conditions. The disease has been a concern ever since it was first discovered during the 2018-19 season across five farms in Florida. It was attributed to one nursery source in North Carolina.
More than 20 farms experienced the disease during the 2019-20 season, and the disease was attributed to two nursery sources early in the season in North Carolina and Canada. It was also discovered during the 2020-21 seasons in fields that had it the prior season.
This year’s outbreak is much different than last year which instances were minimal. Again, the weather played the determining factor.
“Last year it was out there but never got really bad until at some point in March, like mid-March, it started exploding. But by then the season was almost over (in Florida). The impact was not as much but if you think about last season compared to this season, last season was pretty dry. Last season we didn’t have any of those times where leaf wetness was above 36 hours,” Peres said. “That’s the number we’ve been noticing. When it’s more than 36 hours, that’s when it really explodes. This season we had those conditions around Christmas or just before Christmas, I think (Dec.) 21 and 22 and then again around New Year’s Eve to Jan. 2, something like that.”