Storage potential of bulb onions (Allium cepa L.) under high temperatures

SummaryThe effects of constant high temperatures of 25 and 307C in comparison with a low temperature storage regime at 2&C were investigated on storability of two bulb onion (Allium cepa L.) cvs. Texas Early Grano and Dorcheh (an Iranian cultivar) under 65–75% relative humidity for a period of 270 days. In both cultivars, sprouting of onion bulb is inhibited at high storage temperatures as a result of significant reduction in the relative growth rate of sprout leaves within the bulbs, compared with low-temperature storage at 2&C treatments in both cultivars, and onions became nearly dormant. Onion cv. Texas Early Grano maintained marketability at temperatures of 25 and 30&C for periods of three and two months, respectively. During the first 3–4 months of storage at these high temperatures there was no significant change in pH, total soluble solid (TSS) and titratable acidity of the bulbs contents, compared with a low temperature of 2&C for both cultivars. However, over longer periods, rotting and desiccat...