Late season corn diseases such as stalk rots, ear rots and foliar diseases such as Goss's Wilt may be the next problems impacting this year's corn crop. So, corn farmers will be wise to scout their fields for early signs of these problems. Pioneer research scientist Scott Heuchelin says the warm, humid weather has primed the pump for fungal diseases in the later part of this growing season.
When the crop reaches physical maturity, it stops actively growing and uses its energy reserves to fill the ear. During this time, root and crown infections, established earlier in the year during saturated soil conditions, can take off and aggressively infect the plant's crown and stalk tissues. Heuchelin recommends that if top dieback is evident, test the stalk integrity by pinching the base of the stalk or pushing the plant to the side to assess lodging potential. Fields with significant lodging potential should be harvested first to preserve yield potential.
Bleaching out of the ear leaf or husk leaves could be a sign of ear rots. Agronomists and researchers often see ear rots show up in Indiana, Ohio, Illinois and Ontario. This season, additional regions that experienced significant precipitation and humidity may fall victim, too. Growers may want to harvest early and dry corn to 15% moisture or below to prevent further molding during storage.
Goss's Wilt is historically more localized in the Great Plains, but according to Heuchelin it's recently been reported in eastern Nebraska, the Dakotas, Manitoba, Minnesota, Iowa, Wisconsin, Illinois and Indiana. It typically occurs as the result of hail events and storms. The Goss's wilt bacterium can infect the leaves where they have been abraded. Fungicides will not help. Producers must manage the debris, which is the source of the inoculum, and work in rotation and tillage along with resistant genetics.