Management Advice for Aquatic Weeds

Tacy Calliesweeds

Photo by Mark Mauldin

Nearly every Florida citrus grower will sooner or later experience aquatic weed control problems.

Aquatic plants are necessary for maintaining the balance of nature and offering food, protection, oxygen and shelter to aquatic species. However, maintaining a balance in the aquatic system while sustaining crop success and avoiding loss of income can be a challenge.

Excessive aquatic weed growth can lower drainage rates following heavy rains, resulting in severe root pruning, increased disease rates and leaf and fruit drop. Therefore, growers must manage these weeds.

Brent Sellers is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) agronomy professor and center director at the Range Cattle Research and Education Center in Ona. He shared both chemical and non-chemical management tactics for aquatic and semi-aquatic weeds with citrus growers during a recent webinar hosted by the UF/IFAS Citrus Research and Education Center.

Using chemical controls to manage aquatic weeds may be the most popular and effective method used by citrus growers. According to Sellers, it is imperative to determine the weed species you are looking to control and then choose the appropriate herbicide based on the species. But most importantly, the applicator should always read the label before using any product.

As of 2018, there are 17 herbicide active ingredients approved for use in Florida. Carfentrazone, copper and flumioxazin are a few of the recommended herbicides that Sellers mentioned. Learn more about herbicides registered for Florida use.

For growers looking to avoid using chemical controls, there are several non-chemical management tactics that can be implemented. Draining water from ditches and allowing them to dry out can be an effective method for controlling aquatic weeds, says Sellers. However, there are some species that can withstand periods without water. In order to obtain good aquatic weed control, usually drawdown needs to be accompanied by the application of a herbicide.

Application of catch-screens in ditches, excavating and biological controls also have proven to be effective control strategies.

To learn more about plant management in Florida waters, click here.

This article was written by Ashley Robinson, AgNet Media communications intern in Gainesville, Florida.