Shattering represents the ability of grain to remain attached to the spike or inflorescence during the period of standing crop over-ripening and throughout the harvesting process. The manifestation of this trait is expressed in the spontaneous dropping of grains, which directly leads to a reduction in quantitative yield indicators for the farm.
The severity of shattering depends on the morpho-anatomical structure of the plant, in particular the strength of the attachment of glumes to the rachis, the degree of development of mechanical tissues, and the diameter of vascular bundles. Furthermore, the resistance of a variety is determined by the interaction of the genotype with the environment, as sudden temperature fluctuations and squally winds can trigger losses even in relatively resistant varieties.
Resistance assessment in variety trials is conducted on a five-point scale, where 5 points correspond to high resistance and 1 point to low. In addition to visual observations, methods of manual grain 'detachment', morphological analysis of spike structure, and instrumental measurement of grain retention force or counting of fallen seeds per unit area are employed.