Seed viability, seed deterioration and seed quality improvements in stored onion seeds: a review

Abstract

ABSTRACTNowadays, the area under onion production through seeds is increasing in India and especially in Tamil Nadu. Onion (Allium cepa L.) seeds are naturally less viable and more hygroscopic than seeds of most common vegetables. Moreover, in most areas, storage of onion seeds in improper or adverse conditions results in a serious problem called seed deterioration, which is characterised by loss of viability, loss of vigour, and loss of seed quality. Therefore, there is a significant demand for quality onion seeds in the seed chain. Hence, here, the literature pertaining to onion seed viability, seed deterioration and seed quality improvements have been reviewed. Scrutiny of the literature reveals that storage of onion seeds at low seed moisture content, low storage temperature and low relative humidity and exploitation of seed invigoration treatments like hydration-dehydration would significantly help in delaying the seed deteriorative processes and, thereby, increasing the viability and longevity of seeds during storage. Importantly, it can be concluded that germinability and vigour of onion seeds can be maintained for more than one year by reducing the seed moisture content to 6 ± 1% and storing them in moisture impervious containers at 4 -15°C and 40 -60% relative humidity (RH).