Basil crops attacked by fungus
Known as basil downy mildew, the fungus causes lesions and spots on the plant but doesn't kill it. It does, however, reduce the quality of the plant.
"That's pretty much a loss for the grower," said Steve Koike, plant pathology farm adviser with the University of California Cooperative Extension.
Koike told Consumer Ally that he's heard from some growers who say the fungus has damaged about one-fourth to one-third of their crops. Other growers, however, have reported a loss of less than 10%. He said organic growers are likely the hardest hit because they're unable to use a fungicide on their plants.
Richard Raid, professor of plant pathology at the University of Florida Everglades Research and Education Center in Belle Glade, described the outbreak as serious because basil is the most commonly grown herb. He estimated the loss in the U.S. to be in the millions of dollars. A field of basil, for example, can be worth more than $10,000 an acre, he said.
"For the potted basil grower, basil is a major portion of their market and those guys have been hit really hard," he said.
The fungus, first reported in the U.S. in 2007, has affected Genovese and sweet basil, the kind most commonly used in pesto and other dishes. Lemon and blue basil are less susceptible to the disease. It is sensitive to warm temperatures and drying conditions such as wind and sunlight.
If growers can manipulate the growing conditions, they might be able to reduce the fungus' impact. Koike also said the problem is cyclical. Last year, for example, the fungus was around for about a month or so.
"But then it got sunnier and drier, so the mildew subsided," he said.
The fungus can take several days to show up, so shipments of the plant may leave okay but arrive to their destination in bad shape, Raid said.
"It's capable of spreading pretty long distances and over short periods of time given favorable weather conditions," Raid said.
Koike's said he's not aware of stores reporting a shortage of basil, so for now, consumers shouldn't have a problem buying it.