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University of Nebraska–Lincoln

UNL Water

Your natural resource for reliable water information.


Growth Stage Charts

Proper staging of your crop is important when estimating crop water use. For example, 4 leaf corn will use much less water than tasseling corn. Crop coefficients (Kc) for nine Nebraska crops based on stage of growth along with descriptions and pictures can be downloaded from this site to help you stage your crop.

The weekly ETgage change value multiplied by your crop stage's crop coefficient (Kc) will give you your crop's estimated water use.

If you are using the watermark sensors, knowing the soil type of the field is also important. Please see the soils chart (PDF, 10KB) which includes suggested irrigation trigger points. For more information on this topic, please see the UNL Extension publication "Watermark Granular Matrix Sensor to Measure Soil Matric Potential for Irrigation Management" (PDF).



Crop StageKc 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.10 2.20 2.30 2.40 2.50
V20.1 0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20 0.21 0.22 0.23 0.24 0.25
V40.18 0.18 0.20 0.22 0.23 0.25 0.27 0.29 0.31 0.32 0.34 0.36 0.38 0.40 0.41 0.43 0.45
V60.35 0.35 0.38 0.42 0.46 0.49 0.53 0.56 0.60 0.63 0.67 0.70 0.74 0.77 0.81 0.84 0.88
V80.51 0.51 0.56 0.61 0.66 0.71 0.77 0.82 0.87 0.92 0.97 1.02 1.07 1.12 1.17 1.22 1.28
V100.69 0.69 0.76 0.83 0.90 0.97 1.04 1.10 1.17 1.24 1.31 1.38 1.45 1.52 1.59 1.66 1.73
V120.88 0.88 0.97 1.06 1.14 1.23 1.32 1.41 1.50 1.58 1.67 1.76 1.85 1.94 2.02 2.11 2.20
V141.01 1.01 1.11 1.21 1.31 1.41 1.52 1.62 1.72 1.82 1.92 2.02 2.12 2.22 2.32 2.42 2.53
V16-Beginning Dent1.1 1.10 1.21 1.32 1.43 1.54 1.65 1.76 1.87 1.98 2.09 2.20 2.31 2.42 2.53 2.64 2.75
Silking1.1 1.10 1.21 1.32 1.43 1.54 1.65 1.76 1.87 1.98 2.09 2.20 2.31 2.42 2.53 2.64 2.75
Blister1.1 1.10 1.21 1.32 1.43 1.54 1.65 1.76 1.87 1.98 2.09 2.20 2.31 2.42 2.53 2.64 2.75
Dough1.1 1.10 1.21 1.32 1.43 1.54 1.65 1.76 1.87 1.98 2.09 2.20 2.31 2.42 2.53 2.64 2.75
Begin Dent.1.1 1.10 1.21 1.32 1.43 1.54 1.65 1.76 1.87 1.98 2.09 2.20 2.31 2.42 2.53 2.64 2.75
Full Dent.0.96 0.96 1.06 1.15 1.25 1.34 1.44 1.54 1.63 1.73 1.82 1.92 2.02 2.11 2.21 2.30 2.40
Black Layer0.6 0.60 0.66 0.72 0.78 0.84 0.90 0.96 1.02 1.08 1.14 1.20 1.26 1.32 1.38 1.44 1.50
Full Maturity0.1 0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20 0.21 0.22 0.23 0.24 0.25