~ 925 ~ Journal of Pharmacognosy and Phytochemistry 2020; 9(5): 925-932 E-ISSN: 2278-4136 P-ISSN: 2349-8234 www.phytojournal.com JPP 2020; 9(5): 925-932 Received: 17-06-2020 Accepted: 24-07-2020 Sivaji Sivasakthi Ph.D Scholar, Department of Seed Science and Technology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India Jayakumar Renugadevi Professor, Department of Seed Science and Technology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India Corresponding Author: Sivaji Sivasakthi Ph.D Scholar, Department of Seed Science and Technology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India Appraisal of storage potential of onion cv. CO (On) 5 seeds under carbon dioxide and ambient storage condition Sivaji Sivasakthi and Jayakumar Renugadevi DOI: https://doi.org/10.22271/phyto.2020.v9.i5m.12351 Abstract The laboratory experiment was conducted to study the storage potential of onion seeds under ambient and carbon dioxide (CO2) conditions. The onion seeds were given with different treatments such as T1- Control, T2-Seed coating formulation-I (SCF-I)-10g/kg, T3-Seed coating formulation-II (SCF-II)-10g/kg and stored in cloth bag under ambient condition and plastic container under CO2 condition (30% CO2) for six months. The seed samples were drawn at monthly intervals and evaluated for the seed and seedling quality parameters. The result revealed that, seeds coated with SCF-II and stored under CO2 condition recorded the highest germination rate and seedling vigour; dehydrogenase, α-amylase, catalase and peroxidase activity; protein and oil content; lowest electrical conductivity and pathogen infection after six months of storage compared to other treatments and ambient storage. It can be used effectively to enhance the seed quality and particularly beneficial in the absence of cold storage facility and in addition it can be used for maintaining seed quality for long period. Keywords: Onion, seed coating formulation, storage condition, seed storage, seed quality 1. Introduction Good seed is a basic input in vegetable production. The production of vegetable seeds is a costly venture and the possibilities of carrying over the left over stock for more than one season possess a serious problem, because seeds deteriorate during storage. Wastage of seeds is highly regrettable because of their high economic value. Prolonging the shelf life of stored seeds is always a profitable and can be adopted if the procedure is cheap and easy to follow. Seed production in onion is very specific with season; it necessitated the storage of seeds until used for sowing. In order to prevent the quantitative and qualitative losses due to biotic and abiotic factors during storage, several seed enhancement techniques are being adopted. Seed coating is an effective enhancement technique results in uniform deposition of an extremely thin film on the seed surface, multiple coatings of various ingredients are also possible (John et al., 2005) [1] . Seed coating formulations may contain plasticizers, colorants and other ingredients that are commercially available in aqueous suspensions. The benefits of film coating include uniform placement of protective materials very precise amounts and with a minimal impact on the environment (Baudet & Peres, 2004) [2] , enhanced appearance due to the addition of pigments and an excellent delivery for seed treatment chemicals (Taylor et al., 2001) [3] . Film coating is routinely performed by the seed industry on high-value seeds such as vegetables and flowers. Seed coating protects the seed from various stress imposed during storage including fungal invasion. Onion seeds are very poor in storage (Nagaveni, 2005) [4] . It loses its viability and vigour more rapidly after harvest than the seeds of other crops unless special precautions are taken in its storage. It is well known fact that the choice of materials for seed treatment, containers selected for storing the seeds and storage environment exert a positive effect on the viability and vigour of seeds in storage. CO 2 storage is modified atmospheric storage condition in which carbon dioxide is added to a storage container of seeds in an effort to replace oxygen with the carbon dioxide. The idea is that the lack of oxygen will increase the seed storability by slowing down the respiration rate of the seeds, allowing them to remain dormant longer. Carbon dioxide is heavier than oxygen, so introducing it into a container replaces the oxygen by gravity. This may also have the additional advantage of killing any insect pests which may be present, as the insects also require oxygen to respire and survive (but at a greater quantity than seeds). Hence, an attempt was made to know the effect of seed treatment and storage condition on seed quality parameters of small onion cv. CO (On) [5] .