Schmitz-Eiberger (2003) who studied the effect of low dosage UV-B
stress on apple fruit photosystems under laboratory conditions in
relation to fruit sunburn development. UV-B is known to damage
the reaction centres of photosystem II (PSII) (Iwanzik et al., 1983)
and also to negatively affect Calvin cycle enzymes (Krause et al.,
1999; Surabhi et al., 2009).