EFFECT OF STORAGE METHODS ON THE QUALITY OF ONION BULBS

Abstract

An experiment was carried out to determine the effect of storage methods on quality of onion bulbs. The fresh bulbs of Nasarpuri variety free from defects and of uniform in size were purchased from local market and were properly cured. The bulbs were stored under three different storage methods including (i) wooden packed structure on raised platform fully ventilated having bottom and sides covered with rice straw, (ii) nylon net bag and (iii) open ground fully ventilated from all sides. The parameters studied were physiological loss in weight (%), sprouting (%), sprout length (cm), pathogen/fungi (%), rotting (%) and black mold (%). Dry and wet bulb thermometers were installed for measuring ambient temperature and relative humidity during the study. The onions were stored for three months and data were recorded at an interval of 15 days. The results revealed that the highest physiological weight loss (10.40%) was observed under open ground method, followed by nylon net bags (8.54%), while lowest physiological weight loss (4.19%) was recorded under wooden packed structure ventilated from all sides. The maximum % age of pathogen/fungi  was observed under open ground (16.25%), followed by nylon net bags (11.24%), while minimum % age of pathogen/fungi was witnessed under wooden packed structure (7.91%). Minimum black mold (%) was observed under wooden packed structure (3.23%), while maximum black molds  were recorded under open ground (17.50%), followed by nylon net bags (13.33%) during 90 days of storage. It was also observed that during 90 days of storage, sprouting and rotting didn’t occur under any of three storage methods.  It is concluded that the wooden packed structure ventilated from all sides on raised platform proved better in providing the desired environment to onion bulbs during 90 days of storage. Therefore, this study suggested that the wooden packed structure ventilated from all sides on raised platform is more effective in reducing the deterioration of onion bulbs during three months of storage.