Impact of a Sargassum spp. Ferment on Agronomic Attributes on Jalapeño Pepper Seedlings Subjected to Salinity

Abstract

Agriculture faces challenges due to climate change, such as water scarcity, soil degradation, and salinity, the latter exacerbated by the excessive use of fertilizers. Salinity induces abiotic stress in plants, altering their metabolism and af fecting their development. In the search for alternatives to mitigate plant stress, biostimulants have emerged as a tool to improve crop yield and quality under both optimal and stressful conditions. Currently, the brown macroalga Sargassum spp. (sargazo) has experienced massive influxes in tropical and subtropical regions, the accumulation of which impacts marine ecosystems, coastal communities, and local economic activities. However, Sargassum represents a potential alternative in agriculture as a biostimulant  due  to  its  content  of  bioactive compounds. The objective of this  study was to evaluate the ef fect of foliar and drench applications of a liquid ferment derived from Sargassum spp. on the agronomic attributes of jalapeño pepper seedlings subjected to saline stress, with 100 mM NaCl incorporated into the nutrient solution. Drench treatments, particularly at a concentration of 2.5% (FD-2.5%), significantly improved these attributes. The FD-2.5% treatment increased stem height (15%) and diameter (13%), as well as fresh shoot biomass and dry root biomass by 12% and 26%, respectively, compared with the saline control. Therefore, drench application of the liquid ferment derived from Sargassum spp. may represent an alternative to promote the growth of jalapeño pepper seedlings under saline stress.