Planning for a drought should include management inputs that generally maximize your corn yield. You should plant early, when soils are fit; plant your normal seeding rate; fertilize for a good to excellent crop yield; plant your most productive fields to corn; utilize crop rotation on the remaining acres; hope for timely rains; and pray.
Dr. Joe Laur, Corn Agronomist at University of Wisconsin, gave this most comprehensive review of water use and potential crop losses for corn at the 2013 Wisconsin Management Conference. The data in Table 1 is from work by Rhoads and Bennett (1990) and Shaw (1988).
Table 1 Estimated Corn Evapotranspiration and Yield Loss per Stress Day_________________
Corn Growth Evapotranspiration Percent Yield Loss Per Stress Day
Stage____ (Inches/Day)___ Min. Avg. Max.
1 to 4 leaf 0.06 —-
4 to 8 leaf 0.10 —-
8 to 12 leaf 0.18 —-
12 to 16 leaf 0.21 2.1 3.0 3.7
16 leaf to VT 0.33 2.5 3.2 4.0
Silking (R1) 0.33 3.0 6.8 8.0
Blister (R2) 0.33 3.0 4.2 6.0
Milk (R3) 0.26 3.0 4.2 5.8
Dough (R4) 0.26 3.0 4.0 5.0
Dent (R5) 0.26 2.5 3.0 4.0
Maturity (R6) 0.23 0.0 _________________
Stress days for corn are when the corn plant fails to unroll its leaves overnight or quite early in the morning to begin rolling its leaves again.
