Unseasonably wet, cold spring weather has lingered longer than any Midwest farmer had hoped. These conditions create stress on seed germination and on seedlings. Plus, there were reports last week of frost damage to both corn and soybean seedlings in the areas I cover. Many farmers here in the north are assessing the damage and hoping to get replants done by June 10.

Whether farmers will replant corn or replant soybeans in earlier maturities will be determined after taking these three steps:

1. Evaluate the current stand.  

When evaluating the existing stand for population, only count plants that have a good chance of survival. Then, observe the uniformity across the field to decide whether replanting the entire field or portions of the field is justified. There are different stand count options to test for both corn and soybeans to perform an accurate count.

2. Compare yield potentials.

When judging the potential yield of the standing crop, again you should only count plants that have a good chance of survival. These tables for corn and soybeans help determine the percent of full-yield potential based on planting time.

3. Consider various management practices. 

Before replant occurs, remove any existing stand. Also keep in mind that most soil insecticides cannot be applied twice during the same growing season in the same location in the field.

The decision as to whether or not a farmer should replant really comes down to individual circumstances and “local conditions.” For example, I heard about a farmer from the Fargo area who had purchased a competitors’ soybeans without seed treatment. The wet, cold spring weather caused those seeds to literally rot in the ground. Note: Seed treatments like Latham’s trademark SoyShield and SoyShield Plus give superior control of most seed and soil-borne diseases, including damping off, as well as controls early season Phytophthora.

The germination in the particular farmer’s field mentioned above was so poor that it warrants a replant, but he’s in a precarious situation. Field conditions as of June 1 weren’t fit for planting, however, another 3 inches of rain is in the forecast this week with more precipitation likely in the 10-day forecast. If that farmer doesn’t get his crop replanted before the rain falls this week, it will most likely be another week or 10 days before he can get back in that field. Then we’re looking at a potential planting date of June 10.

If you’re considering a replant, it’s best to be in contact with your insurance agent. I’ve heard Federal Crop and others may not pay unless the field is inspected first. Plus, farmers also need to know the final planting date that will be covered by their policies.

The later the planting date, the better the chance we’ll have a killing frost before the crop matures. June 20-25 is a target date for switching soybean maturities in Iowa. However, our growing season is so much shorter in the north that June 4 is considered a late planting.

On our family farm near Enderlin in Southeast North Dakota, we usually plant soybean maturities ranging from 08 to Group 1. We’ve already switched to earlier varieties and are hoping the weather will allow us to get these planted before rain brings planting to a halt again. To inquire about soybean maturities in your zone, contact me or your local Latham® representative by calling 1.877.GO.LATHAM (1.877.465.2842).

Mid-May is here but there’s no need for farmers to rush into their fields to finish planting. Farmers across the Midwest are still within the time period for great yields, so there’s no need to switch crops or maturities now.

Due to the shorter growing seasons in northern Minnesota, as well as in North and South Dakotas, farmers try to get their crops in the ground as early as possible. May 6-13 are considered optimal soybean planting dates for much of Northeast South Dakota, while early May dates are recommended for the southern areas of the state. Optimal planting dates in North Dakota range from late April to mid-May.

Planting corn through May 15 is considered ideal in Iowa, but it sounds like almost all of the corn acres are planted across the state. For those farmers who still have some corn in the shed, there’s no need to even think about switching hybrids yet. Research shows that hybrids adjust to planting dates, so full-season corn hybrids can compensate somewhat for later plantings.

As planting is delayed, hybrids shorten the time between planting and silking. Full-season hybrids almost always outperform short season hybrids, so Iowa State University Extension Corn Specialist Dr. Roger Elmore has said farmers really don’t need to consider switching maturities until May 25.

Many planters are parked across much of Latham Country as measurable precipitation fell over the weekend, and rain clouds continue to hover this week. Moisture was needed to get many crops off to a good start, as well as to activate herbicides, in the north. It’s just too bad some of this precip came in the form of snow! It looks like fields will remain wet across much of the Upper Midwest this week, but sunshine and warmer temperatures are on the horizon.

As hard as it is, be patient and wait for soils to dry before planting resumes. Planting into unfit conditions can cause lower yields than delaying planting by a few more days. Working soils that are too wet now could lead to soil compaction and have negative impacts on your crops during the growing season including: stunted plant growth; slow infiltration of water and/or ponding; high surface runoff and soil erosion under normal or light rainfall; poor root system establishment; and nutrient deficiency.

The best rule of thumb is to let the field dry before doing fieldwork. Use a quick field test to check the soil moisture: mold a length of soil between your index finger and thumb, or roll it into a ball in your hand. Observe whether the soil breaks apart as you work it.  If you toss the ball of soil into the air and it shatters or cracks upon falling to the ground, then conditions are likely suitable for tillage or planting.

The arrival of spring weather is something every Midwest farmer anticipates. Early to mid-April brought favorable conditions for fieldwork. Many local farmers finished tilling soils while others started putting seed in the ground.

Soil temperatures across Iowa had been above the 50-degree mark, which is usually the target for corn planting to begin. However, a cold front moved in and soil temperatures have dropped a few degrees in recent days.

Even when soil temperatures are warm enough to plant, farmers must be certain that warmer air temperatures are in the forecast.  Warmer air temperatures are critical to protect the seedlings.  If the air temperature hits 20 degrees Fahrenheit or less after germination, the young seedling can be killed with the growing point of the plant right at emergence.

Remember, soil temperature for soybean planting is more critical than for corn. We recommend waiting until soil temperatures in a region reach – and maintain – 60 degrees Fahrenheit before soybeans are planted. Soybeans can germinate in a soil environment of about 55 degrees Fahrenheit, but if the air temperature after germination hits 28 degrees Fahrenheit or less, the young seedling can be killed with the growing point of the plant right at emergence. Adversely for corn, the growing point stays under the surface until much later.

One more consideration before you putting seed in the ground is to make sure soils are fit. Wet soils cause trouble from the beginning and all through the growing season. Compaction resulting from wet soil can kill root growth.

Latham Corn Product Specialists advise farmers to “take the crumble test” before reentering fields. Grab a clump of soil and watch how easily it crumbles. If it stays in a ball, conditions are NOT right for planting. If it crumbles easily, the soil is fit for planting.

We’re well within the optimal Iowa planting dates for corn, so take the time to let fields dry if needed. There are plenty of other uncontrollable factors that determine crop yield, so why not control the ones you can?