Conditions have changed as of Monday 5/9 as that the temperatures are supposed to reach into the 90 F category for three or four days. That would be welcome in that it should warm the ground up and start us on the path of accumulating GDUs much faster than previous. Daytime highs of 47 F for most of the last week did nothing to add to the GDU totals. Missing the next rain plus getting warm and windy conditions would help all fields dry, especially after the weekend rains dropped from .5 to 3 inches of rain across the state. Where the rainfall amounts were the greatest and drainage is poor, missing the projected Thursday rain would allow for much fieldwork to get done.
Looking at the national tallies as corn and soybean planting totals for this date versus recent previous years, farmers and planting progress in the largest ten corn producing states, one can see that the ten largest corn states had less than 7% of the corn planted versus 41% of 2021 or nearly 40% vs the five- year average. The most redeeming statement regarding that huge deficit, is that ground temps remained below normal until May 9th. Thus, the largest cause of lack of planting progress was not wet soils but cold soils. Finally, we are now seeing that seasonal rains began to fall about two weeks ago. The large moisture front sitting over Idaho and Montana on Sunday project earlier to hit Iowa, moved northeastward and is now poised to move across N. Minnesota leaving us to dry out until Thurs and Friday.
The warmth that is arriving on Monday will begin to warm the soils, which until now were stalled in the low to Mid 40 F, will now start rising into the 50 F range where germination will happen quickly and the 115 GDUs accumulation will occur. Last week there were accurate stories being told of fields along Hwy 20 where the seeds swelled up and then rotted without sprouting. The seeds will imbibe moisture and swell up, but will then need heat to germinate the seeds and begin forming the sprouts which will push towards the soil surface. With sub 50 F temps the seedling starts to decay.
Very Early Planting in 2022
We will hear stories about farmers who planted corn during the time when the air temps remained low and soils were sub 50 F temps. In cases the crop scouts found that some of the earliest planted fields held <25k stands, low enough they will be inclined to do a total replant.
Many younger growers have begun to plant soybeans before they start with corn acres. They may finish a few nearby fields before switching to doing beans. This tactic may work, or it may backfire as areas and fields in northern and central Iowa experienced one or more nights of subfreezing temps. In the end it was the fields which had been planted into heavy stalk residue that captured the cold air allowing plants to suffer freeze injury. If the damage was below the cotyledons, the plants were unable to regrow new tissue and needed spot or full planting. It can be tough to make the tough an educated guess on the best course of action.
Planting Delays
Hindsight is perfect, while foresight remains an unknown. The replant guidance charts are not as much in stone as they once were. The summers seem to contain more GDUs with longer fall weather and later heat than we used to see. The common recommendation in the past has been to stick with the adapted hybrids for your respective areas until May 20th. Then if you have to change, do it incrementally by three to five-day jumps. With more corn fields dying prematurely from several different diseases related to micronutrient related deficiencies, it has been difficult to spot any corn fields that had been planted to a too full season hybrid. Instead, we are seeing greater rewards to the growers who spend the projected fungicide dollars on the nutrients which fund the plants nutritional needs until the normal seven days before the expected frost date. When that goal is met through good preseason and timely foliar mineral applications, a person can expect to see ears that are filled to the tip and very little dent to each kernel. Also consider there have been the introduction of several great 105 to 108 hybrids. That development means less yield drop-off if a grower needs to abandon a later maturity hybrid. Ten years ago, there seemed to be a large performance gap between 110/111-day hybrids and ones in the 102 to 105-day maturity group. Those gaps have been filled by many seed companies.
Back in 1991 the first planting opportunity for many growers in northcentral IA was May 21st, again a week later, and finally around June 5-7th. It became difficult to make the choice between getting a field planted and waiting until the ground was perfectly dry and fit. There was a lack of good adapted hybrids of less than 95 RM. Today the corn geneticists have developed much improved hybrids created for the many corn acres that have expanded into N Minnesota and the Dakotas.
All any of us can do is be ready to put in long hours with the larger planters most operators have, many with the higher speed options. If we are blessed with a seven-day break, most corn growers can get a high % of the corn crop planted. Realize that planting date may influence yield potential but not actual yield. The best advice I have heard is to watch conditions and not the calendar. Avoid causing compaction that can negatively affected the roots later in the season.
Microbials Again
Lots more growers are applying biologicals for the first time. Less than five years ago a well-known soil fertility researcher proclaimed that there was no such thing as a bug in a jug. More new microbial mixes containing specific and commensal species have invalidated that saying. The more pertinent question then may be: “Are you placing those living organisms into a favorable or a toxic environment?” Those microbes are tasked with releasing the organic acids needed to convert tied up or solid forms of minerals into the soluble and plant available forms that can move into the plant via the three processes.
Soybean Management
A well-publicized tactic of soybean growers seeking to produce higher yields has been to plant beans in the April 10th to 25th time frame in an attempt to form more podded nodes. With many of those growers having missed that window do they have to abandon their higher yield goals? “Definitely not”. Recognize that bean plants are much more influenced by hormones. There are commonly 9 important ones, at varying levels, and at varying times. Auxins make cells to grow long and plants to grow tall, sometime excessively so. Cytokines force plants to form more branches, have shorter internodes, and more roots with expanded reach. Plants utilize minerals and amino acids in forming hormones. If you can apply cytokines to the plant in artificial form, UV light breaks them down earlier than desired. If you apply minerals and AAs, as in Spraytec’s Impulse, the plants form the cytokines. And if you apply a cytokine producing bacteria and apply foliars containing cobalt to stimulate cytokine production by the bacteria thru a longer duration you get the extra branches to meet your planting early goal.1 plus 1 equal more than 2 in this case.
The next steps are to supply enough nutrition and energy to keep the plant from forming ethylene, the abscission producing hormone, followed by late nutrition thru the later R stages to build branch strength and maximize seed fill. If the board price on fall soybeans is $13 to $15/Bu, why not aim higher.
Might foliar sugar play an important role in raising high yield beans? Definitely. I know of only one certified PhD, University, plant physiologist who conducted a replicated study on this topic. His results were definitive with statistically significant benefits proven, but the results were never written up and publicized because they were not patentable. So what are your high yield plans and products? Check on our website for a few articles on proven high yields and products.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.