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- Author or Editor: R. R. Dedolph x
- Journal of the American Society for Horticultural Science x
Abstract
A continuous gas flow system is described which utilizes a paramagnetic O2 analyzer and an infra-red CO2 analyzer to automatically sample, analyze, and record respiratory gas exchange of plant material. The system monitors gas exchange of up to 96 plant samples sequentially, repeatedly, and over extended time periods.
Abstract
The production of CO2 by apple and pear fruit was measured during and after alternating 12-hr exposures to air and N2 atmospheres. Typical stimulation of CO2 evolution in the absence of O2 was observed. Five or more anaerobic cycles imparted a permanent reduction on the subsequent aerobic respiration rate. The differences between control respiration and aerobic CO2 evolution by fruit exposed to cyclic anaerobiosis indicated that the capacity for aerobic respiration was reduced by the early anaerobic cycles. Suppression of the anaerobic stimulation of CO2 production was observed after several cycles suggesting that the capacity for fermentation was accumulatively impaired. Subsequent measurements of physical characteristics showed that flesh softening and chlorophyll degradation, processes which generally coincide during ripening, were differentially affected by cyclic anaerobiosis. Apple scald was induced by anaerobiosis. Pear fruits subjected to anaerobic cycles or continuous anaerobiosis did not ripen during the 14-day poststorage period at 21°C.
Abstract
Rest period reduction in non-stored onion (Allium cepa L.) sets is favored by post-harvest temperatures of 5° and 25°C for periods of 1 to 10 days. A short-term post-harvest temperature of 45°C favored rest period reduction, but periods over 24 hr at 45° did not reduce the rest period. Reduction of sprouting attributable to the 45° storage was more pronounced with the White Portugal cultivar than with Yellow Ebenezer. Zero to 800 rad gamma irradiation (of freshly harvested sets) did not influence time of sprouting but doses from 1,600 to 12,800 rad decreased sprouting. Potassium gibberellate (A3)(applied as a dip treatment on sets) increased weights of plants grown from sets stored at 5°C for 72 hr before planting. High post-harvest storage temperatures (45°) negated the subsequent growth promoting effects of GA. Application of these findings has resulted in commercial shipments of freshly harvested onion sets under refrigeration.