Assistant Professor, Soybean Extension Agronomist, Iowa State University

It is really difficult to imagine that after the flood in 2008 the next growing season would be as challenging as it was. Some would even say it was more challenging and I know for sure I will not forget it. The only good news from 2009 is that yields were fantastic. USDA is predicting that our average corn yield in Iowa is 188 bu/acre and our average soybean yield is 52 bu/acre.

It all started with a long and cold winter. Field work was finished in the fall and the snow did not disappear until late March. However, as soon as the snow disappeared we went into the field with one of the firmest seedbeds I have experienced here in Iowa. In fact, it was nearly perfect.

The first corn was planted in central Iowa around April 10. It was cold but because of the perfect seedbed it was difficult not to be out there planting. Looking at the data today many have wished they were planting that early since the yield results were unreal from these early plantings.

Soybean planting first started during the last couple of days of April. Soil was still cool, around 50°F, but it was not a problem with current technologies. The pace of soybean planting was slow and we were running behind the five year average until late May.

We did not see a lot of severe weather with tornadoes in the state but we had a lot of hail. Large areas in northeast and central Iowa were severely hit by hail. I have heard estimates that close to 1 million acres in Iowa alone were hit by hail with several hundred thousand areas complete destroyed.

The summer then stayed cool and with frequent rainfall throughout the growing season. Because of that, our two major diseases that thrive in cool and wet conditions, white mold and sudden death syndrome (SDS), became a huge problem in many parts of the state. In August, soybean aphids showed up in massive numbers like they did in 2007 and 2008. We thought the pest would only be a problem every other year but based on the new trend it looks like it’s an insect we will have to deal with every year. This fall, the migration of aphids back to buckthorn (wither host) was excessive so the chances that 2010 will be a large aphid year are pretty good.

Harvest pace was slow as well. Because of a cool summer, harvest was delayed between 10 to 14 days on average. Then, in addition to this, the month of October was wet which delayed harvest even more. Today, when I am writing this column on November 1 we still have 40% of our soybeans and 75% of our corn left in the fields. We have been forced to dry soybean or aerate them this year for the first time in decades. All corn needs to be dried as well and I would guess the average moisture content this year was around 22%.

So what can we learn from 2009? Well, first of all we cannot control Mother Nature but beside that I think that our choice of varieties that we are planting can still be improved. I am still wondering why we plant susceptible or moderate susceptible varieties do diseases like white mold and SDS in areas that have a history of these two diseases. December will be a good month to go through all the data from yield testing trials so these two diseases do not cause as much yield loss our farms as they did in 2009. As always, please do not hesitate to contact me if you have any specific question related to managing these two diseases or any other soybean management issues. Merry Christmas!

Palle Pedersen, Associate Professor, Soybean Extension Agronomist, Iowa State University

*Content Funded by the Soybean Checkoff