Response of apple and winter pear fruit quality to irradiation as a quarantine treatment

Irradiation at doses between 0.30 and 0.90 kGy reduced apple firmness. Dose s of <0.30 key had no effect on apple firmness. Firmness lost due to irradi ation was cultivar dependent. Titratable acidity (TA) of 'Gala' apples was reduced at irradiation doses of 0.60 kGy and above. No loss of TA due to th e irradiation dose was evident, for 'Fuji' or 'Granny Smith' apples. Irradi ation did not influence the external color of apples, but change in the int ernal color of 'Gala' and 'Granny Smith' apples due to irradiation exposure was present. 'Bosc' pears lost firmness due to irradiation, and the firmne ss loss was dose dependent. Both, 'Anjou' and 'Bosc' ripened normally after irradiation exposure. There was an increase in scald for 'Anjou' that was dose dependent. Disease incidence of 'Fuji' and 'Granny Smith' apples cause d by P. expansum was reduced from about 80% of wounds with lesions to 30% a fter irradiation exposure. Irradiation had no effect on number of lesions c aused by either B, cinerea or M. piriformis. No effect was observed on deca y of 'Anjou' pear fruit naturally infected with P. expansum and B. cinerea However, a reduction in decay was observed in naturally infected 'Bosc' pea r fruits treated with 0.90 kGy.