Effect of <italic>Kappaphycus alvarezii</italic> seaweed liquid extract on growth, yield and chemical constituents of Geranium (<italic>Pelargonium graveolens</italic> l’ Herit. ex Aiton)

AbstractThe application of seaweed-based fertilizers is an important renewable resource and gaining considerable attention in the present scenario of agriculture and horticulture as organic nutrient input and growth promoters. The present study was conducted to examine the effect of seaweed liquid extract on growth, yield, and chemical constituents of the important aromatic plant geranium. The experiments were conducted in the CSIR-CIMAP, Research Center, Bengaluru (Karnataka, India) during the Rabi season of 2018–2019 and 2019–2020. The results of pooled data over two years revealed that application of <italic>Kappaphycus alvarezii</italic> seaweed liquid extract (KSWE) along with RDF at a concentration of 15% significantly improved the plant height (71.37 ± 0.69 cm), plant canopy (68.24 ± 1.60 cm), herb yield (42.71 ± 2.45 t ha−1year−1) and oil recovery (0.36 ± 0.02%) as compared over RDF. An account of 23.14% and 23.87% increase in herbage and essential oil yield was recorded over RDF. The functional relationship between herb and oil yield of geranium with different concentrations of seaweed extract applied at different crop stages was strongly correlated (<italic>r</italic>2=0.97 and <italic>r</italic>2=0.91, respectively). The chemical profile of essential oil reveals that higher amounts of linalool (7.5%) isomenthone (6.65%), geranial (1.29%), geranyl formate (3.81%), and the highest citronellol to geraniol (C:G ratio) ratio of 2.14 was noticed in the treatment which receives 15% KSWE along with RDF. The study clearly exhibits the notable benefits in the performance of geranium with the application of 15% of aqueous seaweed extract from <italic>Kappaphycus alvarezii</italic> both in quantitative and qualitative terms. [ABSTRACT FROM AUTHOR]