Hydroponic lettuce production in different concentrations and flow rates of nutrient solution

Abstract

The objective of this study was to evaluate the accumulation of fresh weight of hydroponic lettuce in terms of ionic concentrations and flow rates of nutrient solution. This work consisted of three experiments in NFT hydroponic system, conducted between July and September 2006. Lettuce cultivars Lucy Brown, Izabela and Veneza were grown in different ionic concentrations of the 100, 75 and 50% and flow rates of 1.50, 1.00 and 0.75 L min-1. Fresh weight gains were observed for Lucy Brown when grown on 100% of the ion concentration and a flow rate of nutrient solution of 1.0 L min-1. Greater fresh mass was observed for cvs. Izabela and Veneza under the flow rate of 1.5 L min-1. A general analysis of the data allows us to conclude that the application of nutrient solution at a flow rate of 1.5 L min-1, as well as 100% of the ionic concentration is effective to increase the fresh weight of the aerial part of cvs. Lucy Brown, Izabela and Veneza when grown in hydroponics.

Macronutrient deprivation eustress elicits differential secondary metabolites in red and green‐pigmented butterhead lettuce grown in a closed soilless system

“…The above findings are in line with Fallovo et al, 19 who found a significant decrease in yield, leaf-area index, and total dry biomass of lettuce (Lactuca sativa L. var. acephala) grown in floating raft system when NS EC decreased from 2.0 to 0.3 dS m −1 , and with Genuncio et al, 20 who found a significant decrease in lettuce fresh weight when the NS EC decreased from 1.8 to 0.92 dS m −1 . On the other hand, Vernieri et al 31 did not observe a decrease in rocket leaf area when NS was decreased fourfold nor did Chen et al 18 observe a decrease in lettuce shoot fresh weight when NPK levels were reduced a hundredfold.…”

“…Previous studies have demonstrated the effect of reduced nutrient solution levels on yield and particular quality traits of greenhouse leafy vegetables, including lettuce. Certain studies in controlled environments focused on nitrogen levels only, such as Quadir et al .…”

“…Previous studies [17][18][19][20] have demonstrated the effect of reduced nutrient solution levels on yield and particular quality traits of greenhouse leafy vegetables, including lettuce. Certain studies in controlled environments focused on nitrogen levels only, such as Quadir et al 21 and Becker et al, 22 or on nitrogen and phosphorus levels, such as Galieni et al 23 Nevertheless, nothing is known about the interaction between macronutrient deprivation, in the form of reduced macronutrient levels in the nutrient solution, and cultivar, in respect to lettuce PSM profiles.…”

Levels of nitrate, pigments and thermographic analysis of lettuce under different temperatures of nutrient solution

“…This behavior is due to the increase of nutrient solution temperature, which results in increased electrical conductivity thereof. A higher electrical conductivity favors increased nitrate content in lettuce leaves, because the conductivity of the nutritive solution does not only influence the absorption of water, but also the absorption of nutrients, both of which are closely linked (Steidle et al, 2005;Genuncio et al, 2012;Cometti et al, 2013). Tr -Root temperature, Ts -Stem temperature, Tm -Temperature of the middle of the plant, Tex -Temperature of the extremity of the plant.…”

Nitrogen efficiency in hydroponic chicory

“…Some of these advantages are allowing cultivation in small areas, reduction of the crop cycle and production throughout the year, achieving the best prices and reducing the consumption of water, of agricultural inputs and manual labor (Paulus, Dourado Neto, and Paulus 2012;Santos et al 2013). Moreover, this system allows climatic conditions to be controlled and nutrients with appropriate concentrations to be provided for the growth and development of plants, increasing the productivity and quality of the final product (L opez-Pozos et al 2011;Genuncio et al 2012).…”