Photo by Joan Leffel.

We need to reflect back on what we learned this year

By Harold Watters, Ohio State University Extension

I think we screwed up the 2020 cropping season in 2018 and 2019. I hope the yield estimates we saw in OCJ in August hold up. Matt always goes back and checks with the growers at harvest, this year with the virtual tour I hope we can still check those actual yields against the estimates. At any rate the screw ups we did in 2018 and 2019 were a bit out of our control… meaning we were too wet when we harvested in 2018 and too wet when we planted in 2019 — and that led to a lot of surface compaction, and probably some deeper compaction, too. To follow that up we had a mild winter in 2019-2020 so we saw limited freeze-thaw to take away some of those compaction issues. I do not suggest tillage this fall, generally, to solve the problem. We need to build aggregates and quit breaking up our soils into fine particles resulting in those surface crusts, and yes I will admit those intense rains also broke up our soil aggregates. All the more reason to have cover crops or crop residue to cover and protect out sensitive surface layer.

I’m not sure what we could have done better for the crop this year. We were able to take advantage of planting opportunities in northern Ohio early, but later dry weather somewhat overcame that advantage. Southern Ohio had almost the same delayed planting window that northern Ohio had in 2019. We know that crop production is about collecting sunshine — and putting that together with a crop to make sugars (C6H12O6) that the plant converts to starches, oils and protein. But when we do that with a June planting, we cut 30 days off the potential. And oh yes water — water in mid- to late-season can help overcome the delay but many of us didn’t have that either.

And then there were the pest problems that were maybe not as bad as they could have been.

My items of concern for 2020:

  • Frogeye leafspot. Yes, I saw it but it was at very low levels or absent for this year.
  • SDS — sudden death syndrome, again was here but we noticed it late. My guess is that it was lurking in the plant all season and probably impacting yield. Those of us with damp conditions at or shortly after planting probably had the causal fungus move into the plant then.
  • Gray leaf spot, and Northern corn leaf blight were both observed at low levels. Hybrid selection can reduce these diseases even further. The planes that flew around flowering, may not have been needed. We need to do a better job of scouting.
  • Insects — after the spring rush of armyworm things kind of slowed down. We did see red-headed flea beetle well into the season, however. Is this a new pest for us? And then my concern late-season is stinkbugs. Did you see them this year, I found several but not to the levels I have seen in the past. But still one we need to watch for late season just as we think we have the crop in the bank.
  • Weeds — for years we harped on marestail, now it’s Waterhemp. You must rotate herbicide programs to reduce the population of the seedbank, especially for waterhemp. Mark Loux’s mantra is “Go Rogue,” eliminate the plants before they go to seed — problem solved. But a significant pre-emergent program will reduce the problem too, and leave fewer weeds to pull. I next year pledge to apply two applications of a pre-emergent grass herbicide (e.g. metolachlor, acetochlor, etc.) one at plant and the second at post herbicide application timing. And I will also use a significant post herbicide that kills waterhemp, dead — and spray when the plants are small enough to be successful at that.
  • Nutrient applications — I am looking for free manure. The nutrients are the same and likely bring along some nitrogen with P, K, even sulfur for my crop. The next concern if there is no manure is potassium. In areas where we saw dry periods this year, I saw K deficiencies. We don’t want to run too close to our critical level on K, that’s 120 parts per million. With phosphorus (20 ppm) however, I can run a while in spots where I sit in the maintenance range or a little below.
  • And then there’s nitrogen, which was a big concern in 2019 and again in 2020. I think I covered needs early season, and just after sidedress application I had a couple of timely rains that put the N in the root zone. In my field research all the sites had a dry June, if I had 50 units or more of N next to the row then those plots didn’t show yellow during the dry spell, but where I planned to sidedress at V8 those treatments did. In past years the Corn Nitrogen Rate Calculator rate has been my best treatment; from appearances I think that will be the case again this year.

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