Corn cob dry

Cob harvest moisture variation

Two main corn cob streams are commercially found today differing in origins and

management. One comes from the collection of corn ears for the production of hybrid seeds,

where parental lines are crossed for the production of corn hybrid seed. The second, and

increasingly important, is the collection of cobs from commercial corn production. The two types

of cobs differ mainly in that for seed production, the ears are harvested at high moisture but are

taken to the facility for post-harvest drying, thus thoroughly drying the kernel and cobs.

On the other hand, in the collection of cobs from the commercial corn production, besides

including different genotypes that may vary in composition, the main difference is a wide range

of water content depending on the time in which they are harvested. The harvest time is mainly

driven by kernel moisture, which is typically harvested below 30% moisture for the Corn Belt

(Pordesimo et al., 2005). In other words, if cobs are collected from corn lines for the production

of hybrid seed, the moisture is typically 10-12% moisture (cobs and kernel dried together in the

facility and later shelled). However, when the cobs are coming from commercial crops, the

moisture can be determined by the harvesting time of the kernel, in which its moisture will be

related to the moisture of the kernels. Indeed, large collection of cobs from commercial grain

21

fields will imply higher moistures in comparison to cobs from lines ranging from 20 to 55% w.b.

(Kaliyan & Vance, 2008).

The moisture correlation between the cob and the kernel has being addressed by many

authors (e.g., Pordesimo et al., 2005). Therefore, wetter kernel harvest due to environmental

conditions or farmer decision will entail higher cobs’ moisture. Thus it will encourage microbe’s

growth and material degradation if it is not handled correctly.