Lettuce Varieties Research Articles

The Effect of LED Light Spectra on the Growth, Yield and Nutritional Value of Red and Green Lettuce (Lactuca sativa).

Controlled Environment Agriculture (CEA) is a method of increasing crop productivity per unit area of cultivated land by extending crop production into the vertical dimension and enabling year-round production. Light emitting diodes (LED) are frequently used as the source of light energy in CEA systems and light is commonly the limiting factor for production under CEA conditions. In the current study, the impact of different spectra was compared with the use of white LED light. The various spectra were white; white supplemented with ultraviolet b for a week before harvest; three combinations of red/blue lights (red 660 nm with blue 450 nm at 1:1 ratio; red 660 nm with blue 435 nm 1:1 ratio; red 660 nm with blue at mix of 450 nm and 435 nm 1:1 ratio); and red/blue supplemented with green and far red (B/R/G/FR, ratio: 1:1:0.07:0.64). The growth, yield, physiological and chemical profiles of two varieties of lettuce, Carmoli (red) and Locarno (green), responded differently to the various light treatments. However, white (control) appeared to perform the best overall. The B/R/G/FR promoted the growth and yield parameters in both varieties of lettuce but also increased the level of stem elongation (bolting), which impacted the quality of grown plants. There was no clear relationship between the various physiological parameters measured and final marketable yield in either variety. Various chemical traits, including vitamin C content, total phenol content, soluble sugar and total soluble solid contents responded differently to the light treatments, where each targeted chemical was promoted by a specific light spectrum. This highlights the importance of designing the light spectra in accordance with the intended outcomes. The current study has value in the field of commercial vertical farming of lettuce under CEA conditions.

The Presence of Potentially Pathogenic Protozoa in Lettuce (Lactuca sativa) Sold in Markets in the Central Peruvian Andes.

Peru is currently one of the world’s leading culinary destinations, whose world-renowned cuisine uses vegetables, mainly lettuce, as frequent ingredients. Vegetable consumption is promoted worldwide as a part of a healthy diet. However, vegetables, more frequently lettuce, have been implicated as a vehicle of infection for several foodborne parasites. This study aimed to determine the presence of potentially pathogenic parasites in lettuce marketed in the Central Andes of Peru. A total of 75 lettuce samples were collected from the two largest wholesale markets and the main open-air market in Jauja province, in the central Peruvian Andes. The province of provenance (coast vs. highlands), lettuce variety (“curly-leaf”, “iceberg”, and “butter”), and type of market were recorded. The samples were microscopically examined for detection of parasitic life forms using standard parasitological methods including direct slide smear, Lugol’s iodine staining, and Modified Ziehl−Neelsen staining. The overall positivity of parasitic contamination in lettuces was 45.3% (CI 95%: 34−56.6%). Cryptosporidium spp., Isospora belli, Giardia lamblia, Balantidium coli, and Entamoeba spp. were detected in twenty-six (34.7%), six (8%), four (5.3%), two (2.7%), and two (2.7%) lettuces, respectively. I. belli was found in a significantly (p < 0.01) lower proportion in the “butter” variety, and significantly (p < 0.05) higher contamination with G. lamblia was found in lettuce sold at the open-air market. B. coli, G. lamblia, and E. histolytica/E. dispar/E. moshkovskii were detected only in lettuce from the highlands (Tarma province). This study provides important data for health authorities to develop food safety programs. This information is also of interest to the international community because of the increased visibility that Peru has gained as a tourist destination.

Retrospective Evaluation of an Integrated Molecular-Epidemiological Approach to Cyclosporiasis Outbreak Investigations - United States, 2021.

