No. 17 Article 5/July 20, 2007

Corn During Grainfill

Rainfall this week has eased concerns about lack of water reducing corn kernel number, and this year should be one with relatively high kernel counts per acre. That means that yields will depend mostly on how well kernels fill before the crop reaches maturity.

Here are things to watch as the crop goes through the process of producing sugars in the leaves and moving the sugars through the stalk to the ear and into kernels, where conversion to protein, oil, and (mostly) starch takes place:

While most signs remain positive for the Illinois corn crop in 2007, a return to unfavorable (hot, dry) weather, or disease (even foliar fungicides do not protect directly against diseases that invade through the roots) could result in rapid deterioration of the canopy and a rapid end to grainfill. The earliest-pollinated crop is now starting into the milk (R3) stage, and kernels will fill rapidly from now on. The race is on to see whether the plants can remain healthy long enough to maximize the considerable yield potential in fields now.--Emerson Nafziger

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