Between the Rows: An End to A Long Year
Greg Roth
Department of Crop and Soil Sciences
Penn State
January 2000
I'm sure the 1999 growing season had as many days and hours as previous seasons, but for many of us it sure seemed like a longer than normal year. For many Mother Nature threw a few curveballs that resulted in some dreadful corn crops being produced around the state. Fortunately, this kind of season is a rare occurrence that hopefully may not reoccur for the remainder of your careers.
I thought it might be good to revisit a few of the issues we ran into this summer and review what we learned.
Many folks were faced with making decisions and doing things that they had not done before. Cutting silage in early August was one of those decisions.
One issue that I was concerned about was the regrowth potential of corn that was severely drought stressed. Generally it seemed that corn that had pollinated and had some ears was able to show some recovery after the rain began in some areas in mid August. Corn that had no ears did not seem to recover.
Corn that was chopped for silage often was wetter than it appeared and their appeared to be a fairly narrow window between too dry and too wet. Once the rain began to fall and some fields greened up, then the corn began to take up moisture again and become very wet. Some reported to me that the density of the silage chopped from drought stressed fields at the right moisture was lighter than normal. A key ingredient to success this year was to monitor moistures carefully and pick and choose fields as they reached the desired moisture level of 65 to 70%.
I visited some producers who were continually monitoring moistures during harvest with reasonably good success. Many who did not ended up with juicing silage. There is no substitute for testing.
The forage quality of the drought stunted silage was reasonable, but not great. Energy levels of this kind of corn were about 80% of normal. Nitrate levels were generally elevated but within manageable levels. Potassium levels were elevated across the board, with high levels in some cases. This is because potassium is taken up early in the season and then is diluted in the silage during grain fill. When grain fill is limited, then potassium levels are not diluted. The fiber digestibility of this silage should be good, because the plants generally do not produce as much lignin under drought conditions.
By late August I began to see lots of corn borer and earworm damage to the ears in many Southeast Pa. fields. With this there seemed to be an increase in the levels of ear molds as well. I had several samples of ears run through our Diagnostic Clinic and almost all had evidence of Fusarium and Aspergillus. Fusarium is capable of producing a variety of mycotoxins and Aspergillus can produce aflatoxin. The presence of these molds, the low density of the silage this year and the difficulty of getting the moisture right at harvest all suggest that we may have more mycotoxin and aflatoxin problems than normal this year.
There also is lots of ear smut in many of these drought damaged fields, and this is typical of drought damaged corn. Generally, smut does not result in mycotoxins in the silage or grain but it sure is ugly.
I also anticipated more stalk lodging this year and my trip through the southeast part of the state last week confirmed this is happening. It appears to be happening due to a combination of both root and stalk lodging.
Grain harvest is underway in some areas and the preliminary reports in drought stunted areas are that yields are variable, as expected. In some areas the recovery from the drought has been more than expected but in other areas there has been essentially no recovery.
I suspect we may see more harvest losses than usual this year with the small ears in many locations. Drydown seems to be fairly rapid in most areas due to the accumulation of heat units that we had, but I am finding that there is some variability in drought stunted fields where you'll have some corn that was delayed in maturity due to the drought and some that has developed well.