The Environmental Protection Agency has renewed the Florida Section 18 emergency use exemption for streptomycin to manage citrus canker on grapefruit.

The action comes after a request by the Florida Fruit & Vegetable Association in January for a Section 18 for FireWall 50WP from AgroSource Inc., Cranford, N.J.

The EPA originally issued the exemption in September 2012.

Although alternative products are available to fight citrus canker, they can cause phytotoxicity to grapefruit rind during hot periods. The physiological reactions are what created the non-routine emergency situation, according to a news release.

All grapefruit growers in the state are eligible.

The exemption allows for a total of two applications of FireWall 50WP at 11 ounces of formulated product per acre per application by ground. Growers must allow at least 21 days between treatments and a 60-day pre-harvest interval.

The applications can only be made during hot and humid weather when use of other products, such as copper, would cause phytotoxicity.

The exemtion covers applications to 54,000 acres of Florida grapefruit.

As part of the Section 18, the canker organism Xanthomonas axonopodis pv citri must be monitored for field susceptibility to streptomycin to determine whether microbial resistance is developing from its use on grapefruit.

The review process took longer than usual because the EPA also had cross-resistance concerns over use of similar antibiotics in humans that had to be considered.

Midway through the process, the FireWall formulation also was changed.

Questions about FireWall's use on grapefruit should be directed to the FFVA at 321-214-5200