homepage logo


By Staff | Sep 27, 2013

The fall season has arrived and is or soon will be time to start harvest. This is typically a time of great hopes and dreams, where we want to get done with each field, but never want to quit hauling grain into the bins or the elevators.

This year a common thought among many growers is that they just want to get the season of 2013 over with and then forget about it.

Everyone fought the good fight, but things just did not cooperate. Everyone did most of what was humanly possible, but the weather needs to cooperate, frequent rains need to fall at the opportune times and temperatures need to be warm at the right time and cool when the plants need it.

Just as going into the 2012 harvest and final yields were extremely unpredictable, the same goes for this year.

The big difference may end up being that most of the corn last year was planted early, so when it died early a much higher percentage of the grain fill had been completed.

We also had much more rainfall in the soil profile and the roots grew deep to access it. This year those things did not happen.

There are, or will be, combines running in some of the earlier planted corn this week, as well as in some of the early planted and early maturity beans.

Very little yield information is floating around, which is typically a bad sign. The operators now getting 150 bushels per acre may now feel bad, but could find out that that figure may constitute an above-average yield.

We will be collectively smarter in two to three weeks after more growers get their combines running over more acres.

Corn yields

I am hearing of some very good yields, 225 to 268 bpa yield in central Illinois where they caught timely rains, but no one seems to know if those are monitor peaks or whole field yields.

The guys who reported those sizeable numbers also remark that a pair of 2- to 3-inch rains fell during the grain fill stage and the kernels then plumped up notably.

In irrigation country they always say that each inch of rain should be worth about 12 bpa. If that axiom is correct, then those 5 inches of rain that passed over Iowa and into the state to the east could have contributed 50 to 60 bpa if the plant’s tissue was still green and had moisture available.

I have also heard of corn yields as low as 50 bpa, and then what may be a large category where corn yields are 120 to 140 bpa.

One of the bigger reasons for this yield shortfall has to be lack of moisture to form starch and protein to fill the kernels on the ear.

The same issue of plants running out of moisture is common, as plants having to survive and thrive through as many as 75 days of dry weather had to give up the ghost without enough water to keep filling ears.

Based on what I have seen in my travels there will be acceptable yields in extreme western Iowa, eastern Nebraska, parts of northern and northeast Iowa. There will be big difference between genetics and resulting plant health, as well as moisture holding capacity of the soil in each field.

Ear size varies tremendously. Planting date, amount of fertilizer applied and stayed put, and how well those plants rooted were all important parameters that controlled how final yields will turn out.

Soybean yields

Guessing final yields and doing so accurately can involve several semi-complex formulas. All have to be cognizant of pod count.

Late planting leaves less time to form flowers and pods, branches and pods, grow roots and support the nitrogen fixing bacteria. The optimists hung on for a long time, hoping to catch one substantial rain during mid-August through early September and few received it.

Over the state we will see some mid-60 to low-70 bpa yields, down to yields that fall into the single digit category.

Ten bushel per acre yields are not commonly seen, but based on pod counts a number of late-planted fields appear to be heading to produce at that level.

Now those beans looked promising, but when the plants got dry they shrunk considerably and farmers may have a tough time getting them into the cutting bar.

Changes in 2014

In the two field days I attended last week, and the many plots I have stopped at and walked, green corn is not common.

Fewer days of green tissue to form sugars and starches leads to a poor starch fill, and consequently poorer stalk quality.

Each grower needs to scout the different varieties in each field and see which ones are getting softer and may have a tough time standing through until harvest.

Then start the combine where the risk of lodging is greatest.

When each field day visitor inspected the green corn their first thoughts zeroed in on the ear size and expected yields.

While theirs at home were likely brown and dead, these plants were still green and still filling.

What was touted as the recipe for maintaining plant health consisted of providing good base nutrition and supplementing it with specific foliar nutrients that both fed the leaves on the clogged up plants and added to grain fill.

Numerous nutritional products were included in each of those late post applications. Some were meant to control Goss’ wilt, while others were supposed to keep the plants internal cellular processes humming along.

With the information that was given to people who asked good questions, they should be able to map the path and products they need to use to reach the level in plant health and energy needed to maximize yields.

Soil sampling, testing

As soon as half of the beans are harvested each grower should know which fields are in need of soil sampling and lining up the person to complete that job. Be sure to sample to a pre-arranged depth, such as 6 to 12 inches, and then pulling 12 to 18 cores that are then mixed and sent into an accredited lab.

The results should come via e-mail and those results have to be compared to the results of fields that were treated with different levels of fertilizer to test for a regular response.

Good luck with getting the corn completely mature and starting on harvest.

Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143.

Please Enter Your Facebook App ID. Required for FB Comments. Click here for FB Comments Settings page