The Effect of Pre-harvest Sprouting in Cereal Seeds on Germination and Vigour at the Time of Harvesting and During Storage

Pre-harvest sprouting reduced the initial germination percentage and, as indices of vigour, the shoot and root dry mass of the six cereal species: winter wheat, spring barley, winter rye, winter triticale, oat and spring durum wheat. The reduction was species- and variety-specific and increased with increasing levels of pre-harvest sprouting. The reduction of the root dry mass was mainly due to the reduction of the root length and not of the number of seminal roots. Storage for nine months at 14 °C and 18 °C and at seed moisture contents of 14% and 16% (winter rye: 15%), respectively, resulted in a continuous loss of germination percentage as well as of root and shoot dry mass. Higher storage temperatures and higher moisture contents increased the rate of germination and vigour loss. The rate of germination loss during storage increased in the order: rye < triticale < wheat < barley and durum wheat < oat. The species-specific rate of germination loss was independent of the level of sprouting, whereas the species- and variety-specific rate of vigour loss increased with increasing sprouting level.