~ 552 ~ International Journal of Chemical Studies 2019; 7(6): 552-556 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2019; 7(6): 552-556 © 2019 IJCS Received: 28-09-2019 Accepted: 30-10-2019 Manjunath V Balikai Department of Seed Science and Technology, University of Agricultural Sciences, Dharwad, Karnataka, India NK Biradarpatil Department of Seed Science and Technology, University of Agricultural Sciences, Dharwad, Karnataka, India Jagadish Hosamani Department of Seed Science and Technology, College of Agriculture, Vijayapura University of Agricultural Sciences, Dharwad, Karnataka, India MS Biradar Department of Horticulture, University of Agricultural Sciences, Dharwad, Karnataka, India Corresponding Author: Manjunath V Balikai Department of Seed Science and Technology, University of Agricultural Sciences, Dharwad, Karnataka, India Identification of suitable vigour test for onion ( Allium cepa L.) seeds Manjunath V Balikai, NK Biradarpatil, Jagadish Hosamani and MS Biradar Abstract A laboratory experiment was conducted during 2018-19 to identify the suitable vigour test for onion in the Department of Seed Science and Technology, University of Agricultural Sciences, Dharwad. The experiment consisted of 15 seed lots with varied levels of germination and it was laid out in CRD design with four replications. All seed lots were subjected to different vigour tests viz., standard germination, electrical conductivity, radicle emergence, accelerated ageing and field emergence. The results indicated that electrical conductivity (EC) was negatively correlated with field emergence and germination r = - 0.906 and -0.866, respectively. The mean germination time and field emergence was correlated with r = - 0.900. The correlation between electrical conductivity and mean germination time was 0.872. The EC test therefore appears to be suitable for evaluating seed vigour in onion seeds and could be further developed as a rapid vigour test. Keywords: Germination, vigour, electrical conductivity, correlation, onion Introduction Onion (Allium cepa L.) is one of the commercially important vegetables and major among the bulbous crops belongs to the family Amaryllidaceae. Currently, the demand for onion is increasing, mainly due to its nutritive and medicinal value such as antibacterial and antioxidant effects (Doijode, 2001) [4] . The non availability of quality seeds coupled with poor germination and low seedling vigour are the serious problems limiting the production of onion. The use of physiological low quality seeds is a common practice under tropical and sub-tropical conditions leading to inadequate plant population in the field. Further the carry over seeds generally exhibit poor germinability, less vigour and decline in their ability to germinate and emerge into vigorous seedlings leading to problems in successful crop production. Therefore, a reliable estimation of seed vigour is of prime importance to determine the planting value of the seed crop particularly for ones that have poor storage ability like an onion (Yousof et al., 2016) [15] . Different types of vigour tests assess either directly or indirectly the potential performance of the seed lot and provide more sensitive information of a seed lot or between seed lots than the standard germination test. The extensive use of vigour assessments in quality control programme of the seed industry is encouraging (McDonald, 1995) [9] . Seed vigour is an effort to examine the activity and conductance for seed lots of acceptable germination. There are abundant criteria to evaluate seed vigour. This has developed some confusion among growers, seed companies and end users to depict laboratory results. Considering the importance of this subject, it is necessary to establish the relationship amongst some existing and new seed vigour tests for onion and anticipating the storability through these vigour tests. Considering the above factors, the current investigation was carried out with the objective to identify the suitable vigour test for onion. Material and methods Fifteen fresh seed lots of onion variety Arka kalyan having varied levels of germination were collected from Seed Unit, UAS, Dharwad. The seeds were subjected to different vigour tests viz., standard germination, electrical conductivity, radicle emergence, accelerated ageing and field emergence at Seed Quality Research Laboratory, National Seed Project, University of Agricultural Sciences, Dharwad. The experiment was laid out in CRD (Completely Randomised Design) with four replications. The mean data obtained from the experimentation