The summer and season is continuing at a very rapid pace. In most cases the corn crop in most places reached knee high or taller by July 3rd. In fact, there were tassels poking up in a number of commercial fields with silks soon to emerge. In my gardens the mid-April sweet corn tasseled in June. When you might take a drive across the center and far reaches of the state now it might look like all is well because it looks good from the road. What does not show up live but could prove to be the hindrance to great yields is the lack of subsoil moisture. Now that the corn crop soon will have to endure the gauntlet of forty straight days of above normal temperatures our inability to get more than .5” or .75” could be the crop’s downfall.
Unfortunately, the prayers for rain in SE Iowa, parts of Illinois and Missouri received rain, but along with it 100 mph winds that pushed the plants down creating questions about what to expect from the corn crop, plus what, if anything, they could do to prepare for a long harvest as going thru those downed fields could be quite a challenge. There were a few management suggestions gleaned from the blown down corn years such as 1987 east of Carroll, 2002 west of Marshalltown, and the derecho crop of 2020.
I received a few comments about my last article where I mentioned weather manipulation experiments and equipment installed plus patents awarded for such facilities. I did a bit more searching the arena of DEWs, or directed energy weapons. This is what our meteorologist said was involved after I emailed him a picture of the funnel she took ass it swooped down in her Cedar Rapids neighborhood in 2020. Outside forces were in play in his opinion. So now we just had the 4th major derecho of the last three years. Or was the number more like 8 or ten if we include those in Nebraska, KS, the two in NW IA thru MN and S Dakota. Winds of 100+ flattened corn fields from southeast Iowa, thru Missouri and Illinois before crossing into Kentucky. The difference in the latest storm is that the top 2 to 2.5” of soil did not get carried away and dumped into the Atlantic. An old acquaintance from California who had zero college education, yet builds serious lasers for the military, private companies and universities show me demos of what his lasers were capable of. One of them was enhancing the severity of storm systems. The second was of crowd control by either turning up the heat on crowds of disassociating the molecules of any two or four legged pests.
So far, the season has progressed like a replay of the last five in that we had to deal with cold and wet conditions early which morphed into strong a strong and not drought. So far, the corn crop in much of Iowa looks very good. Much of it being head high or higher by July 4th. The bean crop seems to have endured a tumultuous growing season where growth has been slow and a lot of fields don’t appear to be on target to cover the rows.
Derecho Questions
What we learned from the windstorms of those mentioned storms is that there can be surprising good yields harvested from flattened fields. The variables in each storm depended on the timing of the event. Growing back upright can be done as long as the corn has not reached the VT stage. If the crop is past tasseling growing upright sucks away energy meant to be expended on the tasseling and silking phase. In 1987 there was a major windstorm in late July and lots of 85+ F days after the storm. The lack of ventilation and rain led to the grain cooking on the ear. In 2002 or 2004 they had a big wind in late August. The rest of the year stayed cooler with light winds every day to keep the plants cooler and good grain yields were harvested. In 2020 the large derecho with winds in the 100 to 142 mph range flattened or broke off many plants. The first impulse among farmers affected was to destroy the crop and take the insurance money. In the end if they combined slowly, or rented or bought light footprint aluminum heads (Maya) which they found they could pick up most of the ears. The grain from those ears was of good quality and it commanded a good price in the following marketing season. Many affected farmers later kicked themselves for destroying what was going to be a large sized corn crop. Bushel in the bin in a tight grain year are always nice to have.
Much of the area which was most affected by the wind event was also affected by severe drought. If the man or woman in charge had promised to send 4” of rain the growers would have been overjoyed. Their crops had already endured 6 to 8 weeks with no rain and prospects were thin. But the devil was in the details, as in 4” of rain accompanied by 100 mph. Would they still take the rain? At this point that is an unknown.
If the temps remain hot and the humidity levels within the canopy are high, expect more leaf diseases and quality issues. My recommendations then would be to fly drones over the flatted fields flying on amino acid chelated products. With long residual and curative action, they should keep the plants healthy and alive while staying productive. I have to wonder if the products sold as Respite of Phonix would benefit the crops by lowering canopy temperatures.
Soybean Issues
Here we thought that by applying biologicals and foliars having IDC on beans was a thing of the past. I did see that Y-dropped BioDyne completely rescued two quarter sections of seed milo down near Amarillo, TX. Including Sideophores, which are microbial exudiates, are generally highly effective in freeing up minerals and turning crop leaves green again. There are still a number of fields where we are hoping to green up SB fields where IDC yellowing was bad. We also have to investigate which minerals may have been chelated by carryover from last year’s corn SDHI herbicides. Bleaching tells us that magnesium was being affected. It is the key component of chlorophyll.
With many fields reaching R1, when flowering begins, remember that White Mold can become a very damaging pathogen. Those little mouse-dropping appearing spore cases have already formed the small birds-nest appearing fruiting structures and will be releasing the spores, targeting the flowers where the petals are abscising. Low lying fields, areas near streams, fields shaded with lots of trees and any areas with limited air flow and high humidity levels are most at risk. The disease can quickly drop bean yields by 25, 50 and even 75% in the worst areas. The best remedy I have seen are the zinc and amino acid based product in systemic chelator mix.
Corn Insects
I have been watching for European Corn Borer feeding and until recently had seen very few. UNL black light traps were not detecting any moths. On one late evening trek I suddenly ran into lots of moths which were making my windshield greasy. Those moths were not ECB. But I was still seeing feeding scars in the corn whorls, but very few larvae. Then I began to see 3 to 4 Grape Colapsis beetles which were doing the feeding.
I was also finding small spider mite colonies that were just getting established. If conditions continue as hot and dry those could continue to multiply. Their main pest is a fungus which increase faster in cool and moist conditions.
Corn Diseases
Until now the hot and dry conditions did not favor any pathogens which need dew on the leaves to become established. However, once the corn reached V10 to 11 I began seeing lots of a Clavibacter caused lesions to form. These appear as caramel colored watery lesions on the lowest abscising leaves which are now being shed. What happens is that the bacteria progressively plugs the plumbing tissue as the season progresses. The B14 based hybrids are the most susceptible to it and to early death. A number of us who believe that proper mineral nutrition is the key to good plant health, and have the visual proof to it, believe that this plugging creates the mineral deficiency which causes the normally benign fungus to spit out the manganese oxide onto the leaves leaving the brownish lesion on the leaves. Any time a 120X normal Manganese level is reached a more thorough examination is called for.
At last count Tar Spot has been confirmed in a wide area of the Midwest. More states are included in this list by the week. There is only one new product that I would trust to treat it that is not based on halide chemistry, which is deadly to beneficial soil fungi. There is only a small supply. Check out our website for the literature on it.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.