on the growing crop (Goodliffe and Heale, 1975). If the crop remains
in the soil over the winter (e.g., storage of carrots by “strawing over”),
the tissue will provide a substantial protection against pathogens. Har-
vest and subsequent storage normally damage the tissue and wound heal-
ing is often incomplete or delayed. The presence of various antifungal
compounds in carrot with the highest concentration in the peripheral tis-
sue at harvest (Olsson and Svensson, 1996) may explain why latent in-
fections are progressing slowly during the first 3–4 months of storage.
After this period of time, tissue resistance seems to decline and proba-
bly coincides with the termination of vernalization. Investigations into
the nature of natural resistance against storage diseases therefore de-
serves further attention.
CONCLUSION AND FUTURE RESEARCH NEEDS
Research on the postharvest physiology and technology of fruit and
vegetables in the last 20 years has led to many significant advances, with
particular emphasis on improving appearance in the market place. Meth-
ods for produce handling and retailing are becoming more and more so-
phisticated. A challenge for the future will be how to integrate scientific
results into commercial activities in the postharvest chain. While scien-
tists are interested in determining the most suitable temperature or mod-
ified atmosphere for maintaining the shelf life of a certain product,
distributors and retailers are often more interested in maintaining higher
quality items within an acceptable shelf life.
Vegetables are sold according to their attractiveness and therefore
must be exposed to the consumer in a way that normally does not allow
proper temperature control. Possibilities for evaluating freshness, matu-
rity and absence of blemishes before deciding on purchase are required
by many consumers. Information about the origin of the produce, i.e.,
local production or import, as well as growing methods is also of in-
creasing concern. Concomitantly, the enhanced use of trade-marks in
vegetable marketing and consumer packaging is aimed at helping con-
sumers to make the proper choice. Vegetables packed in a polymeric
film and displayed in cool cabinets are therefore often considered as
more suspect and less natural and environment-friendly than those dis-
played in open boxes. For supermarkets with a high daily turnover there
should be no problem in fulfilling such needs but for small retailers this
is hardly possible.
The growing interest in ready-to-use vegetables appeals to another
Conclusion and Future Research Needs 115