Effects of maleic hydrazide and temperature on onion quality during storage
M. EI-Otmani, A. Ndiaye, A. Ati-Oubahou and A. Kaanane
Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-104. pp. 250.
2002
บทคัดย่อ
In subtropical regions, loss of quality in onion bulbs (Allium cepa L. ) is of great concern. Postharvest losses can be as high as 40% of total production or more and are due essentially to germination, decay, rooting and weight loss. Preharvest as well as postharvest factors such as temperature, humidity, cultural practices. In this work we investigated the effect of foliar application of maleic hydrazide (MH) at 0, 3000, 6000 and 9000 ppm applied 15 days prior to harvest on quality of ‘Rouge d’ Amposta’ onions during storage for 6 months at 3 0C, ambient temperature in a dark room and in traditional silos made with rock walls and straw. Dry matter content of the onions was in the range of 8-10% with no significant effect of either MH, temperature or method of storage (silo vs. ambient temperature). Weight loss was significantly inhibited by cold temperatures; germination was inhibited by MH and cold temperature; decay was reduced by cold temperature and MH; and rooting was reduced by MH but temperature. After 6 months of storage, values of 72,78 and 85 umol of thiosulfinate/g dry matter were recorded, respectively, for storage at cold temperature, ambient temperature and traditional silo. MH had no effect on aroma. MH residues in the bulbs did not vary during storage but were always highest (403-5.0 ppm) for 9000 ppm and lowest (0.4-0.7 ppm) for 3000 ppm. The significance of these results for subtropical regions will be discussed.