Weed management is a key component of Florida’s citrus production. A warm, humid climate and frequent rainfall provide a favorable environment for weed emergence and growth in citrus groves.
Steve Futch, a former multi-county citrus Extension agent for the University of Florida Institute of Food and Agricultural Sciences, delivered a presentation during the 2021 virtual Southeast Regional Fruit and Vegetable Conference. He discussed the best chemical weed-control strategies for Florida citrus growers.
Chemical weed-control programs vary from location to location within the state and can even vary within a given site based on specific conditions such as soil type, variety, method of herbicide application, and the presence of specific weed species.
Herbicides used in a grove are generally divided into two groups: 1) soil-applied preemergence herbicides that should be applied to fairly clean soil surfaces prior to weed emergence and 2) foliar-applied postemergence herbicides that are applied after germination of weed seed.
According to Futch, preemergence herbicides are generally applied two to three times per year. For preemergence materials, application should be properly timed so that the maximum amount of herbicide is in the upper soil profile (0 to 2 inches) slightly before peak weed emergence.
Major preemergence herbicides used in Florida citrus include bromacil, flumioxazin, diuron, indaziflam, norflurazon, pendimethalin and simazine.
As for major postemergence herbicides, glyphosate is particularly popular, says Futch. However, due to its frequent and widespread use, glyphosate is a notable concern in Florida citrus. Weed resistance to glyphosate is a documented issue in numerous crop systems and should be expected. Futch recommends rotating between herbicide classes to minimize the potential for development of herbicide resistance.
For a complete listing of herbicide recommendations including rates, click here.
Furthermore, when using herbicides around young trees, care should be taken to avoid herbicide spray contact with tree bark, stems or foliage as injury may occur. Futch recommends protecting young tree trunks from spray contact by using a nonporous plastic-like wrap.
This article was written by Ashley Robinson, AgNet Media communications intern in Gainesville, Florida.