Fig. 3. a and b. Genotypic coefficients of photoperiod sensitivity for the 16 H. vulgare subsp. spontaneum accessions and four H. vulgare subsp. vulgare cultivars described in Table 1. The group designations correspond to those in Fig. 2. Panel a shows the genotypic coefficients of photoperiod sensitivity for days to first node appearance (Dev31) and panel b shows the genotypic coefficients of photoperiod sensitivity for heading date (Dev49). Group means followed by the same letter are not significantly different at the 0.05 probability level.