Bramley’s Seedling – benefits
The effect of SmartFreshTM in retarding scald development is the most commercially significant effect. For long-term storage, SmartFreshSM should be applied within a minimum of 7 days of picking and within the early part of the harvest window. Bramley apples treated with SmartFreshTM and stored in conventional ventilated CA conditions (9% CO2 + 12% O2) should remain free of scald until March and those stored in scrubbed low oxygen (5% CO2 + 1% O2) should remain free of scald until July. For storage up to August, the fruit must be treated within 3 days of picking in the early part of the harvest window and have a dark green background colour.
- SmartFreshTM application consistently improved retention of firmness and reduced weight loss in store.
- SmartFreshTM application provided greener, more acid fruit that were less susceptible to superficial scald and bitter pit.
- Occasional beneficial effects of SmartFreshTM application included higher soluble solids in the fruit and reduced incidence of senescent breakdown and core flush.
- Greatest effects of SmartFreshTM application were achieved on fruit picked at the correct stage of maturity for long-term storage.
- Growers should continue to select for long-term storage those orchards that comply with recommended standards for fruit mineral analysis.
- Regular and rigorous monitoring of the condition of fruit from store is essential and should include a shelf-life test to provide an indication of scald potential.
There is significant orchard variability in the quality of Bramley apples treated with SmartFreshTM (Johnson, 2008) which demonstrates the need to maximise storage potential through attention to pre-harvest factors (see Sections 1, 2 and 3). To minimise scald risk in Bramley there should be no more than 3 days between picking and application and fruit should stored in a scrubbed low oxygen regime.
Bramley’s Seedling – constraints / limitations
Bramley apples are susceptible to external CO2 injury when stored in recommended CA conditions with or without SmartFreshSM.
- It is necessary to delay the establishment of CA conditions in order to alleviate the problem (Johnson et al., 1998).
- Application of SmartFreshTM caused CO2 injury in Bramley apples stored in 5% CO2 + 1% O2 (5/1) despite a 10-day delay in establishing CA conditions.
- For SmartFreshTM treated fruit, it is recommended that the delay in establishing CA conditions is extended to 21 days.
- During this period the oxygen concentration in 5/1 stores can be allowed to decline to 10% but the CO2 concentration should be scrubbed to <1%.
- Delay in establishing CA conditions would normally be considered to conflict with best practice but it is necessary to ameliorate the risk of CO2 injury in Bramley apples.
- The consequences of any delay in terms of reduced storage potential / quality are minimal in SmartFreshTM-treated fruit as the ethylene production and ripening processes are slowed immediately after application.