How does hot, dry, windy weather affect corn plants now?
When figuring your well’s capacity, a good conversion factor to remember is that 450 gallons per minute applies 1 acre-inch of water every hour. If your well pumps 900 gpm, you are applying 2 acre-inches every hour. This equates to 144 acre-inches every three days. For a 133-acre pivot, you can apply about 1.1 inches of water every three days. Calculate your application capacity and keep in mind how much stored soil moisture you have when scheduling your next irrigation.
Looking for that Million Dollar Rain
On dryland acres in Nebraska, we are already seeing crop damage in areas that missed out on the big rains last week. Corn in these areas is showing reduced growth, both in height and leaf area. The worst spots are already turning brown and dying. Even if we get significant rain soon, we already have yield loss accumulating. If we see rains in these areas by tasseling, we can still get good silk emergence and yields. If not, yields will deteriorate rapidly.
I have seen “head high” corn make over 150 bushels per acre if rainfall occurs before pollen shed. I have seen total losses where it doesn’t.
The “drought tolerant” hybrids may prove their worth, and all the breeding and improvement in silking vigor and pollen-silk interval apparent in most corn hybrids (compared to those available 20 years ago) will be invaluable this year. No-till and minimum tillage techniques save a couple of inches of water, and may make the difference between a crop and no crop in these areas. (See G2000 Tillage and Crop Residue Affect Irrigation Requirements.)
In most areas of Nebraska it has been several years since we’ve had this level of stress. Moisture conservation practices, residue, crop rotation, weed control, and good long-term soil management may really pay off this year.
Source: Thomas Hoegemeyer, Professor of Practice, Department of Agronomy and Horticulture with Chuck Burr, Extension Educator in Phelps County and Gary Zoubek, Extension Educator in York County