Producers whose crops have quality issues need to talk to their insurance company before harvest. Some quality issues are covered; others are not. The following observations and recommendations come from Charles Hurburgh, ISU Extension ag engineer and grain quality expert; Alison Robertson, ISU Extension plant disease specialist; and Connie Hardy, ISU Extension value-added agriculture specialist.
"As we approach harvest, the impact of the drought on grain quality is becoming clearer," Hurburgh told farmers at the Farm Progress Show at Boone in central Iowa last week. "Corn in many areas to the west and east of Iowa reached maturity earlier. Most of Iowa's corn will be past black layer by Labor Day weekend. Soybeans have stopped and started with late rains, but expect pod count and seed size to be pretty well set by Labor Day as well. Regardless of crop and quality issue, please talk to your crop insurance company before harvest. Some quality issues are covered; others are not. Quality issues are resolved in crop insurance by deducting an additional percentage of actual production before calculating the settlement."
* Corn quality considerations this fall. The primary corn quality issues are low test weight/small kernels, significant mold pressure of all kinds in the many acres of downed corn and a general potential for aflatoxin at some level. Stalk strength is poor so expect more downed corn if we get wind or storms in September.
* Test weight and kernel size. The drought- retarded grain fill makes kernels less dense and, therefore, lower in test weight. Low test weight from drought is not the same as low test weight from frost or wet weather (remember the year 2009) in that protein and oil levels will likely be average or even above. This is good news for feeding. Historically, test weights down to 45 pounds per bushel have not had lower energy per unit of weight. The small kernels may partially offset the lighter density of each kernel because more small seeds fit in the test weight volume cup than larger seeds.
As always, low test weight grain will break to a greater degree in handling and will have shorter storage life at a given moisture. A table on the Iowa Grain Quality Initiative's website shows the typical storage time by moisture and temperature. If test weights are 52 pounds per bushel and lower, you need to cut these storage time numbers in half—just like you had to do in 2009, says Hurburgh.
* Do not hold this year's crop at moistures above 17%. Even if it is necessary or advantageous to harvest early, dry immediately, he advises. The 2012 corn should not be put on top of or blended with older corn if you expect to store the corn.
* Downed corn presents another problem. Storms in August put corn on the ground in several areas of Iowa. The downed stalks will be in humid, high mold situations. Studies from the 2009 crop showed that, aside from toxin risks, mold damage can reduce feed energy values by 5% or more. This year the toxin risks are also high. This corn should be taken out of the field and dried as soon as possible.