Impact of seaweed sap foliar application on growth, yield, and tuber quality of potato (Solanum tuberosum L.)

Field experiments were carried out during winter 2015–2016 and 2016–2017 at research farm of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India to study the growth, productivity, quality, and profitability of potato (cv. Kufri Jyoti) cultivation as influenced by foliar application of different seaweed extracts, i.e., Kappaphycus alvarezii sap (K sap) and Gracilaria edulis sap (G sap). The experiment was laid out in a randomized complete block design comprised of two different concentrations (5% and 10%) of each K sap, G sap, and GA3-free K sap, and a control plot (water spray), with three replications. Foliar feeding with 10% K sap along with recommended dose of fertilizer (200 kg N, 150 kg P, and 150 kg K ha−1) brought about significant enhancement in plant height, being statistically similar with 10% G sap. Similar treatment resulted in maximum tuber bulking rate (17.62 and 18.93 g m−2 day−1 at 50–70 DAP in year 1 and year 2, respectively) and tuber yield (26.37 and 29.77 t ha−1 in year 1 and year 2, respectively), accounting 32.11% and 24.87% yield enhancement over control. Maximum nutrient (N, P, and K) uptake as well as best values of quality traits in terms of ascorbic acid, reducing sugar content, and specific weight of potato tuber was recorded with economically viable treatment having 10% K sap spray. Results suggested that the application of seaweed sap at higher concentration along with the recommended dose of fertilizer was the potential alternative way for better potato production without harming the ecological sustainability.