Addendum on corn stalk strength and disease

After my post yesterday about stalk strength, a seed company representative sent me images of substantial lower-canopy damage of southern rust in certain fields in western Kentucky (see figure).  I hadn't seen this level of damage in my own field visits this season, but this level of damage is certainly capable of affecting stalk health.  As explained yesterday, if leaf blighting occurs during grain fill, the corn plant often "cannabilizes" the stalk to fill the grain.  This can result in weaker stalks.  

Southern rust of corn causing foliar dessication. Note the dessication of leaves in the background.  This is a high level of leaf damage and will likely affect stalk strength in this part of the field. (Image from Bill Meacham)

The current forecast suggests that warm nights with dew will continue for a least a few days, so southern rust will likely continue to develop in some fields.  Again, this is another reason to watch fields for weakening stalks, and to consider this in scheduling fields for harvest.