Physical and Physiological Effects of Pre- and Post-Harvest Treatments Using Calcium Chloride and Jojoba Oil on the Guava Fruits Storage

El-Dengawy, El. F. A.; Niamatt-Allah, M. M.; Wanas, A. L. I.; Saima, A. M. A.

doi:10.21608/jpp.2018.36382

Physical and Physiological Effects of Pre- and Post-Harvest Treatments Using Calcium Chloride and Jojoba Oil on the Guava Fruits Storage

Document Type : Original Article

Authors

¹ Department of pomology, Faculty of Agriculture, Damietta University, Egypt.

² Department of Plant Science, Faculty of Science, Damietta University, Egypt.

³ Department of Agric. Botany, Faculty of Agriculture, Damietta University, Egypt

10.21608/jpp.2018.36382

Abstract

The objective of the present research is to find a treatment that preserves the quality of the guava fruits and prolong the marketing period under the room conditions. This study was conducted for two successive seasons 2014-2015 on 18 fruitful and almost identical guava trees at the age of seven years growing in sandy soil at a private commercial guava orchard located in Damietta Governorate - Egypt. The selected trees were subjected to three pre-harvest treatments (3 weeks before harvest time) which involved the foliar spray with tap water (control) or calcium chloride solution at concentration of either 2.5 g/l or 5.0 g/l. After the fruits were harvested at the yellowish green color phase, the fruits of each of the three previous treatments were dipped in water only or 2% Jojoba oil for 5 min and stored under room conditions, at a temperature of (27 ± 1 ° C) and a relative humidity of 70-80%, for 12 days. The effects of the above-mentioned treatments on the physical and physiological characteristics of the fruit quality at the harvest time and at three intervals of 4 days during storage period were studied to get the best treatment for preserving fruits and quality during storage under room conditions. Various fruit quality attributes include the weight loss and decay% of fruits and vitamin C content, acidity%, TSS, total soluble sugars content in fruit juice and also the change in the activity of the peroxidase enzyme in fruit flesh were measured. Most of the tested treatments reduced the weight loss and decay% and the activity of peroxidase in fruit flesh as well as retained the fruits with a significantly higher quality comparing to the control during the storage period until the 12th day. The most effective treatment involved the foliar spray of CaCl₂ before the harvest by 3 weeks followed by dipping the fruits in 2% Jojoba oil after harvest. The fruits of such treatment were more pronounced in their contents of total sugars, vitamin C and TSS/acidity and it also resulted in a reduction in the decay% of fruits to 10.73% after a storage period of 12 days compared to range from 34.2 to 66.6% in other treatments and control.