Citrus canker has long been a presence and concern for Florida’s citrus growers. Growers in North Florida, South Georgia and South Alabama should be wary of its potential spread into the cold-hardy citrus region.
Clive Bock, a research plant pathologist with the U.S. Department of Agriculture, spoke about the disease during the recent Cold-Hardy Citrus Meeting at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) North Florida Research and Education Center in Quincy.
“In this region of Florida and in South Georgia where cold-hardy citrus is grown, recently there have been reports of citrus canker outbreaks,” Bock said. “It has now appeared in Alabama, Louisiana, South Carolina and Georgia. It’s on the move and likely will continue to move. The recent outbreaks in cold-hardy citrus reflect this. The increase in acreage that we have in cold-hardy citrus likely will allow the pathogen to spread more in the coming years as well.”
Citrus canker was observed for the first time in Georgia in 2022. This prompted caution among producers about where they purchased their trees. Hundreds of trees were removed from a single grove that was infected with canker.
The best way to prevent canker is for growers to ensure they purchase trees from a certified nursery. It was observed that navels and grapefruit were primarily impacted, though the disease was found in some satsuma trees.
Unlike citrus greening, which requires a vector to infect trees, citrus canker only needs water or air to spread. Symptoms can appear on the fruit, leaves and twigs. Small blister-like lesions with water-soaked margins and yellow halos can appear on both sides of a leaf.
“It blemishes the fruit, so if you’re selling fresh fruit and they’re blemished, they’re not going to be easy to sell to a consumer from a grocery store shelf. They’re going to be rejected, unfortunately,” Bock said. “For those reasons, everyone is very keen to keeping canker out.”
By Clint Thompson