By Matt Reese
For those who really like to watch corn grow, 2018 was a great year.
Ohio’s 2018 corn is by far the best-ever crop statewide and is also the highest average yield for many individual farms. In November, USDA’s National Agricultural Statistics Service bumped Ohio’s corn yield up 16 bushels from last year’s report to an average yield of 193 bushels per acre, which would be the highest on record if realized. Total production is expected to be 629 million bushels, up 14% from 2017.
The record crop got its start last May. April was just an extension of a very long, cold winter, but Ohio’s summer temperatures arrived right around May 1. What followed was an astonishing accumulation of heat units for the vast majority of the state. By Oct. 14 almost all Ohio locations being monitored were well above average on heat unit accumulation, according to NASS. Fredericktown had 1,048 GDDs more than normal and Akron Canton, Wright Patterson and Circleville were near 800 GDDs ahead or more. At the same time, moisture levels from persistent late-season rains kept the corn productive. Though there were pockets of dry weather mid-summer, nearly all of Ohio got more rain than normal through the 2018 growing season. Some Ohio locations, including Circleville, Waverly and Newark had around a foot more precipitation than normal from April through Oct. 14, according to NASS.
Peter Thomison, the Ohio State University Extension corn specialist, knew corn yields would be good this fall, but he was still surprised at the production of Ohio’s corn crop.
“As the season progressed and they kept forecasting higher yields, I was not prepared for the magnitude of these yields. Where did the yields come from? They were so much higher than even last year’s record,” Thomison said. “We had very good yields in the Ohio Corn Performance Test (OCPT) that paralleled what we were seeing around the state.
“We had one location in Upper Sandusky we lost because it got wet early. The location that did the best was Greenville. In past years, it has been one of our lower yielding locations because it simply had not been getting enough rain. We had hybrids going over 300 bushels there this year and at other locations. We had average yields over the early and the late tests ranging from 279 to 290 in Greenville. The next best location was Bucyrus that had averages from 270 to 280. South Charleston averaged in both tests around 270 and Washington Courthouse was at 270. These are phenomenal yields when the average yields are like that. Van Wert had lower yields around 250 and the lowest was in the northeast in Mahoning County and it was averaging around 205 bushels over the early and late tests. It still did very well considering it was planted on May 26. Those northern locations were both planted later.”
The path to the fantastic corn yields in 2018 started in early May.
“This year there was virtually no corn planted in April but then much of the state started planting around May 1 and then it just took off. It was very uniform. Some years it seems like Ohio has three corn crops, some that gets in during April, some that is planted in early May and then there is a delay and we see more planted in late May. This year we really didn’t see that for the most part except for a relatively small percentage of the total acres in the very northern part of the state,” Thomison said. “It was a good planting season and that led to uniform emergence, rapid crop development and growth because of the warm temperatures in May. Sometimes we get the crop planted and it just sits in the field and looks bad for two weeks while we wait for warm weather. We didn’t really have that issue this year. We talk about uneven emergence in fields and how that can translate into lower yields because there is a certain percentage of plants not competing effectively. That was not as much of an issue this year as I have seen in past years because the seedbed conditions were so favorable that there was much greater uniformity of emergence.
“Then we got phenomenal GDD accumulation. We had one year in South Charleston many years ago where we accumulated 2,500 heat units and the crops did very well that year. This year from planting to harvest at Greenville — from May 9 to Oct. 23 — we had over 3,500 heat units. Those are amazing heat unit accumulations. We also got rain at the same time we were getting those higher temperatures and that more than compensated for the warmer temperatures for the corn.”
The fast progress of the 2018 corn crop also led to an early maturing and dry crop, which, along with strong yields, helped offset low market prices.
“The corn is dry this year,” he said. “We can trace that all the way back to May 1 when this crop got planted and then we had this huge accumulation of heat units through the growing season accelerating crop development and resulting in faster dry down.”
There were clearly many factors lining up for the success of Ohio’s 2018 corn, but there were plenty of challenges too. While much of the state enjoyed some of the best planting conditions in many years, extreme northern and northeastern Ohio experienced very wet conditions through May and June. Some of those areas struggled all season after the delayed start, including an extended stretch of dry weather in mid-summer.
Nearly all of the state saw at least some disease pressure due to warm, wet conditions and some fields saw yield-limiting disease issues.
“Rich Minyo, the manager of the OCPT, commented that he had seen a lot of leaf disease in test plots this year and that our highest yielding locations were associated with fungicide applications at tassel this year,” Thomison said.
In some cases, heavy disease pressure was evident even in fields that had been sprayed.
“Gray leaf spot has not gone away. This year it certainly impacted yields over a wide area. There was a dry spell in July that slowed it down but then it came on late with the warm wet weather. It looked like, in some locations, the fungicide application didn’t keep the disease in check for some hybrids. It delayed it, but there was still enough disease pressure that it impacted yield.” Thomison said. “I was pleasantly surprised that stalk lodging didn’t cause major problems this year. We certainly had stalk lodging but it wasn’t of the magnitude that you might expect with the weather and conditions we saw this fall. It wasn’t a massive, widespread problem. It was manageable.”
The late, wet conditions also set the stage for some ear mold problems.
“We saw ear molds at most of our OCPT sites. It did not appear as severe as what we saw a couple of years ago. Grain from the majority of the hybrids looked pretty good, but there were a couple that certainly fell victim to ear rots,” he said. “We saw Gibberella, Diplodia and Trichoderma. We are starting to see Trichoderma ear rot more often. In the past, it’s been regarded as uncommon. Trichoderma ear rot is not associated with mycotoxins but it can certainly reduce kernel quality.”
The abundant rainfall through the season also led to some nitrogen loss.
“Nitrogen loss was certainly a yield limiting factor in some fields but it was not as much of an issue as I thought it would be given the amount of N that was applied and the amount of rainfall we experienced,” Thomison said.
The challenges have continued through harvest that has been slowed down by the big yields, occasional standability issues, full elevators, logistics, and wet, cold weather. Still, by the week ending Nov. 11, 78% of Ohio’s corn crop was harvested, which was ahead of the 69% last year, but just behind the five-year average of 81%, according to NASS.
“We will see no benefit from delaying harvest at this point. It is not going to dry down any more. It will just go from bad to worse out there,” Thomison said. “There are some elevators not taking any more corn. In some years, growers look at leaving corn in the fields as alternative storage. This is not going to be the year for that.”
Even with the challenges, 2018 will not soon be forgotten because of its incredible corn yields.
“We don’t see years too often when there is no appreciable planting in April. Then everything changed in May and from then on we got the right rainfall, the right temperatures, the right sunlight, at the right time in the corn plant’s life, and we didn’t have major limiting factors from the weather. That maybe applied more in the southern two-thirds of the state than the northern part of the state, but that was certainly in large part responsible for the yields we saw this year,” Thomison said. “Part of these yields are due to the fact that growers have become more savvy about the inputs they are using, including establishment practices, seeding rates, and fertilization. You can’t downplay the importance of a good agronomic manager. It is more of an art form than a science.
“I also have to put a plug in for genetics. We can’t overlook the resilience of the hybrid genetics. We saw some sites that were very dry this year in Wooster and Beloit from mid-July through late August and we still ended up with average yields close to 250 bushels. That just tells you that we’ve got awfully good genetics out there that sometimes get overlooked. Traits can help in some situations, but I am talking about base genetics. The improvements we are seeing are really remarkable.”