By Clint Thompson
Citrus producers in the Cold-Hardy Citrus Region must be mindful of citrus rust mites (CRM) amid the warm, humid climate in the region.
Mary Sutton, University of Georgia (UGA) assistant professor and citrus Extension specialist, implores growers in North Florida, South Georgia and South Alabama to be proactive in managing the populations which are currently high.
“They can definitely be proactive and can go out and scout, look for them on the bottom of the leaves, on some of the fruit. Especially with rust mites, they’re very small, but you can usually see them with a hand lens,” Sutton said “Especially if the infestation gets bad enough, it can cause damage to the leaves and the really small fruitlets. As we get closer to harvest, if there are a lot of rust mites, they will cause blemishes to the fruit that will decrease their value as a fresh market fruit.”
According to Jake Price, Lowndes County Extension Coordinator, CRM prefer the lower parts of the tree on the north side, which tends to be the more shaded areas. When CRM feeds on growing fruit, it destroys epidermal cells which fracture, creating a rough surface. When the pest feeds on mature fruit, it creates a brown stain but does not destroy epidermal cells. This results in a polished brown look referred to as “bronzing.”
“They’ll be on leaves, stems, fruit. You tend to see them more on the fruit but that’s closer to harvest when they’re more mature. Right now, we’re just seeing them everywhere,” Sutton said. “There are quite a few different insecticides. They have plenty of options.”