Explore the recommendations from UF/IFAS experts for managing citrus black spot in Florida citrus groves.

Citrus black spot is a fungal disease that creates dead black spots on the citrus peel, making it unsellable. The fungus can spread via wind, rain, leaves, tools, and humans. It also causes early fruit drop, which reduces citrus harvest yields. Megan Dewdney, a plant pathologist with UF/IFAS shared black spot management strategies in a Citrus Industry article. See the details of her recommendations below.

Detecting Citrus Black Spot

In the article, Dewdney maintained that “The most important time to scout for black spot is when the fruit begin to change color.” For Valencias, the most common variety affected by black spot, that’s most often in late February to early March that black spot symptoms can be seen, though they can start changing color as soon as December. Growers should look for fungal structures like hard spot and cracked spot, and false melanose and virulent spot.

Knowing the extent that black spot is in your grove “would give you an indication of how much disease you have in your grove and what you need to be planning for in the next season,” Dewdney said.

Treating Black Spot

Dewdney advised using multiple approaches for treating black spot. “You need to be on a monthly fungicide application program from early May to probably late September,” she explained, and added that both reducing the fungus in the leaf litter and pruning dead branches from trees will help in halting the spread of black spot.

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions or concerns about your farm or pasture, contact us and one of our team will be in touch.