Periodicity of Exposure of Hydroponic Lettuce Plants to Nutrient Solution1

Abstract

A balanced periodicity of the nutrient solution flow is essential for better agronomic performances and low production costs in hydroponic systems. Thus, the objective of this work was to evaluate the effect of periodicity of exposure of lettuce plants to the nutrient solution in an NFT hydroponic system on the production, nutrition, and profitability of this crop. The experiment was conducted in a randomized block design with five replications. The treatments consisted of four periodicities of exposure of lettuce plants to the nutrient solution, consisting of intervals of 60, 30, and 15 minutes between pumping periods of 15 minutes; and uninterrupted flow of the nutrient solution. The plants were harvested at 30 days after transplanting, and 15 lettuce plants of each experimental plot were used to determine total fresh weight; root fresh weight; shoot freshweight; and contents of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn in shoots, roots, and in the diagnostic leaf; accumulation of these nutrients in shoots and roots; and nitrate and ammonium contents in plant shoot. The highest production and profitability of lettuce were found using uninterrupted nutrient solution flow, which provided higher shoot and root nutrient contents to plants, and resulted in a better nutrient use efficiency.

Inoculation methods of Azospirillum brasilense in lettuce and arugula in the hydroponic system

“…Its consumption and commercial value have increased in recent decades due to its peculiar "slightly spicy and flavorful leaves" (Cantarella et al, 2022). In the current scenario, using the hydroponic system to grow vegetables has enabled yield gains, versatility, precocity, and, most importantly, post-harvest improvements (Dalastra et al, 2020b).…”

Inoculation with Azospirillum brasilense Strains AbV5 and AbV6 Increases Nutrition, Chlorophyll, and Leaf Yield of Hydroponic Lettuce

“…The fresh matter of lettuce is one of the most important traits of freshly marketable vegetables [6]. The current results showed that the shoot fresh and dry matter of hydroponic lettuce improved with increasing doses of A. brasilense when compared with non-inoculated plants (Figure 1A,C).…”

“…Its cultivation in a hydroponic system has obtained more attention for healthy and quality production in a short duration [4], using a nutrient solution and protected environments to promote nutrient use efficiency for Plants 2023, 12, 3107 2 of 15 greater plant growth, nutrient accumulation, and even yield [5]. The higher concentration of nutrients (electrical conductivity) and time of exposure to the nutrient solution can increase water use efficiency, yield, and precocity of hydroponic lettuce [6]. Despite nutrient management, inoculation with plant-growth-promoting bacteria (PGPBs) is one of the sustainable alternatives that could increase nutrient use efficiency and accumulation by plants.…”