Winter storms and flooding create "water mold" in some California crops
LODI — This winter's series of atmospheric rivers created pathogens that are attacking crops across California.
"Because of climate change, there is more moisture in the atmosphere," said Professor Emeritus Dr. Michael Hoffman from Cornell Institute for Climate Smart Solutions.
Crops like some almond trees are now covered in gumming and are being attacked by the pathogen "phytophthora."
"They are known as water molds," said UC Davis Ph.D. candidate for plant pathology Alejandro Hernandez Rosas.
Scientists told CBS13 phytophthora is usually a soil-borne disease that attacks the roots of trees, but now the water mold is attacking the leaves, branches and fruit itself.
"It was able to swim sort of up the trees and cause diseases in different parts of the trees that you would never see otherwise," said Dr. Hoffman.
The phytophthora produces swimming spores, and with the wind, droplets of water contain the swimming spores and can infect the upper canopy of the tree and then start infecting the branches.
James Chinchiolo's cherry trees in Lodi are thriving, but he said he is paying attention to leaf size, leaf color and fruit size. Overall, he has seen a positive impact from the atmospheric rivers.
"It has allowed for water to penetrate down into lower profiles," said Chinchiolo. "In other words, five feet and below."
The direct risk of pathogens like phytophthora to humans is minimal.
"This disease does not necessarily infect the fruit, so you would not have to worry about eating the fruit covered with phytophthora," said Hernandez Rosas.
The tree is instead at-risk, and it may cause it to produce a smaller, less desirable crop. The more trees that are infected, the fewer the crops that will be available which equals higher prices at grocery stores.
"If you have severe losses in the orchards, then you are going to have that much less produce that you are going to give back to the consumers," said Hernandez Rosas.
Farmers are working on better drainage to avoid the future spread of this water mold.
"If the orchard becomes flooded, then that pathogen can essentially swim from one tree to the next," said Chinchiolo.
UC Davis researchers told CBS13 they have gotten around 20 calls from farms impacted by the pathogen so far this year. The last time experts saw this pathogen so potent was in the late 1990s during El Nino.
"This disease kind of went unnoticed for all these years," said Hernandez Rosas.
Some of the most susceptible crops are almonds, cherries, olives, pistachios, strawberries, tomatoes, potatoes, blueberries, cranberries, pears, cherries and apples.
