Hopefully you're getting all the water you need in terms of rain or irrigation and you will have healthy plants with well-filled ears. That will be the case for some of you. However, many of you, especially in the central Corn Belt, are likely to run into some symptoms and situations not seen since the drought of '88. For Illinois, there was a drought just a few years back, but not to the severity of this year's event so far.
Here are some things to watch for.
Barren stalks- Even where fields look fairly normal in height and have ears that emerged when they should have, the excessive heat took its toll. Dave Nanda, plant breeder and director of genetics and technology for Seed Consultants, Inc., says that he has noticed four or more barren plants in 1/1000th acre. That's 4 ears you won't get. Each ear per 1/1000th acre is generally worth around 7 bushels per acre in a normal year.
Variation by soil type- If you have two distinct soil types in one field, especially if the soil type affects water-holding capacity, you may have two distinctly different fields of corn in the same field. Lower ground and wetter soils, the kind that often flood most years, may have the best corn this year. Best could be relative unless widespread rain returns soon. Tongues of soil that has less water holding capacity will stand out because the plants will be much smaller and have stressed out early.
Poor ear tip fill- This is a problem anytime it is hot and dry during grain fill. It could be a bigger problem this year if some of the ear tip, the last to pollinate, didn't pollinate in the first place. Much of the loss of kernels at the tip is usually due to ear tip abortion. This time it may be due to lack of fertilization and ear tip kernel abortion both.
Nutrient-deficient plants- The nutrients may be there, but the plants can't get them because roots can't take them up because it's so dry. In the case of potassium, the deficiency could be real. You'll want to check that with a soil test. In the case of nitrogen, even if there was plenty of N applied, deficiency symptoms may appear as the plants can't get to the N in usable form.
Spotty kernels on ears- Each plant will try to make some kernels if possible. If pollination was affected, especially if silks were delayed, you may only find a few scattered kernels poor ear. That's because times were extremely tough at pollination.Weak stalks- As the season progresses expect for stalk strength to be compromised. Plants will cannibalize nutrients from other plant parts to try to produce some kernels. One place where it will get the nutrient is from the stalks. Whatever corn is out there may be designated for early harvest while stalks are still standing.