1983 Volume 52 Issue 3 Pages 325-331
Ripening changes in respiration rates, ethylene emanation, flesh firmness and color development of plum (Prunus salicina Lindl.) fruits were investigated using 3 cultivars of‘Ooishi Wase’, ‘Beauty’and‘Santa Rosa’. The fruits were picked 2_??_6 times at different stages of maturity and stored at 20°C.
Respiration rate on the tree, which was estimated by measuring the CO2 output of the fruit 24 hours after harvest, showed a climacteric pattern in all of the 3 cultivars.
In early maturing cultivars (‘Ooishi Wase’and‘Beauty’), the rise of respiration rate occurred earlier and progressed more rapidly than that of late maturing cultivar (‘Santa Rosa’).
The changes in respiration rate during 20°C storage were different with the stages at harvest in all of the 3 cultivars. That is, there were no respiratory climactric rise nor rise in ethylene emanation, unless the fruits were harvested at and after climacteric minimum on the tree.
In‘Ooishi Wase’and‘Beauty’, the climacteric rise advanced rapidly with red color development and softening of flesh, while in‘Santa Rosa’, the climacteric rise and softening of flesh advanced much more slowly than color development.
The free abscisic acid content of attached fruits increased with the rise in respiration rate during ripening on the tree.
That of detached fruits also increased even when the fruit was harvested earlier and showed no climacteric rise during storage.
The fruits treated with 500ppm ethylene for 48 hours after harvest did not induce a respiratory climacteric, an ethylene rise nor hastening of ripening, unless they were harvested at and after climacteric minimum.