How a Corn Plant Develops - Identifying Stages of Development

The staging system employed here divides plant development into vegetative (V) and reproductive (R) stages. Subdivisions of the V stages are designated numerically as V1, V2, V3, etc. through V(n), where (n) represents the last leaf stage before VT for the specific hybrid under consideration. The first and last V stages are designated as VE (emergence) and VT (tasseling). The (n) will fluctuate with hybrid and environmental differences. The six subdivisions of the reproductive stages are designated numerically with their common names in Table 1 below.

Each leaf stage is defined according to the uppermost leaf whose leaf collar is visible. The first part of the collar that is visible is the back which appears as a discolored line between the leaf blade and leaf sheath, figure 1 and figure 3. The characteristically oval-shaped first leaf is a reference point for counting upward to the top visible leaf collar.

Beginning at about V6, however. increasing stalk and nodal root growth combine to tear the small lowest leaves from the plant. Degeneration and eventual loss of the leaves results. To determine the leaf stage after lower leaf loss, split the lower stalk lengthwise figure 2 and inspect for internode elongation. The first node above the first elongated stalk internode generally is the fifth leaf node. This internode usually is about one centimeter (0.4 inch) in length. This fifth leaf node may be used as a replacement reference point for counting to the top leaf collar.

Figure 1
figure 1		 Figure 2
figure 2		 Fig 3
figure 3		 Fig 4
figure 4

Table 1. Vegetative and reproductive
stages of a corn plant.

Vegetative Stages

Reproductive Stages

VE emergence
V1 first leaf
V2 second leaf
V3 - third leaf
V6 - sixth leaf
V9 ninth leaf
V12 - twelfth leaf
V15 - fifteenth leaf
V18 - eighteenth leaf
VT - tasseling

R1 - silking
R2 - blister
R3 - milk
R4 - dough
R5 - dent
R6 - physiological maturity


 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*This system accurately identifies the stages of a corn plant. However, all plants in a given field will not be in the same stage at the same time. When staging a field of corn, each specific V or R stage is defined only when 50 percent or more of the plants in the field are in or beyond that stage.
 
 
 JHHill 9/25/2007