SALUS gPhase Documentation
Lydia, Brian, & Bernardo
August 9, 2018
Definitions of gPhase
- Until emergence
- Until induction (WH,BA incl. vern. Others incl. juv.)
- Until end of veg. growth (last leaf stops expanding)
- Until ear stops growing
- 4Until maturity
- 5Matured
Relation of gPhase to Corn Stages
- gPhase 1: begins when corn emerges (VE)
- gPhase 2: begins ? and ends when the leaves stop growing (V10?)
- gPhase 3: begins when the leaves stop growing (V10?) and ends when vegetative growth stops, tassel is the last vegetative stage (VT)
- gPhase 4: grain fill period, begins at R1 and ends at physiological maturity (R6). Beginning of phase 4 should correspond to “silking” (“anthesis”)
- gPhase 5: begins at physiological maturity (R6)
Corn Stage Information
Vegetative Stages |
|
Emergence |
|
First Leaf |
|
Second Leaf |
|
… |
|
Sixth Leaf |
|
Tenth Leaf |
|
… |
|
V(n) |
nth Leaf |
Tassle |
Reproductive Stages |
|
Silking |
|
Blister |
|
Milk |
|
Dough |
|
R5 |
Dent |
Black Layer (Physiological Maturity) |
Timing information:
- The tassel is visible about 2-3 days prior to silk emergence
- Blister stage (R2) occurs about 10-12 days after silking (R1)
- Kernel Milk stage (R3) occurs about 18-20 days after silking (R1)
- Kernel Dough stage (R4) occurs about 24-26 days after silking (R1)
- Kernel Dent stage (R5) occurs about 31-33 days after silking (R1)
- Physiological Maturity (R6) occurs about 55-65 days after silking (R1)
Sources:
http://www.agronomy.k-state.edu/extension/crop-production/corn/corn-growth-and-development.html
https://www.agry.purdue.edu/ext/corn/news/timeless/grainfill.html



Figure 3. Daily time series of gPhase and LAI. LAI stops increasing at the start of gPhase 3.