What a summer and what a growing season. Does anyone know what to expect next? Actually, keen observers recognize that up until now it has been mostly a cookie cutter repeat of the last three seasons. Unseasonable warm in early to mid-April, then it dropped into the freezer for two to three weeks, and then when it did warm up temps were in the 90s right away. Then hot weather thru much of June through early July. Thru the season no major rain front move thru the state and many parts of the Midwest saw rainfall totals in the low single digits. If rain did arrive it was thru narrow ran bands that slipped thru the standing high pressure blocks set up across eastern Nebraska and Kansas by who knows who. Our major row crops and pastures have been teetering on the edge of a cliff, leaving us wondering how they can survive as long as they have with scant moisture supplies from above and nothing down below. The one thing we have not endured, and one hates to mention it, is a repeat of the Aug 10th 2020 derecho.
It’s Show Time
I am late in mentioning it but it is the time of the season when many local and Midwest Field Days are held. Field Fest in Minnesota was last week. The South Dakota fest is coming up. Different companies are holding their last season events for farmers to attend and learn about company doings as well as showing off their wares. In the 3-I states there is the farm progress show, followed by Husker Harvest days out in Nebraska.
The major happening that points to decent attendance at many of these is that the heat wave involving 90 and 100-degree heat seems to have moved east, leaving us to much more tolerable low to mid 80-degree temperatures.
USDA Yield Guestimates
A pertinent question is how much damage to yield has already been done by super dry conditions already. I have been in quite a few fields where the kernel count on most ears is 16 or 18 by 38 to 42. The kernels are still in the early blister stage. How many of these kernels will be retained vs aborted? If the plants receiver rain will maximum kernel depth be achieved or will they be shallow. I other fields I see decent grain fill and wonder where did the moisture come from the deliver this fill. Did the moisture come out of the air, or as dew as happens in the Napa Valley vineyards?
One question I have and am looking for verification is the effect of the some-times heavy smog coming for the Canadian wildfires. One noted meteorologist said that lots of benzene and formaldehyde were contained in it. Now to discuss the former compound, recognize that formula is CH2O, or very close to H2O. An increased level of CO2 generally gives a boost plant growth and productivity. It is not a poison as one group professes.
In the Fields: Corn
The rain delivered and delivered by one of the counter-clockwise rotating storms this weekend comes at a time when many areas in the Midwest have had almost no rain since late April. Many fields withy lighter on lighter ground, where compaction is a problem and sins created by planting when the ground was too wet yet and tomahawked roots are now noticeable, or some other factor such as rootworm feeding is present, were on their last legs and needed rain now. People’s prayers have been answered, and near-term moisture needs have been delivered.
This latest rain was important in that conditions for pollination were favorable, cooler temps with daily breezes to distribute the pollen. around. The next need was for additional moisture, moderate temps and sunshine to help fill the late blister to early milk ears. The kernel counts were good, but minimizing stress conditions help to minimize further kernel abortion.
With the drier conditions the common leaf diseases normally seen by now were scarce. Fungal spores drifting in from any distance or originating from local source need a moisture film to germinate and form an infection peg which has to penetrate the plants’ cuticle. Without heavy dews or rain the fungal infections were minimal. Most of the fungicide applications made were likely due to them being pre-booked at retail dealers in late December/early January rather that observed and diagnosed. That might be a good thing, but advised against in corn by plant pathologists who recognize that such use increases the risk of developing resistant strains of causal fungi. The time frame from early discovery to commercialization by the major firms is decades long. So preserving their high level of efficacy by limiting their use to actual needs should be important and taught.
There were two lengthy review papers published in 2017 and 2023 which discussed the generation and appearance of fungi strains which can attack plants, animals and humans. They are a long but good read and cover the strains and risk to each targeted victim. We will post them at our website. For example, there are more strains of fungi which attack humans and require medical treatment. Candida auris is one of these. It was in early years claiming a fatality rate among humans of 61%. The class of chemistry from which the medicines come from is the Azoles. So the question generated will be “Is a human medicine more important than a plant medicine?” We can often look to see what the effective life of a fungicide will be by watching what happen or happened to a product used in crops in S. America where there are more generations per seasons and greater selective pressure.
The Midwest’s major location of Tar Spot incidence is now central Iowa, in that it has been the area receiving the most rainfall, though that seems impossible. N Missouri may gain that distinction with the larger rainfall amounts they have received in recent weeks. What I would like to see happen is for more growers who have fields break with this ‘disease’ take tissue tests or conduct sap analysis to see which minerals are involved. To see a Mn level at 120 times normal calls for more investigation. In fact is may be valuable to have a site set up where growers who do such sampling can send in their blinded mineral test levels to see which minerals are excessively high or low. One thought among a few of us are wondering what plant disease leads to vascular plugging on a large scale.
In the Field: Soybeans
The situation for many growers was that they were foregoing planned trips and applications because the chance of getting a return was questionable. With the rain we are likely to see more Late R stage foliar fertilizer applications meant to minimize pod loss and increase seed size. Previously it was rare to see significant pod fill in any bean fields. It was looking like any of the aggressive management steps used by high yield bean growers were not going to pay off.
When checking out any bean field and rating the overall management I always first count the podded nodes on the main stem. Next, I count the number of branches and the podded nodes on those branches. The newer use of hormonal products which promote the formation of 4 or 5, 5 to 7, to 8, or 14 to 23 branches are possible and have been documented. I was in fields south of Mason City last week and found a main stem podded node count of 13 to 17, which is normal this season. When I included the 5 to 9 branches the podded node count jumped to 28 to 33. That leads to believing that planting soybeans abnormally early is not the only course to increasing yields. Recognize that increasing branch number increases the need for calcium, which be met by foliar Ca in a form that can penetrate the cuticle.
Nearly all the soybean contest yield winners use a strong foliar program to help the plants supply late nutrition to the late filling pods. Dry soils and high unmet nutrient demands by a high pod count necessitate late fertilization which can be restricted by vascular transport capacity. One’s view of this has to be that of a plumber. Application at those later R stages can generally be made by plane or drone. The exception can be by ground rig if a mix of P and sugar have been made at 14-day intervals to enable shorter internodes to form, thus a shorter plant height.
Observations in the last decade tell us that SB aphids and bean leaf beetles can be major yield robbers, especially with the former in 2003. Less rainfall must make for a concentrated sap which provides a richer diet to the aphids. So far, the only noticeable aphid populations have been spotted in the NW portion of the state, where they remain at low levels.
Drone Use
The use of drones in Ag has grown and will likely continue to do so as they fill a big niche. They won’t replace the high clearance Hagie, JD, Miller or N Holland sprayers but will fill in when the soils are too wet for ground rigs, when fields are near residential areas, when trees or rough terrain prevent plane application or when a person has many smaller or odd shaped fields. Near term I am seeing a number of young people who are trying to carve out their space in Ag while the need is there for such companies.
This year two brothers I work with went almost two months with no rain. When rain arrived, it was 4” in 15 minutes along with 100 mph winds which blew their corn flat. It had not tasseled yet, so it stood up but with 12 to 15” of goose necking preventing any ground application. Luckily a local, young drone operating neighbor offered to make the final applications needed.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.