Pre and Post-Harvest Treatments to Improve Ponkan Mandarin Fruits Quality 1. Maintaining Fruit Quality during Cold Storage

Abstract

Ponkan mandarin (Citrus reticulata, Blanco) occupies a prime position among the mandarin species cultivated in Egypt, owing to its high productivity and early yields as well as fruits have a high nutritive value. Despite its attributes and commercial importance, Ponkan mandarin fruits cannot be sustained for a long period due to its poor shelf life. So, the present study was conducted during 2017 and 2018 seasons on 10 years old trees, grown in clay soil at the experimental farm of Faculty of Agriculture, Kafr El-Sheikh University, Egypt, to evaluate the effect of putrescine at 0, 50 and 100 ppm as pre-harvest treatments individually or combinations with salicylic acid at 0, 200 and 400 ppm as post-harvest treatment on fruit properties during cold storage at 5±1 °C and 90 - 95 % RH for 90 days.The obtained results revealed that pre and postharvest treatments of putrescine and salicylic acid enhanced achievment fruits with acceptable qualities during cold storage period as compared to control. The combination treatment of putrescine pre-harvest spraying at 50 ppm plus salicylic acid post-harvest dipping at 400 ppm (T7) was more effective on fruit quality such as fruit weight loss, decay, firmness, SSC%, acidity, SSC/acid ratio and vitamin C during cold storage. Therefore, putrescine and salicylic acid treatments have capability to avoid post-harvest and storage losses along with enhancing quality of the stored fruits.