"Both fruits are vulnerable to a nasty disease called fire blight that can devastate orchards. So organic labeling standards allow for antibiotics to be used on apple and pear trees. That exemption is set to end in 2014 -- but growers say they need a little more time."
"Apples and especially pears are vulnerable to a nasty bacterial infection called fire blight that, left unchecked, can spread quickly, killing fruit trees and sometimes devastating whole orchards.
'It's basically like a gangrene of your limbs. It's hard to stop' once it takes hold, says Ken Johnson, a plant pathologist at Oregon State University."