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Advances in research and technology in recent years in the field of controlled atmosphere (CA) storage have led to the development of many new protocols that recommend lower oxygen (02) levels than those historically deemed "safe". As some of these protocols and technologies have been adopted by commercial CA storage rooms, especially in the apple industry, it is now opportune to review the relationships between O2 levels, respiration, fermentation, and fruit quality retention. Lowering O2 levels during apple storage slows respiration, reduces ethylene biosynthesis, and slows fruit maturation and senescence. In addition, low O2 influences the expression of genes associated with cellular energy consumption. When O2 levels become limiting, aerobic mitochondrial respiration is inhibited and plant tissues engage in the energetically less-efficient fermentation pathway. The accumulation of fermentation-related volatiles may lead to off-flavours and odours. At low levels, or for short durations, fermentation is generally not a problem and may even be commercially beneficial. Plants that are limited in their ability to ferment succumb to low-O2 stress more quickly than those that can readily ferment anaerobically. Increasing market pressure to reduce chemical residues in apple, as well as in all fruits and vegetables, is encouraging researchers, CA system manufacturers and suppliers, and some commercial storage operators to explore alternative methods to improve storage procedures. The future of CA storage may reside in a better understanding of what constitutes the lower O2 limit for metabolism and energy demands, improved product-response sensing capabilities, and the application of more dynamic forms of CA storage technology. [ABSTRACT FROM AUTHOR]

Several pre-storage time (0, 1, 2, 4, and 6 d) and temperature (3.5°, 100, 15°, 20°, 25°, and 30°C) delayed cooling (DC) treatments were tested on harvested 'Honeycrisp'™ apples to determine which combination was optimal for reducing soft scald and low temperature breakdown (LTB), while maintaining the highest fruit quality [i.e., firmness, minimal mass loss, titratable acidity (TA), soluble solids content (SSC), absence of rot, and minimal skin greasiness] after 4 months of refrigerated air (RA) storage. Fruit were harvested from three separate Annapolis Valley (Nova Scotia) orchard sites in 2006 and in 2007. Multiple linear regression and surface response curves showed that fruit firmness and SSC generally increased throughout the DC treatment, but were affected curvilinearly by temperature, reaching a maximum at approx. 15°C, then declining. Loss of fruit mass was positively related to a (day x temperature2) interaction, indicating that it increased synergistically the longer and the warmer the DC treatment. Fruit acidity was affected only by temperature, with the highest TA values at approx. 15°C, then declining at higher DC temperatures. Multiple logistic regression and surface responses demonstrated that the incidence of soft scald declined curvilinearly the longer and the warmer the DC treatment, while LTB declined curvilinearly with increasing DC temperature only. A positive (day2 x temperature2) interaction indicated that fruit greasiness increased non-linearly as the duration and temperature of DC increased. Collectively, these results show that both soft scald and LTB were suppressed or eliminated by a DC regime of 25°C for 1 -2 d, or 30°C for 1 d, without incurring a major reduction in fruit quality. [ABSTRACT FROM AUTHOR]

The influence of three manually-adjusted crop loads [3, 6 and 9 fruit cm-2 trunk cross-sectional area (TCSA)] on ‘Honeycrisp’™ apple (Malus domestica Borkh) quality and canopy volume were compared with unadjusted control trees, q-he crop-load treatments were applied at three sites over two consecutive seasons at 50 days after full bloom (DAFB). Sixteen trees at each site were selected annually, with the treatments being applied in a randomised-complete-block design. Fruit mass and fruit colour (%) were used to assess quality at harvest, while yield was determined by the mass (kg) of fruit cm-2 TCSA. The canopy volume (CV) for each tree was calculated following harvest and used as a covariate in determining its influence on fruit size and colour. As crop load decreased, harvested fruit mass and % red colour increased. For similar crop-load adjustments, larger tree CVs (in m³) resulted in greater fruit mass. Crop load and fruit-canopy density (fruit m-3 CV) were more highly correlated with fruit mass than with % fruit colour. The highest fruit quality occurred at the three and six fruit cm-2 TCSA. In addition, manually adjusting the crop-load at 50 DAFB did not eliminate the disposition of ‘Honeycrisp’™ towards biennial bearing in Nova Scotia's climate. [ABSTRACT FROM AUTHOR]

Potato production in Sri Lanka has been increasing since the importation of tablestock was stopped in 1967. Production is now successfully established in four regions: Nuwara Eliya, Badulla, Jaffna and Puttalam. Average yields are ca. 16 T/ha but can reach as high as 40 T/ha. Production still depends on the importation of seed potatoes which are then multiplied under a government program. In order to reduce the cost of seed, which can be up to 50% of the cost of production, a true seed program has been instituted. Weather, poor storage conditions, varying availability of good seed and diseases are the major problems limiting potato production in Sri Lanka. Significant reductions in production and storage problems will be realized with the continued efforts of the Sri Lankan government and international agencies. [ABSTRACT FROM AUTHOR]