INTEGRATING IAD INDEX INTO THE CURRENT FIRMNESS-BASED MATURITY ASSESSMENT OF EUROPEAN PEARS
Harvest maturity is the most important factor affecting storage potential and eating quality after storage of European pears. Fruit flesh firmness (FF) is currently the only commercial maturity indicator for harvesting and predicting storage potential of European pears in the US Pacific Northwest (PNW). However, testing FF can be performed on only a few samples due to its destructive nature, and FF often remains constant while fruit continue to mature under high temperatures in certain production years. To study the possibility of fruit peel chlorophyll content as a maturity index, changes in chlorophyll content and IAD index (an estimate of chlorophyll content) determined non-destructively by a portable DA meter were monitored in Bartlett, Anjou and Golden Bosc pears in two years. Bartlett pear FF decreased linearly from ~89 to ~76 N in 2012, but remained constant at ~87 N for ~5 d and then decreased linearly to ~76 N in 2013 during 100-130 DFFB (days from full bloom). Chlorophyll content declined linearly (R2>0.99) from ~50 to ~25 µg g-1 FW and IAD index decreased linearly (R2>0.98) from 2.25 to 1.85 during 100-130 DFFB in 2012 and 2013. Bartlett fruit harvested with IAD: >2.2, 2.2-2.1, 2.1-2.0, and <2.0 showed significant differences in FF, peel green color, and eating quality after 3 months of storage at -1.1°C. IAD may be used as a complementary maturity index with FF for Bartlett pears, but may not be appropriate for Anjou and Golden Bosc due to its small and non-linear decline during maturation or inconsistency between years.
Yan Wang, , Castagnoli, S. and Sugar, D. (2015). INTEGRATING IAD INDEX INTO THE CURRENT FIRMNESS-BASED MATURITY ASSESSMENT OF EUROPEAN PEARS. Acta Hortic. 1094, 525-531
Pyrus communis, maturity index, FF, IAD, storage potential, eating quality