What a difference two weeks makes. The first week of June many acres of soybeans still had to be planted. Lots of acres of corn had just been planted and were beginning to emerge. Of the corn that had emerged most acres were only in the V1 to V2 growth stage. The clock was ticking and the days seemed to vary between hot and very windy or cool and cloudy. Now in the last weeks significant rains began with some regularity across the Midwest. The fears of a springtime drought seemed to be washed away for the first time in two seasons. Enough rain fell to restore a portion or all of the normal moisture profile. Typically, meteorologists suggest we enter the growing season with a moisture deficit of two inches of holding capacity so as to minimize the days being unable to do field work.
We had to chance to view many fields as we traveled thru my home territory of Mitchell and Howard counties over the weekend. What was beckoning me was as invitation to attend a class reunion in St Ansgar. Due to the virus suspending many scheduled events since 2020, the town hosted reunions for the classes of 1970, 1972, 1992, 2002. Finding separate venues for each celebration had been a challenge. It was good to see and visit with old classmates including several who have never attended in the past.
Crop Progress
Not everyone has received these generous rains as parts of western and NW Iowa have not been inundated in recent weeks. In central Iowa many points have received 6 to 8” in the past two weeks. There were still 5 to 15 to 20+ acre waterholes where growers had crops emerged but then have to wait days or weeks to determine how slowly or rapidly the standing water would drain away to provide the opportunity to replant crops which had perished. Even now the acres affected is unknown. Based on past experience corn and soybean plants can survive so many days under water. The main criteria seem to be the temperature of the standing water. If the water stays cool corn can recover from being submerged five to seven days. If the water is warm the corn plants can only tolerate 3 to 4 days under water. Submerged soybean plants are not as tolerant to the lack of oxygen and they die several days sooner. The plants are also more affected when covered with dirt. By June 23rd to the 25th we should be able to determine the acreage included in each pond. A light rain would help wash the mud off the bean plants. More time will be needed to see if root rots might kill those waterlogged plants. Thus, bean growers may currently have two challenges, submerged plants and/or hailed plants.
In both Iowa and Nebraska there have been problems with hail, with reports in western Nebraska of several storms where the stones were softball sized. Near Council Bluffs the hail damage was severe and replanting seemed to be the recommended option. One product new to most people is one called Soy fx. It was developed by a South Dakota biochemist/microbiologist for the purpose of helping bean plants survive major hail damage. Users of the product and hail adjusters have seen it regrow bud tissue even if all that is left of the plant is several inches of the main stem and the root. Word of this type of recovery is spreading among growers and hail adjusters. Apparently, the hail insurance companies have seen good enough recovery from hail damage if it occurs before July 20th that they give a major discount on hail insurance if this product was applied to the seed or the injured seedling. Truckloads of the product were shipped to hailed growers in western Nebraska and into the Avoca area. I am interested in the results as totally replanting at a later calendar date almost usually causes a yield loss. Keep your ears open for the reports from the affected areas. Having it in your tool box for future years may be very welcomed.
Yellowed Corn Fields
During our weekend travels we observed lots of corn fields that have reached the V4 to V5 growth stages. What we saw were fields that varied from being dark green and being in the late V5 to early V6 growth stage down to being V3 and very yellow. The % of fields showing the yellowing was much greater than usual. It was my guess that many of them had received only a small amount of preplant or at planting time application of nitrogen. Last fall when nitrogen prices suddenly skyrocketed growers either said N prices were robbery and it was going to be higher priced in the spring and paid the $1200 per ton of 82% or believed that prices would be more reasonable in the spring and delayed their purchasing. There were lots of sidedress rigs in the fields and a few anhydrous tanks seen on the roads. How many of those fields will be passable in the next two weeks and how many of them may not be?
One story going around was that Putin was needing cash for the fighting in the Ukraine and responded by putting up for bid among the larger fertilizer companies large amount of fertilizer that had to be paid in cash. Was this true?
