The 2018 planting season is coming up very quickly for most of us and has already started for our fellow growers in the Delta. As this planting season approaches, I look at current conditions and the 30-day forecast, things don’t look ideal. A majority of the corn belt has snow on the ground and if you don’t have snow, soil temperatures are still in the 30’s. The 30-day forecast for central Iowa, doesn’t give us temps above 60° until mid-to-late April. When you add the probability that we are going to get cold spring rains into that picture, it looks like our soil is going to take some time to warm up.
I know there are a lot of growers that like to get started as soon as they can, or once the soil is mostly fit to plant. I also understand that universities have research where they remind everyone that the earlier you plant corn, the higher probability of yield. What those papers/reports never talk about is the planting conditions. Cold temps delay emergence, give pathogens more time to get past the defense of our seed treatments, and ultimately end up reducing the stand and hurting yields. Now you throw soil conditions that are a bit wet to plant, but the universities calendar says go, so we go; smear sidewalls along with adding some compaction here and there. In this situation, our haste has reduced our stand and limited our yield across the field, or acres we planted, just to hit a calendar date.
There are extremes in the other direction as well. There are a few people that say, since corn doesn’t germinate until the soil gets to or above 50°, you shouldn’t plant until the soil gets to 50°. That’s fine if you only have a few acres to get over, and if that was the case I might even cherry pick a day here and there. The reality is that we have more acres to plant and what seems like less time to plant them. I still hold steady with my belief that we have more time than we think and we need to make sure we do our best job of planting each field we have.
Let’s look at some of the options growers have to combat everything that is thrown at them in a planting season.
First off, a good seed treatment. I know with the financial difficulty in the current agriculture economy, a lot of growers were looking for areas to trim costs, but a good multi-active ingredient fungicide and insecticide seed treatment is not something to cut back on. A good seed treatment, in my opinion, allows growers to get started planting before the soil temp is at or above 50°. I tell growers that if you have a good seed treatment and the 5-to-10-day forecast is for rising temps, go ahead and start at 45°.
Second, proper planting depth can reduce the effects of possible environmental changes (temperate drop, cold rain, etc.). If corn is planted between 2 - 2 1/2” there is more soil between the seed and surface to reduce temperature fluctuation. At this planting depth, the soil can actually warm up rain water by the time it gets to the seed, if the soil temperature is higher than the temperature of the rain.
Next, if the grower has starter on the planter, they can add additional fungicides in-furrow. There have been many studies done that show by adding a fungicide like Headline in-furrow, they can reduce some of the stress on the seed and seedling, which allows it to tolerate more or longer periods of unfavorable conditions. This gives the grower a wider window for planting.
Lastly, know when to stop planting when conditions are forecast to be unfavorable. If possible, planting needs to stop 24-36 hours before a cold or chilling rain. The seed usually takes in enough moisture for germination in the first 24-36 hours after it is placed in the ground. If the moisture is considerably colder than the seed, it can have adverse effects on the seed and plant that will/may come from it. It can corkscrew underground, it can cause it to leaf out underground which prevents it from emerging, or the seed will not even germinate. All of these effects have a negative relationship to yield.
When you look at all the options growers have to combat and eliminate these planting issues, a cold, wet spring doesn’t look as bad.