scholarly journals A Study of the Effectiveness of Hydroponic Growing Variables on Lactuca sativa var. capitata

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Jacob Zajkowski ◽  
Whitney Short
Keyword(s):  
Deep Water ◽  
Lactuca Sativa ◽  
Nutrient Concentration ◽  
Growth Efficiency ◽  
Nutrient Concentrations ◽  
Small Scale ◽  
Controlled Environment ◽  
Water Culture ◽  
Future Studies ◽  
System Variables

Hydroponic growing in controlled environment horticulture has been an increasingly used method of produce production around the world. Its many methods integrate sustainability and growth efficiency through the control of climatic and system variables. This study investigated control variables that would produce and market a more effective lettuce (lactuca sativa. var capitata) crop. Three objectives determined: The comparison between the dimensions of deep water culture systems and the lettuce harvesting length, Consumer and ICP spectrometry recognition of different post-harvest hydroponic nutrient concentration, and the preference of lettuce grown in different hydroponic nutrient concentrations. Through growing trials and consumer tests, it was found that the 14 gallon (102 x 50.8 x 66cm) size deep water culture system also produced lettuce with larger harvest-length; spectrometry recognition of lettuce crops grown in different nutrient levels was effective with 7 of the 12 nutrients elements showing sufficient results of concentration in concentrated lettuce. Consumer identification recognition wasn’t successful with 40% of consumers unable to recognize any nutrient concentration level compared to two other varieties. Representing a diverse market audience, of consumers determined that variety 127 (50% regular concentration) was preferred as significant market influence of purchase. This research will impact future studies in effective small scale hydroponic growing and growers looking to expand knowledge of beneficial growth.

scholarly journals Effect of Bacillus spp. on Lettuce Growth and Root Associated Bacterial Community in a Small-Scale Aquaponics System

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 947
Author(s):  
Nasser Kasozi ◽  
Horst Kaiser ◽  
Brendan Wilhelmi
Keyword(s):  
Water Quality ◽  
Control Systems ◽  
Deep Water ◽  
Bacterial Communities ◽  
Small Scale ◽  
Rrna Gene ◽  
Culture Solution ◽  
Water Culture ◽  
Lettuce Growth ◽  
The Mean

The integration of probiotics in aquaponics systems is a strategy for mitigating environmental impacts and for promoting sustainable agriculture. In order to understand the role of probiotics, we investigated the effect of a commercial probiotic mixture of Bacillus subtilis and B. licheniformis on the growth of lettuce (Lactuca sativa L.) under deep-water culture integrated with Mozambique tilapia (Oreochromis mossambicus). We determined plant growth, water quality parameters, and leaf mineral analysis, and assessed the influence of a probiotic mixture on the microbiota. Bacterial communities were analyzed by high-throughput 16S rRNA gene sequencing. Compared to the control systems, the addition of the probiotic Bacillus significantly increased the concentration of nitrate and phosphate in deep water culture solution, which contributed to improved lettuce growth. In both the growth trials, the Fv/Fm, the mean shoot dry weight, and the mean fresh weight of the harvested shoots from the Bacillus treatment were significantly higher than those observed for the control plants. Higher concentrations of phosphorus, potassium, and zinc in the lettuce leaves were found in systems that received the Bacillus. Although differences were observed at the phylum level, Proteobacteria and Bacteroidetes were predominant in both the Bacillus-treatment and the control systems. At the genus level, however, the communities present in the two types of systems were heterogeneous with Bacillus-treated systems, containing significantly higher numbers of Chryseobacterium, Bacillus, Nitrospira, Polynucleobacter, and Thermomonas. The results indicate that Bacillus supplementation can effectively alleviate nutrient deficiencies, improve water quality, and modify the composition of bacterial communities in aquaponics systems.

Using explanatory crop models to help decision support system in controlled environment agriculture (CEA)

2020 ◽  
Author(s):  
Chiara Amitrano ◽  
Giovanni Battista Chirico ◽  
Youssef Rouphael ◽  
Stefania De Pascale ◽  
Veronica De Micco
Keyword(s):  
Lactuca Sativa ◽  
Environmental Control ◽  
Leaf Temperature ◽  
Environmental Data ◽  
Plant Phenotyping ◽  
Small Scale ◽  
Controlled Environment ◽  
Lactuca Sativa L ◽  
Controlled Environment Agriculture ◽  
Nominal Condition

