Indeed, grain size has been postulated to be determined by the physical limitation of the size of the husk [12, 13], potentially due to effects of pre-anthesis temperature on floret growth .
The husk adheres to the underlying caryopsis through a cementing layer, which is thought to be composed of lipids [15,16,17,18].
Conversely, grains with reduced weights caused by high temperature stress [10, 11] might be expected to have reduced husk-caryopsis contact, resulting in poor quality adhesion.
Equally, the size of the husk organs would contribute to the capacity for contact between the husk and caryopsis.
The barley grain contains three internal lipid layers.
The thinnest is present in between the nucellar layer and the testa, whereas the thickest is present between the testa and the pericarp.
These tissues and the lipid layers develop as a unit.
The third lipid layer, the cementing layer, develops after the pericarp cuticle is formed.
Further, if a grain has skinned but retains a viable embryo, such grains will imbibe water more quickly and may over-modify with respect to intact grains, resulting in malting losses [1,2,3].
The quality of husk adhesion is influenced by both environmental and genetic factors, and the quality defect grain skinning has increased in severity in recent years with newer varieties being more susceptible to the condition .