Preharvest Putrescine Application Extends the Shelf Life and Maintains the Pear Fruit Quality

Pear fruits are climacteric in nature and remain biologically active due to continuous respiration, transpiration, and other biochemical processes even after harvest. Under ambient conditions of north-western India, pear fruits have a short shelf life. An experiment was conducted to enhance the shelf life of pear fruits cv. Punjab Beauty using preharvest sprays of putrescine (PUT) @ 1 mM, 2 mM & 3 mM. Mature fruits from PUT treated and control plants were harvested and stored at ambient conditions (32 +/- 2 degrees C, 78 +/- 5% RH). Periodical observations for various physicochemical parameters and enzymatic activities were taken on 0, 3, 6, 9, 12 and 15 days after ambient storage. As compared to control, 2 and 3 mM PUT treatments resulted into a reduction in weight loss (WL), spoilage along with retention of higher firmness, soluble solid content (SSC), titratable acidity (TA), and starch content in stored pear fruits. During storage, these treatments had also reduced the fruit softening by reducing the activities of cell wall degrading enzymes like pectin methylesterase (PME) and cellulase. So, it could be inferred that PUT treatment of 2 mM & 3 mM was effective to enhance the shelf life of pear fruits at ambient conditions with acceptable quality.