<p>Lettuce (Lactuca sativa L.) is a popular leafy vegetable, widely grown and consumed throughout the world. Growing Lettuce plants in controlled environment, it is useful to increase the yield and obtain production year-round. In CEA (Controlled Environment Agriculture), computer technology is an integral part in the production and different sensors used to monitor environmental parameters and activate environmental control, are necessary. With the advent of technology, proximal sensors and plant phenotyping (in terms of physiological measurements of plant status) can help farmers in crop management. However, these kinds of tools are often expensive or inaccessible for stakeholders. The application of these tools to small-scale cultivation trials, could provide data for the implementation of mathematical models capable of predicting changes possibly happening during the cultivation. These models could then be applied at larger scales, as extensive farm production and be used to help in the cultivation management.</p><p>In this study, green and red cultivars of Lactuca sativa L. ‘Salanova’ were grown in a growth chamber under controlled environmental condition (T, RH, light intensity and quality) in two trials under different vapour pressure deficit (VPD) : 1) VPD of 0.70 kPa (Low VPD; nominal condition) and 2) VPD of 1.76 (High VPD; off nominal condition). Plants were irrigated to field-capacity and weighted every-day in order to record daily ET; infra-red measurements were carried out to record leaf temperature and pictures were taken to monitor growth during the cultivation. Furthermore, after 23 days, on fully developed leaves, eco-physiological analyses (gas exchange and chlorophyll “a” measurements) were performed to assess the plant physiological behaviour in response to the different environmental conditions. Environmental data, were used as inputs in an energy cascade model (MEC) to predict changes in the plant daily growth, photosynthesis and evapotranspiration. The original model, was implemented with a few variations: leaf temperature (T) was used in place of air T for computing the stomatal conductance (gs) and the model parameters maxCUE and maxQY, were differentiated for the nominal and off-nominal scenarios and for green and red lettuce cultivars. After the validation against experimental data, this model appears to be a promising tool that can be implemented for forecasting variations triggered by anomalies in the environmental control. However, a next step will be to add a few parameters that will consider the intrinsic morpho-physiological variability of plants during leaf development.</p>

Effects of Beer and Lettuce (Lactuca Sativa) Consumption on Antioxidant Status in Healthy Volunteers: A Small-Scale Crossover Trial

2014 ◽  
Vol 10 (3) ◽  
pp. 163-172
Author(s):  
Elena Azzini ◽  
Federica Intorre ◽  
Eugenia Venneria ◽  
Maria Foddai ◽  
Elisabetta Toti ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Lactuca Sativa ◽  
Antioxidant Status ◽  
Crossover Trial ◽  
Small Scale

scholarly journals Isolation and Molecular Characterization of the Romaine Lettuce Phylloplane Mycobiome

2021 ◽  
Vol 7 (4) ◽  
pp. 277
Author(s):  
Danny Haelewaters ◽  
Hector Urbina ◽  
Samuel Brown ◽  
Shannon Newerth-Henson ◽  
M. Catherine Aime
Keyword(s):  
Lactuca Sativa ◽  
New Combinations ◽  
Food Spoilage ◽  
Human Pathogens ◽  
Plant Leaves ◽  
Romaine Lettuce ◽  
Future Studies ◽  
The Core ◽  
American Agriculture

Romaine lettuce (Lactuca sativa) is an important staple of American agriculture. Unlike many vegetables, romaine lettuce is typically consumed raw. Phylloplane microbes occur naturally on plant leaves; consumption of uncooked leaves includes consumption of phylloplane microbes. Despite this fact, the microbes that naturally occur on produce such as romaine lettuce are for the most part uncharacterized. In this study, we conducted culture-based studies of the fungal romaine lettuce phylloplane community from organic and conventionally grown samples. In addition to an enumeration of all such microbes, we define and provide a discussion of the genera that form the “core” romaine lettuce mycobiome, which represent 85.5% of all obtained isolates: Alternaria, Aureobasidium, Cladosporium, Filobasidium, Naganishia, Papiliotrema, Rhodotorula, Sampaiozyma, Sporobolomyces, Symmetrospora and Vishniacozyma. We highlight the need for additional mycological expertise in that 23% of species in these core genera appear to be new to science and resolve some taxonomic issues we encountered during our work with new combinations for Aureobasidiumbupleuri and Curvibasidium nothofagi. Finally, our work lays the ground for future studies that seek to understand the effect these communities may have on preventing or facilitating establishment of exogenous microbes, such as food spoilage microbes and plant or human pathogens.

scholarly journals Nutrient behavior in a highly-eutrophicated tropical estuarine system

