Frost Damage and Corn Silage Options

The recent freezing temperatures essentially stopped corn growth for most of Kentucky. Farmers that had corn planted late for silage are wondering if the corn crop is still suitable for silage. The following is a brief summary, mostly from AGR-183: Late Season Frost-Damage to Corn for Silage.

Corn will ensile well at moisture levels less  than 70% for upright silos and less than 75% moisture for horizontal silos. Corn harvested at 62% to 68% moisture (late-dent stage) is ideal for ensiling.

The typical whole plant moisture concentration for corn at various growth stages is as follows (Lauer, 1999):

1. R3 (Milk Stage), 79% whole plant moisture
2. R4 (Dough Stage), 75% whole plant moisture
3. R5 (Dent Stage), 70% whole plant moisture

So, if the corn crop was in the dent stage, then the crop is most likley suitable for ensiling. Frost damage on corn that is above 70 to 75 percent whole plant moisture will result in poor quality silage, souring and low animal intake (Lauer, 2009). Ideally, the plants should be allowed to dry down in the field to proper ensiling moistures. The recent temperatures have not been conducive to field drying. As a result, some of the plant material will be lost while we wait for it to dry down.


Waiting to harvest frost-damaged corn will improve silage quality but will decrease dry matter yield. Producers must balance between expected yield losses and quality gains deciding to harvest.
 
For more about harvesting frost-damaged corn for silage, consult AGR-183.
 
References:
Lauer, J. 1999. Silage Drydown: How is it Progressing? Wisconsin Crop Manager: 6:140-141
Lauer, J. 2009. Sampling Corn Silage Fields to Accurately Determine Moisture. Agronomy Advice 28: 47-72
Lee, C.D. and J.H. Herbek. 2004. Laste-Season Frost Damage to Corn for Silage. AGR-183. University of Kentucky.