The germicidal and hormetic effects of UV-C light on reducing brown rot disease and yeast microflora of peaches.
Stevens, C., Khan V.A., Lu J.Y., Wilson C.L., Pusey P.L., Kabwe M.K., Igwegbe E.C.K., Chalutz E. and Droby S.
Crop protection, Volume 17, Number 1, February 1998 , pp. 75-84.
1998
บทคัดย่อ
The application of ultraviolet light-C doses (254 nm. UV-C) was used to determine the germicidal and hormetic effects on reducing brown rot of 'Elberta' peaches which were naturally and artificially inoculated with Monilinia fructicola. The results showed that a negative relationship existed between UV-C doses, colony forming units of the fungus, and the number of brown rot lesions. Also, the results of our study showed that the hormetic (beneficial) effect of low UV-C dose of 7.5 kJ m-2 induced host resistance by controlling latent brown rot infection. The hormetic effects of UV-C on peaches was photoreversed with visible light and resulted in the reduction of host resistance to brown rot. Furthermore, the results indicated that UV-C doses increased phenylalanine ammonia-lyase activity, delayed ripening and suppressed ethylene production. Additionally, the population of epiphytic yeast (Debaryomyces hansenii) increased curvilinearly on peach surfaces following UV-C irradiation up to 7.5 kJ m-2. Evaluation of the yeast population on the peach surfaces showed an antagonistic activity against M. fructicola. The possibility of the host peripheral defense by UV-C stimulation of the antagonist activity of a yeast is discussed.