Use of evaporative cooling to improve ' Rosemarie' and ' Forelle' pear fruit blush colour and quality
Date
2005-04
Journal Title
Journal ISSN
Volume Title
Publisher
International Society for Horticultural Science -- ISHS
Abstract
In Pyrus communis ‘Rosemarie’, a potentially lucrative blushed pear cultivar,
poor fruit colour has been ascribed to pre-harvest red colour loss during periods of
high temperature. High temperatures combined with high irradiances also lead to
sunburn on pome fruit. The use of pulsed overhead evaporative cooling (EC) to
improve red colour and reduce sunburn in two blushed pear cultivars was evaluated
over four seasons (2000/01 to 2003/04) in Stellenbosch, South Africa. ‘Rosemarie’
fruit blush was usually but not always improved under EC, with a late application
(starting two weeks before harvest) yielding the best improvement. Peel anthocyanin
concentrations were increased under EC. Incidence of sunburn was reduced during
some years, but increased in EC-treated fruit during 2003/04 due to system failure
on a hot day. EC initiated early in fruit development initially led to larger fruit with
a lower TSS concentration and firmness, but this effect was gradually eliminated
following reductions in EC water use. EC had no effect on ‘Forelle’ pear fruit colour
or mass, but reduced firmness and TSS when started early in the season. Sunburn
was only recorded in EC-treated fruit during 2002/03 due to system failure on a
warm day. Though EC could be used to improve ‘Rosemarie’ fruit colour in warm
production areas, its effect was relatively small compared to colour change in
response to fluctuating temperature. The increased risk of sunburn during system
‘downtime’ highlights the requirement for a highly reliable system.
Description
The original publication is available at http://www.actahort.org/books/671/671_12.htm
Keywords
Pears -- Effect of temperature on, Pears -- Postharvest technology, 'Forelle' pears -- Quality, 'Rosemarie' pears -- Quality
Citation
Wand, S. J. E., et al . 2005. Use of evaporative cooling to improve ' Rosemarie' and ' Forelle' pear fruit blush colour and quality. Acta Hort. (ISHS), 671:103-111.