Postharvest UV-C irradiation on cut Freesia hybrida L. inflorescences suppresses petal specking caused by Botrytis cinerea
Anastasios I. Darras, Daryl C. Joyce and Leon A. Terry
Postharvest Biology and Technology, Volume 55, Issue 3, March 2010, Pages 186-188
2010
บทคัดย่อ
Postharvest petal specking caused by Botrytis cinerea is a major concern for freesia growers and sellers in Holland and the UK. Germicidal and inducible host defence effects of UV-C irradiation were evaluated. UV-C irradiation of freesia inflorescences after artificial inoculation with B. cinerea (i.e. the germicidal effect) was more effective in reducing petal specking, compared to UV-C treatment before artificial inoculation (i.e. the defence induction effect). Cut freesia inflorescences exposed to 1 kJ m−2UV-C after artificial inoculation with 104 B. cinerea conidia mL−1displayed reduced disease severity scores, lesion numbers and lesion diameters by 74, 68 and 14%, respectively, compared to non-irradiated control inflorescences. In contrast, UV-C irradiation with 1 kJ m−2before artificial inoculation reduced lesion numbers and lesion diameters by 13 and 24%, compared to the non-irradiated controls. Higher UV-C doses of 2.5 or 5 kJ m−2reduced disease severity scores, lesion numbers and lesion diameters when applied after artificial inoculation, but enhanced disease when applied before artificial inoculation. Vase life of cut freesia inflorescences irradiated with 0.5, 1 or 2.5 kJ m−2UV-C was maintained equal to non-irradiated controls. However, 5 kJ m−2resulted in phytotoxicity evident as petal discoloration and reduced vase life compared to non-irradiated inflorescences.