Contents lists available at ScienceDirect Biocatalysis and Agricultural Biotechnology journal homepage: www.elsevier.com/locate/bab Chaetomorpha antennina (Bory) Kützing derived seaweed liquid fertilizers as prospective bio-stimulant for Lycopersicon esculentum (Mill) Kanagaraj Muthu-Pandian Chanthini, Sengottayan Senthil-Nathan ∗ , Vethamonickam Stanley-Raja, Annamalai Thanigaivel, Sengodan Karthi, Haridoss Sivanesh, Narayanan Shyam Sundar, Radhakrishnan Palanikani, Ramaiah Soranam Sri Paramakalyani Centre for Excellence in Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi, 627 412, Tirunelveli, Tamil-Nadu, India ARTICLE INFO Keywords: Bio-fertilizer Seed priming Seedling vigour Vegetative growth Fruit biochemistry EDX ABSTRACT Plant nutrition serve as critical factors that influences plant growth and yield. Global fertilizer production and application is growing in surplus amounts, increasing the agricultural expenses and damaging the environment. Organic fertilizers, obtained from natural sources, encompass all essential plant nutrients. Application of aqu- eous seaweed extracts are regarded as potential plant biostimulant agents. The liquid seaweed extract of green seaweed Chaetomorpha antennina (CA-LSE) were evaluated for their biostimulant activity on seed germination and growth of tomato. The CA-LSEs were able to stimulate early emergence of tomato seeds, in addition to increasing their germination percentage and energy. They also exerted a positive influence on the vegetative growth, resulting in increased plant height, leaf-branch number and yield. The CA-LSEs were influence the plant's biochemical profile and displayed a linear increase in pigment contents (chlorophyll a & b and car- otenoids), total soluble solids (TSS), phenols as well as ascorbic acid contents. The bio-stimulant potential was attributed to the elements present in CA-LSEs, elucidated by EDX analysis that revealed the presence of six elements (O, Na, Mg, S, Cl and Ca), that were essentially plant nutrients. These results support the bio-stimulant potential of C. antennina, which can be applied as a prospective bio-fertilizer that is economic, renewable, efficient and eco-friendly, and also can be regarded as a potential catalyst for the betterment of sustainable agricultural food production. 1. Introduction Plants are immobile organisms henceforth; they cannot avoid ex- treme environmental conditions. The biotic and abiotic stressors are jeopardizing them from attaining their complete genetic potential, consequently affecting world crop production (Gill et al., 2011; Senthil- Nathan, 2013). The increasing mean global temperature rise is creating a negative impact on the production of horticultural crops (Singh et al., 2016; Senthil-Nathan, 2015). The mineral nutrient status of plants serve as critical factors that determines plant growth, vigour besides crop yield and these nutrients play a particular role in contributing to the survival of crop plants under environmental stress conditions (Hassan et al., 2008). Meant for healthy besides vigorous development, it is essential for plants to take up large quantities of major nutrients (ni- trogen, potassium and phosphorus) and minor amounts of micro nutrients (iron, nickel, chromium, manganese, zinc, boron, copper and molybdenum) from the soil (George et al., 2008). Global fertilizer production has reached an overwhelming quantity of 207.98 MT annually. This increase is attributed to the application of higher amounts of fertilizer per unit area (23kg/0.23 ha) (FAOSTAT, 2014). Further complications have arisen with the disproportionate increase of fertilizer application – grain land ratio, over the years. This has subsequently not only up surged the production costs, but also has degraded the environment to the extent that the soils are becoming unfit for agriculture. As a paradox, these economic expenses did not go in par with the income or yield, thus increasing the financial burden of farmers worldwide (Sunarpi et al., 2010). And so, the determinations to capitalize on the plant nutrient absorption by means of natural products that comprehends all plant nutrients, is a premeditated approach to subdue the applications of inorganic fertilizers (Naguib, 2011). These https://doi.org/10.1016/j.bcab.2019.101190 Received 6 May 2019; Received in revised form 31 May 2019; Accepted 1 June 2019 Abbreviations: CA, Chaetomorpha antennina; LSE, Liquid Seaweed Extract; EDS, Energy Dispersive Spectroscopy; EDAX, Energy Dispersive Analysis X-Ray; SFS, Starter fertilizer solution; CF, Chemical fertilizer; MGT, Mean Germination time; GP, Germination Percentage; GE, Germination Energy; SVI, Seedling vigour index; MC, moisture content; chl a, Chlorophyll a; chl b, Chlorophyll b; TSS, Total Dissolved Solids ∗ Corresponding author. E-mail address: senthil@msuniv.ac.in (S. Senthil-Nathan). Biocatalysis and Agricultural Biotechnology 20 (2019) 101190 Available online 04 June 2019 1878-8181/ © 2019 Published by Elsevier Ltd. T