Florida may close its citrus nurseries for a year.

Officials in Florida say the state’s 300 commercial citrus nurseries should be closed for a year, which would be the toughest step so far in a yearlong battle to save the $2.5-billion industry from citrus canker. The shutdown is the only way of halting the spread of the contagious disease, members of the state-federal Citrus Canker Task Force said in recommending extension of a quarantine imposed earlier this month. Agriculture Commissioner Doyle Conner, who declared the indefinite ban Sept. 6, said he would not accept the task force’s recommendation until the problem had been studied further. Citrus canker kills trees but does not harm humans.