One additional observation from our travels was that river and creek levels were very high and the water in them was very brown and carrying lots of soil. The erosion costs to those fields has to be very high. The dollar cost had to be major loss as topsoil doesn’t grow on trees. This is where no-till on rolling ground makes complete sense. Will strip till or high residue be the answer on flat ground or will a third crop offer that chance to maintain a green cover crop for operators who are wanting to lessen or eliminate erosion.
Our Visitor Last Week
We played host last week to a guest from Maryland who does documentaries and writes for Russia Today. He was born in Russia and started coming to the U.S. as a high school exchange student in Washington State. His home for himself, his wife and four kids has been in Maryland the last thirteen years. He visited this state eight to ten years ago when early planting had begun. He stayed from Monday thru Saturday and kept busy visiting farmers, interviewing them and gathering video from which he will compile two documentaries. A question he was hoping to ask and researching was how U.S. farmers and their cropping plans were affected by the lack of fertilizer shipments from Russia. My response to the question was that supplies were tight and very expensive in 2022, but that inputs for the 2023 season may be more difficult to source. This has growers apprehensive. Now the movement to regenerative agriculture has been growing. Those participating are buying and applying many fewer lbs. of each nutrient, and were also planning to rely more on microbes to make the previously applied fertilizers plant available. Using N fixing microbes to pull N from the 76 or 78% N in our atmosphere has also been increasing in scale. As growers pick thru the N fixing microbial choices and see success, less purchased N may be needed. When Putin resumes offering fertilizers to both N and S America, growers here may tell him we don’t need his products anymore and he may end up shooting himself in the foot.
The Main Task at Hand
The main task at hand for farmer or retail sites the last week has been getting the corn acres sprayed for grass escapes and emerged broadleaves. With the ample moisture many areas have and the 90+ degree temps that corn will soon be too tall to spray with short ground driven equipment. In the fields I have scouted there were typically many 1 to 3” tall waterhemp along with similar sized or larger giant ragweed, velvet leaf plants, lambsquarter and other plants. This took precedent along with getting any late N applied as most post broadleaf products need to be on by V5.
Next on the list of tasks to do was spraying the bean fields with the second shot of residual products and for escaped broadleaves. This was a tougher task due to almost constant, strong winds that seem to be with us on most days after 8 am. This required most operators with high clearance sprayer to be loaded and in the field by 5 am to keep covering the acres. The June 20 th deadline for any Dicamba date created urgency for all applicators.
Insect Issues
The insect control task that may be an issue would be to get any post application for control of corn rootworm if traits are doing the job. Where the main risk of occurrence may be fields planted to corn where there were many larger waterhemp attracted egg laying female rootworm beetles. This unenviable task is best done crumbling rootballs over a black piece of tar paper and searching for the small white larvae with blackish heads that start crawling away.
2022 was due to be a peak year for the European Corn Borers. So far, they have not materialized as the normal shotholing of the leaves in the whorl. Hindering them had to be the small corn plant size. The small stalk diameter does not offer them a decent host plant to live in and feed on.
Tissue Testing Needs and Formulating Tar Spot Treatment Plans
Now that most corn plants have reached the V5 growth stage or will soon, the plant will have to be making its own sugars and pulling in minerals themselves. It is time to pull tissue tests and have them sent to a testing lab to see which if any minerals are low and should be applied foliarly to fill any deficiencies. With V5 to 7 plants cut off the entire plant a few inches off the ground, place in a vented bag, let dry and then send to the lab of your choice. Most labs will be returning your analytical report via email within 4 or 5 days of you sending them in.
Because we did an analysis of tar spot (TS) affected plants from a tar spot plot to figure out what TS was and why it was occurring, we know to advise corn grower to identify deficiencies of zinc, copper and sulfur and respond if needed. If you have not yet looked at our findings go to our website www.centralIowaAg.com and look under “News” – “Educational Articles”.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.