If you're looking for a cookbook answer on how to prevent a repeat of ear rots in 2010, you won't find it here. You can fire up the tractor and till until your heart's content, and some will say that you will help reduce your odds of having a severe infection next year from ear rots by taking this measure. However, others point out that doing so still doesn't guarantee that the disease won't blow into your field from somewhere else. If the inoculum is there and the weather is right next growing season, odds for a return performance are more favorable than if weather conditions turn against the disease in '10. And if you can foresee weather conditions that far in advance, even though you might love farming, you could likely make yourself more income in another profession- as a weather prognosticator.
"Fields with a Diplodia or Gibberella problem this year should have a management plan fro the next year to help manage the return of the fungus," notes Barry Soliday of icorn.com. "Crop rotation is one of the best tools to prevent a reoccurrence by reducing buildup of (fungal) spores through decomposition of infested corn residues."
Purdue University disease specialists Charles Woloshuk and Kiersten Wise encourage tillage if you're following a corn rotation, coming back with corn in the same field next year. However, they also suggest rotating out of corn. And don't consider wheat as an option, since that crop can harbor the same organisms.
"Rotation out of corn or wheat will allow infected residue to degrade, reducing the presence of the causal fungus," Woloshuk says.
Soliday notes that tillage practices that partially or completely bury corn residue can provide a substantial increase in disease control. "That's because it's where these pathogens reside," he says.
No-till believers, and those who legitimately need to no-till either to meet their highly-erodible land plan (HEL) with FSA, or because soil erosion is a real threat on sloping land, argue that burying residue doesn't mean you won't get the disease in a field or fields next year. Most experts agree, but some also note that if pathogens have to blow in, infection may not start as early as if the corn is infected by inoculum still in the field from the year before,. The earlier these diseases get a foothold, often the worse the damage and potential yield loss.
"Diplodia and Gibberella can develop to some extent in any corn hybrid if spore levels are high and weather conditions are right fro infection," Holiday says. "However, hybrids do differ in their level of susceptibility. Planting several hybrids with differing maturities will help spread the risk by spreading out your window of silking."
Woloshuk and Wise also suggest discussing how hybrids you're considering shake out on resistance to these diseases. Ask your seed supplier pointed questions about each hybrid that you might buy to plant in 2010.
One simple trait that might be overlooked could play a factor in susceptibility to ear rots. "Varieties with tight husks appear to be more vulnerable to Gibberella ear rot," Soliday observes.