Genetic Variability for Early Growth Traits in Second Season Sunflower

Sowing a second season crop following the harvest of first (hereafter referred to as double cropping) is practice that allows for temporal diversification cropping systems increase efficiency land use and yield per unit area while improving ecosystem services. Sunflower particularly suitable cropping, especially under current context Southern Europe. However, planting sunflower in may result poor establishment very demanding terms seedbed preparations. In addition, most varieties available date belong late maturity groups (MGs), which were bred conventional cropping. Planting these further exacerbate risk failure. Here, we performed laboratory growth chamber phenotyping 11 hybrid oilseed with contrasting MGs assessed their field performance two consecutive years (2020 2021). We measured variables, such seed germination, seedling emergence dynamics final rates, post-emergence damage, characteristics are important uniform robust establishment. Under conditions, found statistically significant effect on cardinal temperatures water potential germination. maximum heterotrophic hypocotyl was higher (i.e., 85 mm) compared radicle 80 mm). The mortality rates soil aggregates ranged from 0 12%, depending size spatial distribution seedbed. germination 87 98% 99 100%, those 58 87% 78 94%, 2020 2021, respectively. average postemergence damage 13 44% 3 18% Bird main cause pre- losses. good possible southwestern conditions France, provided there no stress An optimal moisture ensures rapid limits pre-and due birds, by reducing duration phase, highly vulnerable bird damage.