US Florida seeks emergency exemption for antibiotics to combat Huanglongbing

The US EPA has received a request from the Florida Department of Agriculture and Consumer Services for specific exemptions to use the pesticides oxytetracycline calcium, oxytetracycline hydrochloride, and streptomycin sulfate to treat up to 388,534 acres of citrus to control Candidatus Liberibacter asiaticus the bacteria which causes Huanglongbing (HLB), also referred to as citrus greening disease. Because the applicant proposes use of pesticides which are also used as human and animal antibiotic drugs, EPA is soliciting public comment before making decisions whether or not to grant the exemptions.

 

As part of the requests, the applicant states that Florida’s citrus production will be seriously jeopardized if HLB cannot be adequately controlled. The disease has been known in China for more than 100 years, and is considered to be the most serious disease of citrus worldwide, affecting all citrus species and their hybrids. Since the discovery of HLB in Florida in 2005, it has rapidly spread to all 34 commercial production areas in the state, and the applicant claims that the severity of HLB far exceeds that of any previously known citrus disease. HLB causes decreases in fruit yield and quality, and infected trees decline and eventually die, even when producers incorporate all management options currently available. Thus far, efforts to control the disease have focused on removal of diseased trees, nutritional support, and rigorous efforts to control the Asian citrus psyllid (the vector of the HLB bacteria). However, research over the past several years on use of agricultural antimicrobial agents has shown promise for suppressing the disease and improving tree health. The applicant is now requesting use of three antimicrobials, oxytetracycline calcium, oxytetracycline hydrochloride, and streptomycin sulfate, and indicates that the recent research suggests that multiple bactericide applications will be necessary to improve tree health and suppress the effects of HLB disease year-long on infected citrus trees. The HLB disease has caused significant economic losses as well as losses of jobs related to citrus production. The applicant states that millions of trees have been lost in both commercial and residential citrus, and the long-term viability of Florida’s citrus production is threatened if the disease cannot be effectively managed. 

 

The proposed application method for all three materials is foliar spray using ground application equipment. The applicant proposes to make up to three applications of streptomycin sulfate at a rate of 0.45 lb. per acre on up to 388,534 acres of citrus, for a maximum use of 520,540 lbs. of streptomycin sulfate. The applicant also proposes up to eight applications of oxytetracycline calcium at a rate of 0.255 lb. per acre on up to 388,534 acres of citrus for a maximum of 762,309 lbs. Additionally, the applicant proposes up to three applications of oxytetracycline hydrochloride at a rate of 0.27 lb. per acre on up to 388,534 acres of citrus, for a maximum use of 314,712 lbs. Applications are proposed statewide in citrus production areas.