Abundant rainfall during June means greater risk of corn leaf diseases, according to Iowa State University Extension plant pathologist Alison Robertson.

"Northern corn leaf blight (NCLB) has been reported from several fields in southern Iowa," she said. "You will remember that this disease was widespread in Iowa in 2014 and severe on susceptible hybrids. Since the fungus survives the winter in corn residue, we likely have above normal inoculum present."

NCLB favors cool weather with frequent precipitation. New lesions may develop every...