30 July 1984 Controlled atmosphere techniques for storage of nectarines could extend export opportunities

Using controlled atmosphere techniques for storage and transport of nectarines could widen export potential on distant markets, but the technology offers fewer advantages for apples and kiwifruit, according to a research report published by the Agricultural Economics Research Unit at Lincoln College.

Research into the economics of CA storage of nectarines, apples and kiwifruit was carried out by research. economists Mr M.T. Laing and Mr R.L. Sheppard, of the A.E.R.U.

Advantages of using CA technology vary because of the different markets and marketing systems for the three fruits.

CA sea transport of nectarines has the potential for reducing transport costs to present markets to which the fruit is air freighted.

Other markets for nectarines could be developed that are presently too expensive for air freight and too far away for sea transport.

The time taken to ship to some markets is presently beyond the storage life of nectarines.

Estimated net revenue gains could absorb the higher costs of CA storage and transport, the report says.

However, CA storage and transport of apples presently offers little advantage to New Zealand.

Largely this is because the N.Z. export season already overlaps domestic apple harvests in northern hemisphere importing countries.

Even on those markets where domestic production is not important, competition for N.Z. apples comes from other Southern Hemisphere~ suppliers.

However, apples stored and transported under CA would arrive on export markets in better condition than if shipped conventionally.

Whether the higher-quality fruit would fetch better prices would depend on the competition for apples at the time.

More immediate and certain gains would come from CA on the domestic market by maintaining quality longer.

Both the N.Z. Apple and Pear Marketing Board and gate sellers could get more for each carton through using CA storage for end of year supplies.

But gate sellers rather than the Board have an incentive to develop more CA storage so they can extend their selling season.

All potential markets for kiwifruit can be served by using lower-cost sea transport because of the storage life of the fruit under conventional cool storage.

CA advantages for kiwifruit could come from extending the packing season from the present six weeks to 16 weeks.

Presently nearly all kiwifruit are graded and packed within 48 hours of harvesting during the six-week harvest.

However, between now and 1990 there is expected to be an increase in production of more than 600 per cent, so extending the packing season will become important.

Handling this increased output within the present six-week harvest using conventional systems would mean heavy costs in building more grading and packing facilities.

Extending the packing season to 16 weeks using a carbon dioxide-air CA for storage would be quite simple technically.

Rigid CA cool stores could be built, or flexible plastic tents erected in conventional cool stores could be used for CA.

Both these methods would allow a 10-week extension to the packing season, and building new grading and packing facilities would not be necessary.

However, even greater savings could be made by using high-humidity bulk cool storage and extending the packing season by four weeks to 10 weeks.

High humidity is a significant factor in the CA allowing the packing season to be extended.

Using high-humidity storage could reduce investment costs by nearly 16 per cent,or $28.5 million, over other options.

High-humidity storage has economic advantages over CA, but there are other even more economical options.

Among these is making better use of existing facilities by introducing double shifts and weekend work to replace the single-shift to handle the expected increase in the kiwifruit crop.

Further information from Mr Ron Sheppard, Agricultural Economics Research Unit, Lincoln College, Canterbury, New Zealand.