Post harvest Management of Horticultural Crops (2+1)

Susceptibility of harvested produce

Susceptibility of harvested produce to low storage temperature stress may be improved by practicing fallowing methods:

• Lowering the temperature in steps from 3oC down to 0oC in the first month of storage (i.e. step-down low-temperature conditioning) can minimize the development of low-temperature breakdown and soft scald in apple.
• Low-temperature breakdown of apple and stone fruits can also be reduced by periodically raising the temperature to around 200C for a few days during the storage period called intermittent warming. This method is not been widely adopted in commercial practice because of the logistical problems of having a room full of uniform produce ready to treat at one time (different batches of fruit in a storage room) and the difficulty of rapidly changing the temperature of a room full of fruit. Another issue is that transient increase in the storage temperature will shorten the storage life of any produce held in the same room that is not susceptible to the particular disorder (e.g. other varieties).
• Relatively brief periods of pre-storage exposure to intermediate low temperature (i.e. low-temperature conditioning)
• High-temperature stress (e.g. hot air, hot water dipping, hot water brushing)
• Warm temperature and high RH condition (i.e. curing)
• Nitrogen atmosphere (i.e. anoxia) has also proven beneficial in terms of reducing produce susceptibility to various low-temperature injuries.
• The pre-harvest temperature regime (i.e. periods of high or low temperature up to harvest) significantly influences postharvest susceptibility to low-temperature injury and response to conditioning treatments.