Fig. 6.

Carbon isotope discrimination, Δ¹³C, for sunlit apple leaves which expanded at start, middle and end of extension growth period in ‘Fuji’ and ‘Braeburn’ apple cultivars. All leaves were sampled in October for isotopic analysis. Δ¹³C of the two cultivars were statistically compared using the Mann–Whitney test. P-values are indicated where the differences are significant and NS where they are not. Values followed by different letters are significantly different.