In the most authoritative view yet on the state of the withered U.S. crops, the report -- based on samples from parched, scorched fields -- showed the corn harvest would drop 13 percent from last year, with yields 25 percent below normal.The shooting will likely bring the number of fatal "green-on-blue" incidents - in which Afghan security forces turn on their Western allies - to 24 over the last 12 months, according to ISAF. The military alliance has yet to confirm that the gunman behind Thursday's attack was an actual member of the Afghan forces, and not just a militant who had acquired a uniform to get nearer his targets. ISAF only counts attacks by serving members of the Afghan security forces as green-on-blue incidents.