I have to say, this is an article I had wished I would never have to write. EVERYONE is relieved when planting season is over. The decision to replant is one that we never want to have to contemplate. However, with severe storms, excessive rain, and a few frost scares over the past week, here we are. I want you to know that we need to make this decision less about emotions and more about what the probabilities and profit margins are. I built a spreadsheet that is going out to your FSA’s that will help with the decision. This article is about the process to make that decision.
First, we DO need to make some decisions, but DO NOT rush! Give the field some time to show its hand so to speak. Then make a decision and move on. If we look back and second-guess ourselves, at the end of the year we will regret the decision we made. This is why we make this decision based on numbers and probabilities and not our gut feeling. Once we make a decision don’t look back.
The second thing we need to do is get accurate stand counts. Take counts at multiple locations throughout the field to get a good vision on what we have. This existing stand count and your original plant populations will give us a percentage of our ability to hit our target yields based on past research and observations. Furthermore, we start to determine what our yield potential will be based on a projected replanting date and target population. We will then best calculate our replant costs. Once we figure all these components, we are ready to calculate the difference between the two yield potentials minus the replant cost. If that tally comes out to be near a wash then the decision to replant will likely not pay off. If the difference is great enough to cover all the costs then the decision to replant is viable. Spots in the fields adding up to five acres or less probably are not worth replanting.
Today our greatest risk to yield loss is stand reduction. This lowers our total yield potential by reducing the number of total ears per acre in a given field. With the semi flex hybrids we have today, our ability to out flex stand loss is fairly low. Not to mention that only works if the stand reduction is uniform, and what we have after a storm is anything but uniform. Those stretches of stand loss of 3-6 feet lead to a total potential yield loss of 10%. That’s in addition to the loss of the plants. There will also be a fight for weed control on these open spaces.
In regards to all this frost injury we have experienced in the later part of last week, again don’t rush to make a decision. Let us see how the crop responds to the frost itself. Reduction of stand is once again our greatest threat. Given all our crop has been through: cold soils, crust, heavy rains, and flooding, stand count reduction is very possible. The weaker plants that have been through the most are at the greatest risk of death from a frost. This isn’t because the frost killed it, but because the plant didn’t have enough left in the tank to survive. Therefore, give the plants 48 hours to collect themselves and start to grow again. Then give it another 72-96 hours to see what you have left. As far as corn goes, we could defoliate the entire plant until about stage V5 and not experience any significant yield loss. Soybeans on the other hand are a little more finicky. If they experienced a killing frost we will definitely know it sooner than with corn. Therefore, we are able to evaluate those stands and make a decision earlier.
A few last thoughts on replant before the phones begin to ring. Whatever you do, don’t try to mud the replant corn in! I had a fear of sidewall compaction the first time planting. I absolutely dread it in the replant situation. That added potential yield loss is part of what makes us regret the replant decision in the first place. Additionally, it is too early to start to think about selecting a shorter hybrid to replant. If at all possible, stay in the same maturity that you are currently in for at least the next week to 10 days. I don’t want us paying the short season penalty twice. After about May 26th our hybrids will naturally shorten up in maturity to catch up anyway, so when we move to a shorter season corn we do it twice before the first of June.
These are the cases that keep agronomists up at night. That is why I hope the tool that the FSA’s will have becomes useful to you in making the tough decisions. Whatever your decision, we here at UFC will do our level best to help you make lemonade out of lemons. When trying to make the best of a bad situation is when your trusted advisor is most valuable and the reason we are here. Now, with the help of your advisor, go make an educated decision and some lemonade.