Bob Nielsen held out hope for the corn crop, and still hasn't thrown in the towel. But the Purdue University Extension corn specialist acknowledges that unless relief comes across a broad area of the state soon, Indiana's yield potential will begin dropping fast.
A good portion of the crop is approaching or already at the tasseling stage. Some of the fields Nielsen has examined are tasseling, but the pollen is falling down inside the whorl. In other cases, pollen is ready to shed and there is no sign of shoots or silks anywhere in sight. This phenomenon isn't unusual when corn is subjected to severe drought, coupled with extremely high temperatures during the critical pollination period.
Nielsen's fear is that corn may miss the nick for pollination in many fields. This occurs when the plant sends out a tassel and sheds pollen, but the shoot and silks aren't out yet. Drought and heat mess up the timing, regardless of the hybrid involved. By the time the shoot and silks come out, the pollen may be gone.
The specialist goes so far as to say that unless there is relief soon, he won't be surprised to see areas of yields, if not whole fields, on certain soil types, or where pollination was severely affected, where the yield is simply zero.
Asked if low humidity in late June as some fields began to pollinate helped or hurt, Nielsen noted that it didn't help. But he added that even if there was more humidity, conditions were so dire that it likely didn't make much, if any, difference.Jim Camberato, Purdue Extension soil fertility specialist, answered in about the same way when asked if potassium deficiency showing up in some fields would impact yields, or if the drought was severe enough that it would overshadow it. He didn't hesitate. The drought will overshadow the nutrient deficiency. However, if you notice signs of deficiency, you still ought to soil test and see if the soil is truly low on potassium before you make plans for applying fertilizer for next year, he notes.