Abstract
Apricot fruit because of its high respiration rate and rapid ripening process has short storage period and should be offer to marketing immediately after harvest. This study was carried out to determine the optimum harvest time of apricot fruits to prolong their storage period and decrease its wastes. Split-split plot based on complete randomized block design were used for four traditional apricot cultivars include of "Germez shahroud", "Gorban maragheh", "Orduobad" and "Nasiri" (as main factor) in three harvesting stages (as sub-factor) based on fruit skin color. The first harvest was conducted when skin color had a predominantly green background with yellow tinges, the second and third harvest coincided with yellow background with green tinges and yellow-orange background color of fruits. Then fruits were packed in boxes with polyethylene covers and stored at 0-2 ˚ c and 85% RH. For 0, 7, 14, 21 and 28 days (as sub-sub-factor). After each storage period, fruits were tested for their quality attributes such as shriveling, gel breakdown and decay percentage. Other fruit properties included fruit weight, firmness, TSS, pH and EC were measured and data were analyzed. The cluster analysis results related to quality traits of fruits revealed four distinct classes. Results showed that optimum harvest time of all cultivars is when the fruit skin color has a predominantly yellow background with green tinges and prolong storage period. At these conditions, the fruits of "Germez shahroud", "Gorban maragheh", "Orduobad" and "Nasiri" could be cold-stored with suitable quality until 21, 28, 21 and 28 days, respectively.

Keywords: apricot, cold-storage, harvest time, packaging