Cyclosporiasis results from an infection of the small intestine by Cyclospora parasites after ingestion of contaminated food or water, often leading to gastrointestinal distress. Recent developments in temporally linking genetically related Cyclospora isolates demonstrated effectiveness in supporting epidemiological investigations. We used 'temporal-genetic clusters' (TGCs) to investigate reported cyclosporiasis cases in the United States during the 2021 peak-period (1 May - 31 August 2021). Our approach split 655 genotyped isolates into 55 genetic clusters and 31 TGCs. We linked two large multi-state epidemiological clusters (Epidemiologic Cluster 1 [n=136 cases, 54 genotyped] and Epidemiologic Cluster 2 [n=42 cases, 15 genotyped]) to consumption of lettuce varieties; however, product traceback did not identify a specific product for either cluster due to the lack of detailed product information. To evaluate the utility of TGCs, we performed a retrospective case study comparing investigation outcomes of outbreaks first detected using epidemiological methods with those of the same outbreaks had TGCs been used to first detect them. Our study results indicate that adjustments to routine epidemiological approaches could link additional cases to epidemiological clusters of cyclosporiasis. Overall, we show that CDC's integrated genotyping and epidemiological investigations provide valuable insights into cyclosporiasis outbreaks in the United States.

Growth, development and yield of lettuce varieties under the action of bio-preparations

Growth, development and yield of lettuce varieties under the action of bio-preparations

Роль спектральных характеристик источников излучения в формировании урожая салата при выращивании методом гидропоники

Growing plants indoors in the controlled environment involves the use of LED systems with an adjustable spectrum and intensity with manual or remote control. The aim of the study was to determine the role of different LED emission spectra in growth, development, and yield of lettuce cultivated hydroponically to develop requirements for the LED irradiator design. Studies were carried out in a growth chamber with periodic flooding hydroponics when irradiating lettuce plants of Kuk, Afitsion, and Khrizolit varieties under multispectral irradiators. The first irradiator has a radiation spectrum coinciding with the spectral distribution function of relative photosynthetic activity of solar radiation (control). The radiation of the second one coincides with the function of the spectral sensitivity of plants according to K.J. McCree. The third irradiator has an adjustable spectrum by three control channels for three parts of the spectrum coinciding with chlorophyll synthesis functions. It was found that the response of different lettuce varieties to the spectral composition of irradiation is specific. The maximum yield of the Kuk variety (4.45 kg/m2 ) was obtained under the first irradiator, that of lettuce Afitsion (4.7 kg/m2 ) and Khrizolit (6.55 kg/m2 ) - under the second one. Based on the results obtained the authors made requirements and designed an LED irradiator, which combines all the advantages of LED and digital technologies and provides for the implementation of the required radiation functions for laboratory research and in-vitro plant cultivation. It is noted that the LED module of the irradiator should include LEDs of violet, blue, red, dark red, and far red radiation, as well as LEDs of warm and cool white light colours.

Evaluation of Predrying Steps, Cadmium, and Pesticide Residues on Dried Powders from Romaine Lettuce Outer and Heart Leaves

Romaine lettuce (Lactuca sativa var. longifolia) outer leaves are discarded in fields during harvest and present a prime upcycling opportunity. Although Romaine lettuce is abundant in healthy nutrients, it may contain trace amounts of heavy metals, mainly cadmium (Cd), and pesticides that could lead to acute poisoning. Physical attributes, total soluble phenolics, antioxidant capacity, Cd, and pesticides in powders with different predrying treatments for hearts and outer leaves of two varieties of Romaine lettuce from farms with different Cd content in soils were quantified. Lettuce powders from the Valencia variety had a higher greenish color and true density than the Duquesne variety. Heart leaves from Valencia variety presented higher total soluble phenolics. However, outer leaves from Valencia and Duquesne varieties presented similar levels of total soluble phenolics. Valencia outer and heart leaves presented higher antioxidant capacity. Infrared dry blanching resulted in lower color parameters, total soluble phenolics, and antioxidant capacity, evidencing thermal degradation during this predrying step. Cd concentrations were 10 times higher in the soil where Duquesne Romaine lettuce variety was grown. Accordingly, Duquesne had significantly higher levels of Cd in outer or heart leaves. Outer leaves had higher levels of Cd compared to heart leaves. No differences in pesticides were found in lettuce from both harvesting fields. It is possible to obtain edible powders from Romaine lettuce outer leaves from low-Cd soils and controlled pesticide management, and it may be an alternative way to reduce nitrogen leaching in agricultural soils.

