Prediction of Flowering Occurrence in Faba Bean (Vicia faba L.)

This study is about quantifying response flowering rate to temperature and photoperiod. Results indicated that the response of Faba bean flowering rate is described by beta-segmented ('Barekat, 'Saraziri', 'Eraghi') and beta-quadratic functions ('Gavi'). The use of quantitative data about the response of phonological development to temperature and photoperiod in faba bean is limited. This study was undertaken to examine phonological development of four faba bean cultivars ('Barekat; 'Saraziri', 'Eraghi', 'Gavi') under 11 sowing dates. The experiment was conducted in Gorgan during 2005-2006. Various response functions were evaluated for unctions, cardinal temperatures (base, optimum, and ceiling) for flowering and ceiling photoperiod (the photoperiod below which flowering rare begins to decrease), and photoperiod sensitivity coefficient (slope of the function in response to photoperiod) for flowering rate were determined. 'Barekat', 'Saraziri', and 'Eraghi' cultivars showed a qualitative long-day plant (LDP) response to photoperiod, and progress toward flowering stopped when photoperiod decreased about 10 Is per day. However, 'Gavi' cultivar showed a quantitative long-day plant (LDP) response to photoperiod. Ceiling photoperiod estimated by beta-segmented function for 'Barekat;'Saraziri', and 'Eraghi' cultivars were between 14.5 to 16.1 h and by beta-quadratic function for 'Gavi' cultivar was 15.3.