The month of July is now over 50% complete. The number of days where the high temps reached or exceeded 90F has likely matched or exceeded any count from the 1930s or 50s. Any temps over 84 F exceeds most peoples’ comfort margin, regardless of the humidity levels. Looking at the 20 and 30 day-forecasts by different meteorologists, several predict numerous daily highs near/over 100F in the western cornbelt. In 2009 (?) we had few days in Iowa in excess of 90F. The moisture front heading straight for Iowa this past Sat night would have given a welcome drink of water to the many corn fields nearing their reproductive stage. It changed course. If you get to brave the heat keep your ice water jug handy.
I was asked to spend a few days with a tillage and planter consultant who was wanting to provide guidance to a few of his S Dakota clients who they and their crops endured two derechos in a one-month time period. There was a considerable amount of damage to sheds and barns from the first storm. The affected farmers and business people immediately went to work fixing the damage and replacing destroyed equipment. Then the second one hit a few weeks later in roughly the same area and did the same sort of damage. Just as in our derecho what the insurance companies guaranteed customers as replacement cost was not what the insurance companies followed thru with as replacement cost. The damage and cost to repair and replace equipment is overwhelming to many operators.
Dakota and NW Iowa Derechos
I had never seen fields where all of the worked soil and nutrients in it just blew away and were lost. A person would normally assume that soil from Farmer A, 40 miles to the west would contribute their soil to Farmer B, while Farmer B’s soil would blow 40 miles east to Farmer C in hop scotch fashion. Not! It was just gone with the wind. It was apparent that metal structures were more affected than older and dilapidated wood structures. There were magnetic features to these storms. Seasoned people who recognized this drew their own conclusions as to how such storms magnify in ferocity so quickly. Pictures of the clouds moving in from the west and northwest looked like those taken of the 2020 storm. For those and articles on weather check out our website under “News” (www.centralIowaAg.com).
Their corn was mostly in the V10 to V11 growth stage where the roots were torn lose and the plants goose-necked 8 to 10”. Their soybeans were slower in developing as ours have been in the eastern 2/3rds of the state. Many of them were at V5, V6 or V7 and showed no signs of flowering. I informed them that we are seeing that foliars containing various carbon chained sugars in energized water enhance flowering. The research professor in California who conducted a replicated study for a major Ag firm had recommended that course of action to be taken when flowering is delayed. I also recommended they use products that would promote additional branching to compensate for their delayed development.
I did get a chance to see fields where the Soy Fx had been applied to soybean plants after it suffered major hail damage. The large stem pockmarks from large hail impact were very visible and should have killed many of the plants. The product had fostered great regrowth of tissue and new growing points in the 2 to 3 weeks since application.
Corn Issues
It is often said that the sins of spring often don’t show up until the summer. I was present when deep root digs were done within the corn fields in SD. By digs I mean using several long spades and digging down 3 feet and pulling up the entire root ball. If the tillage implement, fertilizer applicator, planter or other equipment created a compaction layer that had not been fractured, the root growth was affected and often limited in growth. That subsequently restricted the moisture uptake of the plant during the season and could open the door to these ‘flash droughts’.
Insect Issues
As of this date several different insects have made their initial appearance in parts of IA. The gall midge (SBGM) flies have been detected in monitoring traps. A consortium of researchers from NE, IA, SD and MN are partnering to divide and develop the answers to the questions about SBGM. The team is working to sleuth out facts about: predictive modeling: as to how to scout for them; GDU requirements for their various growth stages; develop a strategy for growers and a list of products (natural, biological or hard chemistry) that would be workable program for farmers that have seen the pest moving into their field margins. A question that needs to be asked is ‘Are the flies targeting nutritionally deficient plants’. Insects are often the garbage cleanup crew.
Aphids were spotted early in MN and SD weeks ago and have been confirmed in several NW IA fields. In a droughty 2003 they caused major losses in heavily infested fields. Sap formed by the plants is used to form sugars and yields. In dry years each gallon of sap is needed by the developing plants. There might be two methods of control. A newer product from BASF that is safe to pollinators, yet effective in limiting feeding, and affordable was introduced two years ago. Sefina works by making all the aphids walk around twitching instead of feeding. Safety to applicators and beneficial insects are selling points.
One wise crop advisor with a background in plant biochemistry, physiology and fertility suggested that soybean growers look at recent tissue tests and check on the moly and manganese levels. If those levels are low the plants are rendered attractive to insects seeking simple sugars and NO3-N. The Mn allows the plants to process the simple sugars into carbohydrates and the Moly allows the plants process the NO3-N into proteins. Moly is essential to the plants and its ability to make efficient use of nitrogen.
The UNL light traps located across the Missouri River in Nebraska west of Omaha (Mead, NE) and west of Sioux City, function by attracting night flying insects (beetles and moths). By identifying which species are flying they assume that they are laying eggs that will hatch within a certain time period. The tough job is then to scout for the larvae which may be feeding on your crops. Dr. Phil Calahan, renown entomologist at the U of Florida, proved that insects navigate, find their food and their mates via highly sensitive radar in certain climactic conditions. Crop scouts and alerted grower needs to discern which of their fields hold plants that have put out the welcome mat for the pregnant females.
The most recent black light catches suggest that this may be a bad year for western bean cutworms. Virtually none of the traits that control European Corn Borers are effective against WBC. The females visit several whorls and lay triangular shaped egg masses which can only be spotted from above or by pulling the tassel down to shoulder level. Doing this in 100+ degree would best be done with a drone carrying a very precise camera with magnifying capabilities.
The last insect to mention would be CRW. In dry years plants need all of their roots to extract moisture and minerals from the soil. They also have to anchor the plant if strong winds hit. Fields that are most at risk are those planted to beans in 2021 infested with lots of tall, waterhemp escapes loaded with pollen in the fall attracting hordes of egg-laden CRW adults. With fields starting to show tassels the beetles will be flying shortly. Expect some smaller company to develop a fungal species that will devour the eggs or an attractant that will use miniscule amount of a hard or natural insecticide to eliminate the egg laying. This worked in the past with the Invite program using bitter melon juice as a bait.
Athena Muskmelons
We are still trying to figure out what is wrong with the cantaloupe. A second state and grocery chain has similar tasting melons with the same aroma of acetone, or finger nail polish remover. A friend and mineral expert who attends national melon conferences offered a few clues and possibilities. I foresee dried samples being sent to a diagnostic lab for analysis. What might we find using enhanced ICP?
Tar Spot
Once the corn plants encountered regular dews and approached their reproductive stage, the Tar Spot sightings increased across the Northern Midwest. What was the common response? Was it to determine the cause of the problem or immediately start applying fungicides. That sounds like most of modern medicine. What has occurred in southern Brazil and Paraguay by 2017/18 is likely to occur here. Nature always wins, so it is best to recognize the shortfalls of any control program and recognize that nature has already provided an answer. Through the work of a small group of dedicated scientists the best methods of controlling pathogen fungi were sleuthed out forty years ago.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.