Crop consultant Bob Streit: Overview of Midwest harvest 2020

Key points in Bob's weekly report to clients: (1) Use early-harvest opportunities to accelerate stalk residue digestion and recapture nutrients. Biodyne's Meltdown shows excellent results. (2) Long-term management which enhances soil biology proved this year that healthy soil holds more moisture and preserves higher yields. (3) Continual loss of fungicide effectiveness is propelling firms toward more biological controls.

October 5, 2020  By Bob Streit — October has arrived, and shorter days of fall can definitely be seen and felt. It now stays dark until 7 a.m. and begins to get dark shortly after 7 p.m. Warmer clothing now feels good at both ends of the day. The leaves on our many trees are turning their brilliant shades of yellow, red and gold as the landscapes in Northeast Iowa and areas north look like a Normal Rockwell painting. It can be one of the most scenic and pleasurable times of the year.

If only we didn’t know what was coming next.

Harvest of our two major crops began in earnest two weeks ago and have been rolling without major delays since then. Running the machinery in muddy conditions became common in 2018 and 2019 as harvests were delayed by slow planting progress in both seasons. This fall, getting stuck and pulling out trucks and combines are not an issue.

Instead there were a few days where the Fire Marshalls in NW Iowa announced fire danger alerts for combines running in dry corn fields. Normally no one would pay attention to those officials, knowing winter is coming. But when the insurance companies are basing coverage on such warnings, it makes financial sense to heed such announcements. In Iowa, 46.9% of the acres are still in a moderate to severe stage of drought. Getting cover crops germinated, applying certain fertilizers, supporting pasture growth, doing several forms of tillage and getting 80% of the 5-foot moisture profile filled all depend on getting fall rainfall. That does not appear to be coming in the near future.

Bob Streit

The unexpected increase in grain prices has been welcomed by most crop producers. The bullish consensus numbers predicted it was bound to happen, but no one knew when or why it would happen. Part of the reason has to be that all USDA and NASS projects are based on models, and don’t register actual real-time cropping challenges that are always occurring.

The extreme heat that negatively affected crops clear across the Midwest didn’t spare any crop. The dry conditions were also felt in the latter half of the summer over about ten Midwest states and negatively affected grain fill. When the USDA figures continue to give good to excellent ratings to completely yellow or dead brown fields in early to mid-August, you realize those figures are not real. Those factors and the continued buying by the Chinese companies combined to lower stock numbers considerably — and the market responded.   

Field and Harvest Progress: By now most crop producers in the Midwest have driven through, seen in person, or seen pictures of the corn that got blasted by the Derecho windstorm in central thru eastern Iowa, plus the smaller Labor Day storm near Buffalo Center. Contrary to several Pollyanna-type predictions, the majority of the corn that was blown flat stayed that way.

Plants in many fields turned brown over the next two weeks. Others stayed alive a bit longer — until the drought and lack of water and nutrient uptake killed them. The big question at the time was how the insurance companies were going to instruct their adjustors on what constituted a field that was considered totaled versus one that had to be combined. Totaled fields ended up getting disked down or rolled rather quickly. Since those first two weeks, more of the affected farmers seem to have been told to do the best job harvesting their tangled messes and get what bushels possible to cover a portion of their damaged production.

As I see it, farmers like to be productive producers who always do the best job possible. Paul Harvey’s parable of ‘How God made Farmers to be Caretakers of Nature and the Land and helped to save and Nurture all Living Critters’ is greatly true.

Paul told it better than most of us could have. So there are growers who are now either being advised by their insurance companies or by the feeling expressed in the parable to try to save as much of that grain as possible rather than disk it under or let it go to waste.

Now if the Chinese are looking at their tea leaves and their long term predictors believe they have more seasons of drought coming, and we recognize that our moisture profiles may not get recharged, saving the extra bushels may be crucial to meet demand needs in the U.S. — and $4 corn would be too cheap.    

Soybean growers made great harvest progress last week. A high percentage of the beans south of Highway 3 have been harvested. Bean yields depended on two major factors: rains during the grain fill period, and soil health and organic matter levels.

Yields south of Highway 3 ranged from the mid-40s to low 50s with a few 60s. In addition, there was the occasional mid-60 to 70 bu. per acre. The better yields typically were generated on fields with a c/c/sb to a c/c/c/sb rotation and high nutrient levels. Adding in-furrow nutrition and/or biologicals, plus an effective and balanced foliar program added bushels. Foliars help combat dry soils, yet one needs water to boost seed size.  

