Flowering responses of serradella (Ornithopus spp.) and subterranean clover (Trifolium subterraneum L.) to vernalisation and photoperiod and their role in maturity type determination and flowering date stability

Context Serradellas (Ornithopus spp.) are promising alternative annual legumes to subterranean clover (Trifolium subterraneum L.), for permanent, temperate pastures. However, many cultivars exhibit unstable flowering dates across years. This is a risk seed production and persistence.Aim study assessed how vernalisation photoperiod cues determine maturity type date stability among serradella cultivars.Methods First flower appearance was recorded early late maturing of yellow compressus French sativus Brot.) after exposure six treatments (0, 1, 3, 5, 7 or 9weeks at 5°C) with subsequent growth under four photoperiods (8, 12, 16 20h).Key results ‘Intrinsic earliness’ differed by only zero three nodes within species, indicating that determined primarily cultivar’s responses photoperiod. An interaction between these observed, precipitous decline in the requirement when exceeded 12h. Many also displayed persistent component their response, whereby long (20h) did not completely negate response vernalisation.Conclusions Later associated particularly need treatment minimise duration from sowing first appearance. Stable more likely cultivar has components its satisfied before autumn ends prevent premature flowering, spring overrides any unmet requirement.Implications Persistence requires selection suitable responsiveness