Influence of Ecklonia maxima Extracts on Growth, Yield, and Postharvest Quality of Hydroponic Leaf Lettuce

Abstract

Ecklonia maxima is a brown algae seaweed largely harvested over the last years and used to produce alginate, animal feed, fertilizers, and plant biostimulants. Their extracts are commercially available in various forms and have been applied to many crops for their growth-promoting effects which may vary according to the treated species and doses applied. The aim of the study was to characterize the effect of adding an Ecklonia maxima commercial extract (Basfoliar Kelp; 0, 1, 2, and 4 mL L−1) to the nutrient solution of a hydroponic floating system on growth, yield, and quality of leaf lettuce at harvest and during cold storage (21 days at 4 °C). The supplementation of the E. maxima extract through the mineral nutrient solutions, especially between 2 and 4 mL L−1, enhanced plant growth and improved the yield and many morphological and physiological traits (biomass accumulation, leaf expansion, stomatal conductance, water use efficiency, nitrogen use efficiency, etc.). Preharvest treatments with E. maxima extract were effective in delaying leaf senescence and extending the shelf-life of fresh-cut leaf lettuce. The delay in leaf decay of treated samples allowed to retain an overall quality over the threshold of marketability for up to 21 d of cold storage, especially using 2 mL L−1 of extract.

Evaluating the Use of Biostimulants for Indoor Hydroponic Lettuce Production

“…1; Tables 2 and 3). In contrast to our findings, Cristofano et al (2021a) and Miceli et al (2021) reported increases in growth and yield of hydroponic lettuce plants treated with hydrolyzed proteins and seaweed extracts, respectively, compared with untreated control plants. However, both studies were conducted in a greenhouse where daily temperatures reached up to 34 to 36 C. Considering that lettuce has an optimal day/night temperature close to 24/19 C (Choi et al, 2000;Seginer et al, 1991), the positive effects found in those studies are plausibly attributed to a heat stress tolerance advantage provided by the biostimulant treatments.…”

The Biostimulant Effect of Hydroalcoholic Extracts of Sargassum spp. in Tomato Seedlings under Salt Stress

“…The results of the present in-vestigation show that the treatments without stress showed a greater stomatal conductance. Similar results were reported by Miceli et al [48], indicating that the use of extracts of Ecklonia maxima in lettuce cultivation increased stomatal conductance at all concentrations (1, 2, and 4 mL L −1 ) compared to the control. The results are because brown algae extracts contain osmolytes such as proline, glycine betaine, and carbohydrates, compounds that allow for osmotic adjustment and that facilitate the absorption of water and nutrients by plants [49][50][51].…”

The Effect of Seaweed (Sargassum sp.) and Plant Extract Combinations on the Growth of Mustard Plant (Brassica juncea L.) Grown in Hydroponic Wick System

“…can be used as liquid organic fertilizer. Research by Miceli et al (2021) showed that Ecklonia maxima is a brown algae seaweed between 2 and 4 ml l −1 , enhanced plant growth and improved the yield and many morphological and physiological traits of lettuce. The results showed that the treatment of organic nutrient solutions could not match the quality of AB mix hydroponic nutrient solutions as hydroponic nutrients for mustard plant cultivation.…”