There are now areas where corn harvest is progressing ahead of schedule. Those very short on moisture or where early maturity hybrids were planted, or places where the beans were not ready for harvest saw corn acres being combined.

Yields varied widely for a long list of cultural and cropping differences. Hail-damaged fields in western Iowa, lack of rainfall that caused early plant death, fields that were planted too shallow or did not tolerate the heat, damage from multiple insect pests, and flattened fields shifted fields into early harvest. There is no ‘average yield’ this year, just a range from 80 bu. per acre where rain was short, to 220-plus bu. per acre where rain fell all season.

One large factor influencing yields this year has been soil health. Long-term fertility and tillage/no-till programs that boost carbon and microbe population levels increase the ability to hold extra moisture, facilitate nutrient release, and increase drought stress. This promotes compounds for the plants to take up. Pesticides and fertilizers that act negatively to this need to be weaned from continued use.  

Fungicide use, corn rootworm (CRW) Traits: Several people have either asked about or mentioned that the conventional long-lasting fungicide they applied did not last as long as advertised. In the same vein there were cases where the CRW trait did not give the CRW protection that was expected. They were curious about what may be the cause of this, and whatever facts about the pathogen and its activity or insect biology may be the cause of the problem.

Lack of moisture and weather during the growing season can interact with biological systems. Years ago I visited Jim Olson, ISU extension entomologist who produced the CRW insecticide ratings. He had each set of roots (traited and non-traited) in piles behind the insectary on the afternoon I stopped to ask him questions. He commented that each pile's score — 1, 2, 3, 4 or 5 or some combination — varied by the degree of rootworm feeding. The score varied by what trait each hybrid contained.

An old ISU classmate of mine, Kevin Steffey, also published his study that each hybrid varied in its toxin level at growth stage V4 vs V9. It is also possible the cold May soils may have slowed the CRW hatch more than it did the plant growth. Thus egg hatch came after maximum toxin level occurred. Other people speculate that low moisture levels didn’t allow the plants to produce as much endotoxin as is normal. The debate is ongoing.   

As to why the different fungicides didn’t last as long as hoped for or as seen in previous years, several possibilities enter in:

1. Spray pilots tend to avoid making this application at tasseling time because of the "beer can ear" issue seen in Illinois a decade ago. Because the July thru mid-August period was quite dry, the leaf diseases incidence and threat were reduced. Right on schedule in mid-August, the early morning fogs and heavy dews became more common. Once the dews occurred, the leaf disease pressure increased and by then most or all of the residual period had elapsed. Southern rust then blew in, GLS multiplied in susceptible fields, and the combination can kill a corn field within ten days.

2. The residual period of a number of the three-way products simply did not last as long as in past years. Selection pressure is much greater when the pest completes more generations per season. This problem occurred in Brazil, Paraguay and northern Argentina as multiple generations of the pathogen and multiple applications of fungicide per season did a great job of selecting for more resistant strains of the pathogen.

This last issue — loss of efficacy with repeated use of products in only three existing families — is why we now see the major fungicide firms investing in endophyte, microbial or mineral based products they can tank mix to complement their current products.

This makes perfect sense since mineral-based products help meet the nutritional needs of the plants, thus do more than just protect yield. Such mixes, when developed, if they also provide systemic and curative activity, let a person time the applications better and also eliminate the need to apply products prophylactically in years when they may not be needed.

Currently the companies in the lead in the nutritional part of this equation are Spraytec (Brazil) and Phytobiotics (Germany). Yield trials with both products, where they were not destroyed in the windstorm, are showing they have performed very well. 

Soil Sampling: As you proceed with your corn and bean harvest, recognize that it is time to begin making plans for your 2021 crops. The place to begin making those decisions is to have a complete and updated set of soil sample analyses and results for each field.

Be sure to inform your analytical lab which tests you want them to perform. My advice is to have a portion analyzed for micronutrients and base saturation levels. Also select a few representative fields and have them analyzed via a Haney test as you begin to plan for the future. This can provide guidance as/if you choose to chase fertilizer efficiency using a foliar program and use materials with the greatest cellular uptake potential.

Stalk Degradation: In a season when so many ears may be left intact on the ground, getting the residue and kernels to decay quickly will be important. Make sure you consider this a critical step in disease management for all crops. There are a number of such products available to do this. We have seen great results with the BioDyne Meltdown product. 

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 Bob Streit and his partner Marv Mortensen are available at Central Iowa Agronomics