Extending harvest season and enhancing shelf life of navel oranges by preharvest treatments with different bioregulators.

摘要

The present study was conducted in 2008/2009 and 2009/2010 seasons in order to extend shelf life of navel orange fruits at harvest and after cold storage by preharvest foliar sprays with GA₃, 2,4-D, putrescine and calcium either alone or in combinations. Trees were harvested in two different harvest dates, the first was at the estimated commercial harvest date (middle September) and the second late in the harvest season (during February). At both harvesting dates, a fruit group was held at room temperature (RT, 20 degrees C) for ten days and another group was stored at 8 degrees C and 85-90% relative humidity for one month and then kept at RT for one week in order to investigate fruit shelf life. All sprayed substances had a significant influence in decreasing fruit softening, postharvest rind staining, decay and the number of fruit unfit for marketing during held at room temperature for the fruits after harvest or after cold storage. Also, fruit total soluble solids and vitamin C contents were increased as compared with untreated control trees. The sprayed substances improved keeping quality of navel oranges during held at room temperature for the fruits after harvest or after cold storage.