Exogenous ethylene shortens the prerequisite cold storage period for normal ripening of Forelle pears
Toit, P. G. du, Huysamer, M., Jacobs, G. and Holcroft, D. M.
Acta Hort. (ISHS) 553:181-184.
2001
บทคัดย่อ
In 1998, pear cv. Forelle fruits were harvested at commercial maturity and treated with ethylene at concentrations of 0, 10 and 100 micro litre/litre for 24 h at 20 deg C. In 1999, fruits were treated with 50 micro litre ethylene/litre for 12, 24 and 36 h at 20 deg C. Control fruits were held at 20 deg C for 24 h. Ethylene at 10 and 100 micro litre/litre reduced the cold requirement of Forelle from 10 to 4 weeks as evidenced by changes in skin colour from green to yellow. Fruit firmness was not affected by ethylene treatments when stored at -50 deg C, but when fruits were moved to 20 deg C differences were observed. After 4 weeks at -50 deg C and 7 days at 20 deg C ethylene-treated fruits softened rapidly, but after 6 weeks at -50 deg C and 7 days at 20 deg C there were no discernible differences between the control and treated fruits. These changes were accompanied by favourable changes in total soluble solids and titratable acidity. Fruits treated with 100 micro litre ethylene/litre were not significantly different from those treated with 10 micro litre/litre. Fruits treated with 50 micro litre ethylene/litre for 24 and 36 h reached the minimum colour requirement of 3.5 after 6 weeks at 0 deg C followed by 7 days at 20 deg C. The untreated control required 12 weeks at 0 deg C followed by 7 days at 20 deg C to exceed the minimum colour requirement of 3.5. The differences in firmness between ethylene-treated fruits and control fruits were no longer discernible after 8 weeks at -0.5 deg C and 7 days at 20 deg C. Firmness of fruits held at -0.5 deg C was not adversely affected by ethylene, consequently treated fruits can be stored for the same period as untreated fruits. Observations indicated that minimal mealiness occurred, and it was correlated with advanced maturity.