Irradiation as an alternative to methyl bromide for quarantine treatment of stone fruits

Irradiation can be used with cherries, apricots, or peaches as a quarantine treatment at 300gy's or less with little quality loss. Either irradiation or methyl bromide (MeBr) can be used as a quarantine treatment for 'Bing'' and 'Rainier' sweet cherries with acceptable results and similar fruit qual ity. Difference in stem condition and bruising were more evident for irradi ated 'Rainier' cherries than for MeBr treated 'Rainier' cherries, but these differences were small. Use of irradiation results in some firmness loss, for 'Bing' cherries when compared with MeBr, but irradiation treatment of c herries does not result in a loss of fruit and stem color, where the use of MeBr doses result in both fruit and stem color loss. Apricots ('Perfection ' and 'Rival') and peaches ('Regina') are tolerant to irradiation at 300 gy with little quality loss. Loss of firmness, color changes and increased in fernal breakdown are evident in both apricots and peaches at irradiation do se above 600 gy. If irradiation dose above 600 gy is required to meet quara ntine requirements unacceptable quality loss will occur in cherries, aprico ts and peaches.