Radio frequency treatment in naturally infected peach reduced brown rot incidence to less than 26% and complete brown rot control was achieved in nectarines

Brown rot caused by Monilinia spp. is the most important postharvest disease of stone fruit. In previous work, radio frequency (RF) treatment for 4.5 min applied with fruit immersed in water at 40 ?C was very promising for the control brown rot on peaches and nectarines. In the present study, the efficacy of this radio frequency treatment was studied employing different infection times, inoculum concentrations, fruit maturity levels and in naturally infected fruit. Generally, infection time and maturity level of fruit did not have a significant effect on the RF treatment efficacy and brown rot incidence was significantly reduced in fruit inoculated 0, 24 or 48 h before treatment and at all maturity levels evaluated in both peaches and nectarines. RF treatment significantly reduced brown rot incidence at all inoculum concentrations evaluated (103, 104, 105 and 106 conidia mL?1). However, in peaches, the treatment efficacy was slightly less when the inoculum concentration was increased to 105 or 106 conidia mL?1. In naturally infected fruit, brown rot incidence was significantly reduced from 92% among control fruit to less than 26% in peaches and complete brown rot control was achieved in nectarines. RF treatment did not have an effect on fruit firmness in the varieties tested, and even a delay of fruit softening was observed. Moreover, both external and internal fruit appearance was not affected by the treatment. The figure shows brown rot incidence in ?Roig d?Albesa? peaches (A) and ?PP-100? nectarines (B) artificially inoculated with Monilinia fructicola 0, 24 and 48 h prior to radio frequency treatment for 4.5 min with fruit immersed in water at 40 ?C (?) or untreated (?). After treatment, fruit were incubated for 5 days at 20 ?C and 85% RH. Arcsine-transformation of the data was performed before statistical analysis. Non-transformed means are shown. Means with the same uppercase letter for each infection time or with the same lowercase letter for each treatment are not significantly different (P < 0.05) according to LSD test. ? Original title and source Effect of host and Monilinia spp. variables on the efficacy of radio frequency treatment on peaches ?M. Sisquella(a), I. Vi?asa, ?P. Picouet(b), ?R. Torres(c), ?J. Usall (c), josep.usall@irta.cat ?a Food Technology Department, University of Lleida, XaRTA-Postharvest, Agrotecnio Center, 191, Rovira Roure Av., 25198 Lleida, Catalonia, Spain b IRTA, Food Processing and Engineering, Finca Camps i Armet, 17121 Monells, Girona, Catalonia, Spain c IRTA, XaRTA-Postharvest, 191, Rovira Roure Av., 25198 Lleida, Catalonia, Spain Postharvest Biology and Technology, Volume 87, January 2014, Pages 6?12 ? KeywordsMonilinia fructicola,? nectarines, heat treatment, brown rot, Poscosecha?????????? postcosecha????? postharvest?????? na-oes? ?? ??? ?????? ?????? post-r?colte????? ???? ?? ???????????????????????????????? na-oogst???????????? post-raccolta???? Obr?bka po?????? p?s-colheita??????????????? ???????????????????????? hasat sonras????????????????????? Ernte???? ????????????????????????? ???? ?????????????????? postcollita??????????????? poskliz?ov頠???? ?????? ?? ??????????????????????????????? nakon branja???? pozberov頠?????????????????????? obdelovanje zemlje po??????????????? post-colleita????? ????? ?????????? pascapanen?????? ?il?onn postharvest??????? ????????????? p?c ra?as???????????? derliaus apdirbimas po?? lepas tuai??????????? ?? ?? ??????? post-recoltare? ?????? ?????? ???????????????????????? ?????????????????????????? ??????????????????????????? sau thu ho?ch?? ?????????????????????????????? zangemva kwenkathi yokuvuna Melocot?n???????? durazno?????????????? peach?? perske? ?????????? ?????? p?che?? ??????????????????? ??????????? perzik?? pesca??? brzoskwinia??????????????? p?ssego????????????? ?????? ?eftali?? ??????????????????????????????????????????? ????????????????????????????????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????????????????????? Nectarina??????????? pel?n nectarine??????????? nektarien??????????? ??????? ?????????????????????? ???????????????????????? ?? ????? ?????? ?? ?????????????????????????????? nettarina???????????? nektarynka??????????????????????? ?????????????????? ?????????????? ??????????????? ?????????????????????????????????????????????????????????????????????????????????????????????????????????????