Glossary
Seed and maize glossary
What the terms you meet on variety sheets and when choosing seed mean, and why they matter.
A
Alfalfa
Alfalfa (Medicago sativa) is a protein-rich perennial forage legume that can stay in the same field for several years and be cut more than once a year.
C
CRM (Comparative Relative Maturity)
CRM (Comparative Relative Maturity) is a relative value that expresses the maturity of a maize hybrid in day units by comparing it with known standard hybrids.
D
Dent kernel
A dent kernel is a maize kernel type with a distinct depression on its crown that makes it look like a horse’s tooth when dry.
Drought tolerance
Drought tolerance is a plant’s ability to maintain growth and yield under water shortage better than other varieties.
Dry matter (DM)
Dry matter is what remains of a feed or plant sample once all its water has been removed, usually expressed as a percentage.
Dry-down
Dry-down is the rate at which maize kernels lose moisture in the field after physiological maturity.
E
Ear tip fill
Ear tip fill describes how far kernels are set and filled from the base of the ear right up to its tip.
F
FAO maturity group
The FAO maturity group is a numerical scale that classifies maize varieties by the time they need to mature; the higher the number, the later the variety matures.
Feed barley
Feed barley is barley grown for its grain to be used as animal feed; it differs from malting barley in its end use and quality criteria.
Flint kernel
A flint kernel is a maize kernel type with a rounded crown whose outer part is made of hard, glossy, glass-like starch.
G
Germination and emergence vigour
Germination is the seed taking up water and putting out a root and shoot; emergence vigour is the germinated seed’s ability to reach the soil surface quickly and strongly.
Grain maize
Grain maize is maize grown for its mature kernels and threshed with a combine harvester once the kernels have dried sufficiently.
H
Hybrid seed
Hybrid seed is first-generation (F1) seed produced by the controlled crossing of two genetically different parent lines.
K
Kernel row number and kernels per row
Kernel row number is the count of kernel rows around the ear; kernels per row is the number of kernels in one row from the base to the tip.
L
Lodging resistance
Lodging resistance is a maize plant’s ability to stay upright rather than bend or fall over (lodge) because of wind, rain or a weak stalk.
M
Main-crop and second-crop sowing
Main-crop sowing is spring sowing of the field’s principal crop for the season; second-crop sowing takes place in the same year after another crop, usually a cereal, has been harvested.
O
Oilseed sunflower
Oilseed sunflower is the type of sunflower grown to extract oil from its seed; it differs from confectionery sunflower in its smaller, thin-hulled seeds with a high oil content.
P
Physiological maturity (black layer)
Physiological maturity is the growth stage at which maize kernels reach maximum dry matter accumulation and a black layer forms at the kernel base.
Plant density
Plant density is the number of plants growing per unit area, usually expressed as plants per decare or plants per hectare.
Plant spacing
Plant spacing shows how far apart seeds are sown within the row and how far apart the rows are; for maize it is given in centimetres as in-row and between-row distance.
S
Silage maize
Silage maize is maize grown so that the whole plant (stalk, leaves and ear) can be chopped, fermented in airtight conditions and stored as animal feed.
Starch content
Starch content is the percentage by weight of starch in grain or feed; in maize it is the main source of energy.
Stay-green
Stay-green is a plant’s ability to keep its leaves and stalk green and photosynthetically active for longer during grain fill and maturity.
T
Test weight (hectolitre weight)
Test weight, or hectolitre weight, is the weight in kilograms of grain filling a 100-litre volume (kg/hl) and indicates grain density.
Thousand kernel weight
Thousand kernel weight is the weight in grams of 1,000 kernels and indicates how large and well filled the kernels are.