Analysis of the temporal dynamic of changes in cum. Fv/Fm at
0.3 revealed no statistically significant differences between the different
groups before dai 12 (Fig. 9). Before dai 10, cum. Fv/Fm at 0.3
is always close to 0. On dai 10, means of cum. Fv/Fm at 0.3 in leaf
discs of susceptible butterhead and batavia lettuce cultivars/lines
increased; at this date, however, differences between leaf discs of
the different groups were not significant.