2016 ◽  
Vol 28 (0) ◽  
Author(s):  
Nilva Brandini ◽  
◽  
Ana Paula de Castro Rodrigues ◽  
Ilene Matanó Abreu ◽  
Luiz Carlos Cotovicz Junior ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chlorophyll A ◽  
River Mouth ◽  
Nutrient Concentrations ◽  
Phytoplankton Production ◽  
Small Scale ◽  
Estuarine System ◽  
Temperature Conductivity ◽  
Se Brazil ◽  
Iguaçu River

Abstract Aim: There are few studies dealing with the biogeochemical processes occurring in small estuaries receiving high sewage loading in tropical regions. The aim of this investigation was to characterize the biogeochemical behavior of nutrients in superficial waters collected at the Iguaçu estuarine system, during specific conditions (neap tide), located at the inner sector of a heavily eutrophicated embayment (Guanabara Bay, SE Brazil). Methods Physical and chemical variables were measured in situ (pH, temperature, conductivity, salinity, total dissolved solids, transparency, dissolved oxygen), whereas suspended particulate matter, chlorophyll a, phaepigments and nutrients (carbon, nitrogen and phosphorus forms) were measured in laboratory across the mesohaline estuarine gradient. Results The Iguaçu River mouth is in a high stage of eutrophication, considering nutrient concentrations, chlorophyll a and transparency of water column. Results indicate a transition from heterotrophic conditions to autotrophic conditions, since the nutrients concentrations showed a decreasing pattern along the saline gradient, while the chlorophyll an increased over the transects. The pH values and chlorophyll : phaeopigments ratios are significantly related to the amount and quality of organic matter contents, especially at transects under strong marine influence. More than 95% of the dissolved and total nitrogen concentrations are represented by NH4+ contributions, which are related to the ammonification of organic matter contents in this region, indicating the existence of untreated sewage loads in this area. Conclusion In this study, the Iguaçu River seemed to contribute with high inputs of nutrients that support important phytoplankton production at the inner regions of the bay related to the CO2 sink and autotrophic metabolism, showing the importance of verifying the biogeochemical behaviors of nutrients in estuarine areas, even in small scale.

scholarly journals RESPON PERTUMBUHAN TANAMAN SELADA (Lactuca Sativa L) TERHADAP VOLUME AIR DAN KONSENTRASI LARUTAN NUTRISI GOOD-PLANT SECARA HIDROPONIK

2019 ◽  
Vol 2 (2) ◽  
pp. 43-51
Author(s):  
Nuryulsen Safridar, Sri Handayani
Keyword(s):  
Plant Height ◽  
Lactuca Sativa ◽  
Leaf Age ◽  
Treatment Plant ◽  
Leaf Length ◽  
Plant Nutrients ◽  
Leaf Number ◽  
Water Volume ◽  
Nutrient Concentrations ◽  
Lactuca Sativa L

This study aims to determine the volume of water and the concentration of the nutrient solution and the right good plant to plant growth of lettuce (lactuca sativa L). This research has been carried out in the garden experiment Jabal Ghafur Faculty of Agriculture, University of Sigli. Runs from February to April 2017. This study used a raft floating hydroponics system. Research using completely randomized design (CRD) factorial pattern that is factor of the volume of water and nutrient concentration factor of good-plant. Treatment of the water volume (V) consists of three levels ie (V1) 4 liters of water, (V2) 8 liters of water and (V3) 12 liters of water. Good treatment-plant nutrient concentrations (N) consists of three levels ie (N1) 600 ppm (N2) of 800 ppm and (N3) 1000 ppm, with three replications so overall deplore 27 experimental unit. The volume of water very significant effect on plant height and leaf length aged 10, 20 and 30 days after planting, leaf number aged 20 and 30 days after planting, heavy wet stover age 30 HST, significantly affect the amount of leaf age 10 HST. Good-plant nutrients very significant effect on plant height ages of 20 and 30 days after planting, leaf number and length of leaf age 30 HST, significant effect on plant height HST age 10, age 20 HST leaf length, weight of wet age 30 HST stover.  Keywords: lettuce, hydroponics, water volume and concentration of good-plant nutrients

The Contribution of Videogames to Anti-Social Attitudes and Behaviours amongst Youngsters

2011 ◽  
pp. 237-251
Author(s):  
Olga Albuquerque ◽  
Gillian Grace Moreira
Keyword(s):  
Video Games ◽  
Parental Control ◽  
Social Attitudes ◽  
Video Gaming ◽  
Small Scale ◽  
Age Group ◽  
Simulation Games ◽  
Age And Gender ◽  
Future Studies ◽  
And Gender

