Onion genotypes Red Cereole, followed by Katarina Red 3 and Katarina Red 7 are superior with respect to post harvest quality parameters

Abstract

Onion bulbs of long-day genotypes, viz. Red Cereole, Katarina Red 3, Katarina Red 7, Supreme, Cyrus, Lock Roy, Legend, Wall Brown, Brown Spanish, and a local cultivar were stored for 50, 100, and 150 days in a controlled atmosphere at 2± 1 °C and 75±1% relative humidity. The experiment was laid in a randomised block design with three replicates. Dry matter, TSS, hardiness of bulb, total sugar, non-reducing sugar, and reducing sugar loss in weight (%), rotating (%) sprouting (%), sprout length (cm), incident black mold (%), and marketable bulbs (%) were recorded throughout the storage period. In all genotypes, dry matter, TSS, total sugar, and non-reducing sugars, rotting (%) sprouting (%), sprout length (cm), and incidence of black mold increased gradually during storage. In contrast, hardiness/firmness of bulb, ascorbic acid, reducing sugar, physiological losses in weight, marketable bulbs decreased gradually during the storage period. Similar patterns of increase and decrease in all the observed traits were observed for all the genotypes. Furthermore, at the genotypic level, significant variation was observed in storage potential. The genotypes Red Cereole, Katarina Red 3, and Katarina Red 7 were superior to many of the post-harvest traits. They gave the highest marketable bulb at the end of storage. Therefore, it is concluded that onion genotypes Red Cereole, Katarina Red 3, and Katarina Red 7 have good storage potential that could be stored overwinter at high altitudes. Therefore, it is recommended to cultivate these onion genotypes for long-term storage in temperate regions.