Characterization data
Description of maize accessions is carried out according to the Descriptors for Maize, published in 1991 the by International Maize and Wheat Improvement Center (CIMMYT), Mexico City and International Board for Plant Genetic Resources (IBPGR; now Bioversity International), Rome. Description includes characterization and preliminary evaluation, as well as further characterization and evaluation.
CHARACTERIZATION AND PRELIMINARY EVALUATION (A)
4.1 VEGETATIVE
For descriptors 4.1.4 - 4.1.5 the mean of at least 20 representative plants should be used
4.1.1 Days to tasseling (male flowering)
Number of days from sowing to when 50% of the plants have shed pollen
4.1.2 Days to silking (female flowering)
Number of days from sowing to when silks have emerged on 50% of the plants
4.1.3 Days to ear leaf senescence
Number of days from sowing to when 50% of the plants have a dry ear leaf
4.1.4 Plant height (cm)
From ground level to the base of the tassel. After milk stage
4.1.5 Ear height (cm)
From ground level to the node bearing the uppermost ear. After milk stage
4.1.7 Number of leaves above the uppermost ear including ear leaf
Counted on at least 20 representative plants. After milk stage
4.1.8 Tillering index
Number of tillers per plant (average of more than 20 representative plants). At flowering
4.1.9 Stem colour
Indicate up to three stem colours in the order of frequency. Observed between the two topmost ears. At flowering
1 Green
2 Sun red
3 Red
4 Purple
5 Brown
4.1.10 Root lodging
Percentage of plants root-lodged. Two weeks before harvest
4.1.11 Stalk lodging
Percentage of plants stalk-lodged. Two weeks before harvest
4.1.12 Sheath pubescence
At flowering
3 Sparse
5 Intermediate
7 Dense
4.1.13 Tassel type
At milk stage
1 Primary
2 Primary-secondary
3 Primary-secondary-tertiary
4.2 EAR DATA
After harvest, using all ears (4.2.1 - 4.2.2) on at least 20 representative plants per accession
4.2.1 Husk cover
3 Poor
5 Intermediate
7 Good
4.2.2 Ear damage
Amount of ear damage caused by ear rot and/or insects, etc.
0 None
3 Little
7 Severe
4.2.3 Kernel row arrangement
Use the uppermost ear
1 Regular
2 Irregular
3 Straight
4 Spiral
4.2.4 Number of kernel rows
Count number of kernel rows in the central part of the uppermost ear
4.3 KERNEL DATA
After harvest
4.3.1 Kernel type
Indicate up to three kernel types in the order of frequency
1 Floury
2 Semi-floury (morocho), with an external layer of hard endosperm
3 Dent
4 Semi-dent, intermediate between dent and flint but closer to dent
5 Semi-flint, flint with a soft cap
6 Flint
7 Pop
8 Sweet
9 Opaque 2/QPM
10 Tunicate
11 Waxy
4.3.2 Kernel colour
Indicate up to three kernel colours in the order of frequency
1 White
2 Yellow
3 Purple
4 Variegated
5 Brown
6 Orange
7 Mottled
8 White cap
9 Red
4.3.3 1000 kernel weight (g)
Adjusted to 10% moisture content
FURTHER CHARACTERIZATION AND EVALUATION (B)
6.1 VEGETATIVE
Observe, when applicable, on at least 20 representative plants per accession
6.1.1 Total number of leaves per plant
After flowering
6.1.2 Leaf length (cm)
From ligule to apex. Measure the leaf which subtends the uppermost ear. After flowering
6.1.3 Leaf width (cm)
Mid-way along its length. Measured on the same leaf as 6.1.2
6.1.4 Venation index
Divide the number of veins mid-way along the ear leaf by the leaf width (6.1.3)
6.1.5 Leaf orientation
After flowering
1 Erect
2 Pendant
6.1.6 Presence of leaf ligule
After flowering
0 Absent
1 Present
6.1.8 Tassel length (cm)
After milk stage
6.1.9 Tassel peduncle length (cm)
After milk stage
6.1.10 Tassel branching space (cm)
Distance between the first and last primary branches. After milk stage
6.1.11 Number of primary branches on tassel
After milk stage
6.1.12 Number of secondary branches on tassel
After milk stage
6.1.13 Number of tertiary branches on tassel
After milk stage
6.2 EAR DATA
Observe, when applicable, on at least 20 representative plants per accession. After harvest
6.2.1 Prolificacy index
Divide the total number of ears by the total number of more than 20 plants
6.2.2 Ear length (cm)
6.2.3 Peduncle length (cm)
6.2.4 Ear diameter (cm)
Measured at the central part of the uppermost ear
6.2.5 Cob diameter (cm)
6.2.6 Rachis diameter (cm)
6.2.8 Number of kernels per row
6.2.9 Cob colour
1 White
2 Red
3 Brown
4 Purple
5 Variegated
6 Other (specify)
6.2.10 Shape of uppermost ear
1 Cylindrical
2 Cylindrical-conical
3 Conical
4 Round
6.3 KERNEL DATA
Observe, when applicable, on at least 20 representative plants per accession, after harvest
6.3.1 Kernel length (mm)
Average of 10 consecutive kernels from one row in the middle of the uppermost ear, measured with calliper
6.3.2 Kernel width (mm)
Measured on the same 10 kernels as 6.3.1
6.3.3 Kernel thickness (mm)
Measured on the same 10 kernels as 6.3.1
6.3.4 Shape of upper surface of kernel
1 Shrunken
2 Indented
3 Level
4 Rounded
5 Pointed
6 Strongly pointed