Investigating internal browning of Tasmanian ‘pink lady’ apples
G. Brown, L. Schimanski and D. Jennings
ISHS Acta Horticulturae 628 : 161-166
2003
บทคัดย่อ
Due to internal browning of ‘Pink Lady’ apples after storage and transport to markets, an investigation was conducted with thirteen lines from Tasmania by assessing incidence of internal browning, fruit quality measurements, fruit nutrient levels, fruit storage atmospheres and growing conditions in the orchards. Field trials and post harvest trials were established to ascertain the relative importance of the probable causal factors identified in the initial investigation. A large variation in the incidence of internal browning with 4 lines of fruit expressing less than 10% browning and 5 lines with greater than 40%. Affected lines were stored in low CO2 (1.3%) and low 02 (1.98%) conditions. Fruit lines with a low incidence of the problem had been stored in higher CO2 (2.03%) and O2 (2.25%) atmospheres. The level of tree vigour was also related to the incidence of the problem with vigorous trees being associated with a low incidence of internal browning. Non vigorous trees such as those on dwarfing rootstocks, on poor soils, or with heavy summer pruning and girdling were associated with an increase in the incidence of the problem. The lines of fruit with greater than 40% internal browning had significantly higher levels of fruit zinc. It should be noted that 4 of the 5 worst lines had received a zinc foliar spray compare with 1 in the best 4 lines of fruit suggesting that this activity is detrimental to fruit quality.