Whether you are a farmer or not, this spring and summer weather so far have been conversation starters!!  From high lake levels and creeks and streams to the present much lower levels, it has been a story of contrasts.  

While I record rainfall and snowfall for Blue Mounds township, I don’t record temperatures.  I don’t think anyone would dispute the fact that this growing season has been warmer than normal.  I am on the weather emails from WCROC (West Central Research and Outreach Center) at the east end of Morris.  

Their station is about 23 miles from my farm south of Starbuck, so it interesting to contrast their precipitation summaries with mine.  While precipitation can vary a whole lot depending on how the thunderstorms and snowstorms deposit their production, temperatures probably don’t vary a whole lot in that 23-mile distance.

On the 10th of August I got the 3-month summary of weather for May, June and July.  While statistics can be terribly boring, I will attempt to compare temperatures, rainfall and growing degree days (a measure of temperature and time [in days]).  It is a useful benchmark for comparing growing seasons for different years.  One definition from an internet search is “The base temperature most often used in calculations is 50 degrees F (10 degrees C) because it is the temperature when active growth begins for most organisms.”  For instance, corn, the most prominent farm crop in Minnesota, does not germinate very well under 50 degrees.  So, here goes with the 3-month comparisons with WROC and my farm:

*May: High temp was 82 degrees on May 28.  The highest temperature recorded in May at WROC from 1886 to 2021 was 106 on May 31, 1934.  Precipitation for the month totaled 6.14 inches, which is 3.17 inches above the average of 2.97 inches.  I had 7.79 inches at my farm (compared to .86 all of May, 2021).  Of particular interest to us farmers is that the GDDs were 292, compared to the average of 311.  So those below average, combined with very late planting, resulted in slow growth. Most corn around here was planted in late May and early June, compared to most years when planting corn happens in late April and EARLY May.

*June: High temperature was 99, on June 20.  Highest temperature ever recorded at WCROC in June was 109 June 25, 1988, and June 28, 1931.  Precipitation for the month totaled 2.08 inches, 1.92 inches below the average of 4.0 inches.  At my farm I had 1.36 inches, and 1.84 the same month in 2021.  

Interestingly, June is when the GDDs really kicked in big time.  WROC accumulated 562 GDDs, compared to the average for June is 503 (1976 to 2021).  For May and June, WROC accumulated 854 GDDs, while the average is 814.

*July: High temperature at WROC for the month was 96 on July 19.  Precipitation totaled 1.64 inches, 2.01 inches below the average of 3.65 inches.  (I had 1.21 inches at my farm, and 1.54 inches in July of 2021).  At Morris, they accumulated 714 GDDs in July, compared with the July average of 631.  For May, June and July, they have accumulated 1568 GDDs; the average is 1445, 123 GDDs above average.  Last year they recorded 1633 GDDs, 65 more than this year.  But the big thing for our area is that this year we have subsoil moisture from the very wet spring, while last year we had nothing extra in the subsoil to mature our crops.

A little personal story from this July:  The evening of the 4th this year I walked into my first-planted corn field (planted May 18, much later than normal for me).  It was belt high on me on that date.  11 days later I walked into the same field in the same area, and the top leaves were way above my head (no tassels yet).  So that corn had grown about 3 feet in those 11 days.  Credit the high GDD’s for that!!

About this time of the year, I usually go into my corn fields and make some yield calculations.  I go into several areas to get some idea of what the yield may be at harvest time.  But looking at the developing cobs, at this point I can’t determine accurately how long the harvestable kernels on the cobs may be.  I count the average kernels around (usually 16-20, generally even-numbered), then the number of kernels of length.  It’s hard at this point to determine if the kernels at the top end of the cob will be harvested, or if there will be “tip-back” and the kernels at the end of the cob would be unharvestable.

Regarding soybeans, they are much more difficult to analyze for yield.  Experts say that corn is made in July, when tasseling and silking happens.  But they say that beans are made in August, when blossoming occurs and pods are formed and filled.   

At this time in the growth and development of soybeans, we are on the lookout for insect pests.  Most years, we have to apply insecticide by ground spraying or by air.  We look for aphids under the leaves and on the stems of the plant.  The common trigger for treatment is 250 aphids per plant.  So far none of mine have met that threshold.  Last year, with the extremely dry conditions, we had to spray for spider mites instead of for aphids.

Last weekend (August 6-8) I had 1.1 inches of rain in three different little showers.  Thankfully, it came gently, without much erosion or runoff.  That was desperately needed; we will see how important that weekend rain was at harvest time in October-November.  

What would be a major disaster this growing season is if we were to have an early frost.  In 2021 I did not record any frost in October, so that was of no consequence for the crop harvest.  But what was of consequence, was the rain last fall.  Here I had 14.6 inches of rain August 1 to Nov. 1.  That made for a very messy harvest.  

I looked back in my records for ’19 and ’20 and found no records of frost in those particular harvest seasons either, so there was nothing consequential.

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Please contact David Tollefson with thoughts or comments on this or future columns at: adtollef@hcinet.net