Efficiency of salicylic acid spraying on improving the characteristics of Pearl Tangelo mandarin in cold and common storages

Citrus is one of the most important fruit crops known by human. They are mainly grown in humid and arid subtropical regions. Citrus fruit undergo physico-chemical changes such as shrinkage, weight loss, decay as well as decrease in vitamin C during storage, which directly affects on fruits quality. Pre-harvest foliar application of salicylic acid (SA) is an efficient and safe technique to maintain fruit quality during storage. This study was carried out to evaluate the pre-harvest spray of SA (0, 1, 3 and 5 mM) on improving the shelf life and fruit quality of mandarin (Citrus reticulata L. ‘Pearl Tangelo’). The fruits were stored for one month at common storage (12±2˚C) and refrigerator (4±1˚C) and factors included peel moisture (%), fruit peel, juice and pulp weight (%), pH, TSS, TA, TSS/TA and vitamin C evaluated every week. The results showed that salicylic acid played a major role in increasing of fruit storage life. The highest percentage of peel moisture in both temperature conditions was observed with 5 mM salicylic acid. Low concentration of SA significantly preserved vitamin C, as the highest amount of vitamin C (64 mg per 100 ml of juice) were belonged to 1 mM salicylic acid at both common and cold storages. The lowest TSS/TA (9.2) was obtained with untreated SA-fruits in the common storage. The peel moisture (%), vitamin C and TSS/TA decreased during storage. The pH of fruit juice increased slightly in the second to fourth week of storage compared to the first week. There is a negative correlation between fruit juice weight (%) with TSS and TSS/TA. Since salicylic acid treatments are easy to set up and inexpensive, pre-harvest foliar application of SA could be a useful strategy to maintain physico-chemical and sensory quality parameters of mandarin fruit and prolong the storability of fruits during storage.