Using questionnaires and interviews, the video-gaming habits of 136 youngsters, ranging from the ages of 9 to 15 years, were assessed, taking into consideration their age and gender. It was found that many youngsters are playing games which are not appropriate for their age group, and that long hours are spent at computer screens on these games without parental control or supervision. In fact, most parents do not even know what games their children are playing never mind whether they are rated as suitable for their age group. In addition, differences between boys and girls were significant, allowing us to confirm that boys prefer more action-oriented games while girls choose simulation games. Although the small-scale nature of this study does not allow us to generalise its conclusions, its findings are relevant and can point the way for future studies of this type. The centrality of video games in the lives of children and teenagers today is such that these and the practices they engender need to be taken into account when considering the rise of anti-social, aggressive, and at times violent attitudes and behaviours amongst youngsters.

scholarly journals Distinguishing between Deep-Water Sediment Facies: Turbidites, Contourites and Hemipelagites

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 68 ◽  
Author(s):  
Dorrik Stow ◽  
Zeinab Smillie
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Tectonic Setting ◽  
Regional Scale ◽  
Small Scale ◽  
Physical Parameters ◽  
Sedimentary Characteristics ◽  
Natural Systems ◽  
Facies Types ◽  
Water Facies

The distinction between turbidites, contourites and hemipelagites in modern and ancient deep-water systems has long been a matter of controversy. This is partly because the processes themselves show a degree of overlap as part of a continuum, so that the deposit characteristics also overlap. In addition, the three facies types commonly occur within interbedded sequences of continental margin deposits. The nature of these end-member processes and their physical parameters are becoming much better known and are summarised here briefly. Good progress has also been made over the past decade in recognising differences between end-member facies in terms of their sedimentary structures, facies sequences, ichnofacies, sediment textures, composition and microfabric. These characteristics are summarised here in terms of standard facies models and the variations from these models that are typically encountered in natural systems. Nevertheless, it must be acknowledged that clear distinction is not always possible on the basis of sedimentary characteristics alone, and that uncertainties should be highlighted in any interpretation. A three-scale approach to distinction for all deep-water facies types should be attempted wherever possible, including large-scale (oceanographic and tectonic setting), regional-scale (architecture and association) and small-scale (sediment facies) observations.

scholarly journals Optimal Nutrient Concentration Ranges of ‘Hass’ Avocado Cauliflower Stage Inflorescences—Potential Diagnostic Tool to Optimize Tree Nutrient Status and Increase Yield

HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1707-1715 ◽  
Author(s):  
Salvatore Campisi-Pinto ◽  
Yusheng Zheng ◽  
Philippe E. Rolshausen ◽  
David E. Crowley ◽  
Ben Faber ◽  
...  
Keyword(s):  
Nutrient Concentration ◽  
Fruit Set ◽  
Fruit Size ◽  
Nutrient Status ◽  
Persea Americana ◽  
Nutrient Concentrations ◽  
Full Bloom ◽  
Nutrient Analysis ◽  
Tree Phenology ◽  
Hass Avocado

Optimizing ‘Hass’ avocado (Persea americana Mill.) tree nutrient status is essential for maximizing productivity. Leaf nutrient analysis is used to guide avocado fertilization to maintain tree nutrition. The goal of this research was to identify a ‘Hass’ avocado tissue with nutrient concentrations predictive of yields greater than 40 kg of fruit per tree. This threshold was specified to assist the California avocado industry to increase yields to ≈11,200 kg·ha−1. Nutrient concentrations of cauliflower stage inflorescences (CSI) collected in March proved better predictors of yield than inflorescences collected at full bloom (FBI) in April, fruit pedicels (FP) collected at five different stages of avocado tree phenology from the end of fruit set in June through April the following spring when mature fruit enter a second period of exponential growth, or 6-month-old spring flush leaves (LF) from nonbearing vegetative shoots collected in September (California avocado industry standard). For CSI tissue, concentrations of seven nutrients, nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), sulfur (S), zinc (Zn), and copper (Cu) were predictive of trees producing greater than 40 kg of fruit annually. Conditional quantile sampling and frequency analysis were used to identify optimum nutrient concentration ranges (ONCR) for each nutrient. Optimum ratios between nutrient concentrations and yields greater than 40 kg per tree were also derived. The high nutrient concentrations characterizing CSI tissue suggest current fertilization practices (timing or amounts) might be causing nutrient imbalances at this stage of avocado tree phenology that are limiting productivity, a possibility that warrants further investigation. Because CSI samples can be collected 4–6 weeks before full bloom, nutritional problems can be addressed before they affect flower retention and fruit set to increase current crop yield, fruit size, and quality. Thus, CSI nutrient analysis warrants further research as a potential supplemental or alternative tool for diagnosing ‘Hass’ avocado tree nutrient status and increasing yield.

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