December usually finds me reflecting on the year that was. What worked, what didn’t work, what remains a mystery, what should have had more focus, and what really doesn’t matter anymore. For the vast majority of people who are not crop farmers in Huron County, December doesn’t hold the same definite ending. But for those of us who are, it is the time when we get our yearly report card. 

We start thinking about and actively harvesting in July. We have a small reprieve and then are back at it mid-September. When we finish is anyone’s guess – but somewhere between the beginning of November and the end of December. OK, yes, one year it was January – but we don’t talk about that. 

In those years when harvest drags on into the late fall, it seems like we jump out of harvest mode, race to get all the equipment cleaned up before things freeze rock hard, and then tackle the mountain of paperwork that has built up while my focus was on keeping the wheels turning outside. Before the dust has even settled, we are into analysing the results of our cropping season so we can order and pay for our seed for next year. While the early December deadlines seem like a cruel punishment after a tough harvest, it really is the best time to make those decisions when the details are still top of mind.

Every year it seems a little more complicated. Corn varieties are evaluated on many factors including yield, moisture, bushel weight, and resistance to an ever-growing list of diseases and pests. The Ontario Corn Committee posts their trial results comparing hundreds of corn varieties that have been grown across the province. The plots are grouped according to the corn heat unit (CHU) areas and can be found at their website at https://gocorn.datahome.ca. Crop, or Corn Heat Unit, is a measurement of cumulative heat over the growing season.  This takes into account the fact that corn doesn’t really grow much if the temperature is below 10 degrees C or above 30 degrees C. https://www.grainews.ca/columns/wheat-chaff/growing-degree-days-versus-corn-heat-units/.

Then comes the glossy brochures from all the seed companies. Each variety has its own genetic profile, then may have different traits inserted. These traits provide protection from lots of different things including corn rootworm, western bean cutworm, and a variety of funguses; the list grows longer every year as more and more challenges move into our area. Tar spot is the newest fungus to take up residence in Huron County. We usually get a preview as most of these things start in more southern regions and move our way. We still battle the old things, which are always figuring out ways to get around our methods of dealing with them.

We take all of this data, including what we found on our own farm, put it together and make our selections. As we have increased the number of CHU over the years, the group of varieties that we consider suitable for us has also changed. Varieties requiring fewer CHUs often have lower yield. Varieties requiring more heat can produce more corn, but they also take longer to mature, which can result in a disaster if we get an early frost. They also tend to be wetter at harvest, which increases the cost of drying. Leaving corn out in the field to dry down also increases the risk of developing fungal diseases, which can mean bigger discounts when it comes time to sell. 

The biggest wildcard in all of this is the weather. While there are long term trends for both heat and moisture, there is a big variation by year and even bigger variation by month. For most crops, there are windows of growth where having rainfall can make the difference between getting a bumper crop and getting less than average. Humidity, wind, sunlight, rainfall, and even dew can play a big role in the development of fungal diseases as well as insect growth and development. 

The staff at Brussels Agromart puts together a very interesting annual summary of the weather. People who comment on how Canadians love to talk about the weather would be amazed if they saw how many ways we can slice, dice, and compare rainfall and CHUs. I don’t know how long Brussels Agromart has been providing their clients with this information. I have a “Local Plot Data” book from 2005 with two charts on the back page – one is a summary, by month, of CHUs, including a column for the 1989-2003 average. The other is a summary of rainfall, by month, including a column for the 15-year average.

The “2023 Year in Review” has almost double the number of pages, including 24 pages of weather data. I keep these books, as they provide a very interesting snapshot of the year that was, as well as a comparison over the longer period that helps us predict, at least a little bit, where we might be heading. For instance, the 2005 book contains the average CHU for the period from 1989 – 2003 of 2555 CHU. The 2023 book contains the average CHU for the period from 2011-2022 of 3056 CHU. Doing the math, that means over the past 33 years, our area has increased the CHU by 16.4 per cent. 

We don’t know if this rate of change will continue going forward. Maybe the best we can do is to be aware of the trends in order to manage the changes as they come our way. We need to look at the fine details for our day-to-day decisions, but occasionally stepping back and taking a bigger view can help us make better long-term decisions. ◊