Effect of Preharvest Applications of Calcium, Anti- Ethylene Compounds and Their Combinations on “Canino” Apricot Fruit Quality and Storability

Abstract

This study was conducted during two sequential seasons of 2015 and 2016 in a private orchard located in El-Khattaba District, Menoufia Governorate, Egypt to investigate the influence of calcium chloride (CaCl 2) at 2%, anti-ethylene compounds namely Aminoethoxyvinylglycine (AVG) at 150 ppm and 1-Methylcyclopropene (1-MCP) at 25 ppm in addition to their combinations (CaCl 2 plus AVG, CaCl 2 plus 1-MCP, AVG plus 1-MCP and finally CaCl 2 plus AVG and 1-MCP, at the same concentrations) on fruit drop at harvest and yield as well as firmness, jelly pulp and other quality parameters of "Canino" apricot fruits during cold storage at 0 o C and 90-95% RH for one month. During 2015 and 2016 seasons, apricot trees were sprayed three times starting after full bloom, fruit setting and finally ten days before harvest. Quality of sprayed fruits was evaluated at harvest and every ten days of cold storage. The results showed that external browning, internal browning, jelly pulp, fresh weight loss, total sugars, total soluble solids (TSS), TSS to acidity ratio, carotene content were increased, while firmness, electrolyte leakage, vitamin C, acidity, chlorophylls a and b contents were decreased with the progress of cold storage duration. Furthermore, the results revealed that all used treatments reduced external and internal browning symptoms in addition to jelly pulp formation and fruit fresh weight loss. Moreover, the treatments lessened electrolyte leakage of fruits, retarded the loss of fruit firmness and were effective on keeping the physical and chemical qualities relative to the control treatment. Finally, this study indicated that the addition of CaCl 2 to anti-ethylene compounds was more effective than the individual application of each compound on reducing fruit abscission, increasing average fruit weight and yield/tree at harvest plus retarding the loss of firmness, other physical and chemical qualities and prolonging the storability of "Canino" apricots stored at 0 o C, especially the combination of AVG and 1-MCP in the presence of CaCl 2.

Pre-Harvest Treatments On Canino Apricot Trees to Improve Yield, Fruit Quality at Harvest and During Storage

“…In this respect, Taha and Sherif (2015) revealed that, spraying four times with different sources of calcium such as Inca, Calbor and CaCl2 at two concentrations (1 and 2 %) on Canino apricot trees led to increase yield and improve physical and chemical fruit quality. Also, Nagy (2018) concluded that spraying CaCl2 at 2% alone or combined with Aminoethoxyvinylglycine at 150 ppm and 1-Methylcyclopropene at 25 ppm was more efficient in reducing fruit abscission, increasing fruit weight and yield at harvest plus maintaining firmness, other physical and chemical qualities and prolonging the storability of "Canino" apricots stored at 0 o C for 30 days. Moreover, Martin-Diana et al (2007) reported that, Calcium chloride application was effective to delay fruit ripening, keeping firmness, reduce weight loss and fruit respiration rate.…”

Recent Development in the Preharvest 1-MCP Application to Improve Postharvest Fruit Quality

“…This study showed that treatment not only improved fruit postharvest quality but also lowered the incidence of disorders throughout storage. The combination of the three compounds was the most effective treatment in maintaining fruit quality and prolonging storability up to 30 days [2].…”

“…Ethylene is the simplest natural plant ripening hormone that is involved in the regulation of many growth and development processes of horticultural crops. This hormone acts by linking itself to its action site in the cell to promote a succession of events, such as leaf abscission, fruit maturation, and the ripening process [1][2][3].…”