Varieties of Lettuce Forming Distinct Microbial Communities Inhabiting Roots and Rhizospheres with Various Responses to Osmotic Stress

A plant microbiome is an important factor in plant growth, stress resistance, health status, and consumer quality and safety. The rhizosphere microbiome evolves in a negotiation between microbial communities that inhabit soil and plant root tissue. In this study, the rhizosphere and root internal tissue microbiome of six varieties of lettuce were analyzed in normal conditions and under salinity stress. The metabarcoding analysis used 16S rRNA gene and ITS2 region sequencing. The microbiomes of root samples were significantly less diverse with different members of the community compared to those of the rhizosphere. A significant effect of lettuce variety was found on the diversity index for bacteria and fungi. Varieties formed very different communities of bacteria in roots. Pseudomonas, Herbaspirillum, Mycobacterium, potentially pathogenic Enterobacter, and other genera were more prevalent in certain varieties. Salinity stress had a significant negative impact on bacterial diversity and community composition, whereas the diversity of fungi has not changed significantly, and the fungal community has changed less than the bacterial one. Changes were more evident in varieties that were more resistant to salinity stress than in sensitive varieties.

Classification and Prediction by Pigment Content in Lettuce (Lactuca sativa L.) Varieties Using Machine Learning and ATR-FTIR Spectroscopy.

Green or purple lettuce varieties produce many secondary metabolites, such as chlorophylls, carotenoids, anthocyanins, flavonoids, and phenolic compounds, which is an emergent search in the field of biomolecule research. The main objective of this study was to use multivariate and machine learning algorithms on Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR)-based spectra to classify, predict, and categorize chemometric attributes. The cluster heatmap showed the highest efficiency in grouping similar lettuce varieties based on pigment profiles. The relationship among pigments was more significant than the absolute contents. Other results allow classification based on ATR-FTIR fingerprints of inflections associated with structural and chemical components present in lettuce, obtaining high accuracy and precision (>97%) by using principal component analysis and discriminant analysis (PCA-LDA)-associated linear LDA and SVM machine learning algorithms. In addition, PLSR models were capable of predicting Chla, Chlb, Chla+b, Car, AnC, Flv, and Phe contents, with R2P and RPDP values considered very good (0.81−0.88) for Car, Anc, and Flv and excellent (0.91−0.93) for Phe. According to the RPDP metric, the models were considered excellent (>2.10) for all variables estimated. Thus, this research shows the potential of machine learning solutions for ATR-FTIR spectroscopy analysis to classify, estimate, and characterize the biomolecules associated with secondary metabolites in lettuce.

Effect of Nutrients Composition on The Growth Parameters of Two Lettuce Varieties in Hydroponic Culture With Solid Growing Media

Effect of Nutrients Composition on The Growth Parameters of Two Lettuce Varieties in Hydroponic Culture With Solid Growing Media

Transcriptome and Metabolome Analysis Revealed That Exogenous Spermidine-Modulated Flavone Enhances the Heat Tolerance of Lettuce.

Lettuce is sensitive to high temperature, and exogenous spermidine can improve heat tolerance in lettuce, but its intrinsic mechanism is still unclear. We analyzed the effects of exogenous spermidine on the leaf physiological metabolism, transcriptome and metabolome of lettuce seedlings under high-temperature stress using the heat-sensitive lettuce variety 'Beisansheng No. 3' as the material. The results showed that exogenous spermidine increased the total fresh weight, total dry weight, root length, chlorophyll content and total flavonoid content, increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and decreased malondialdehyde (MDA) content in lettuce under high temperature stress. Transcriptome and metabolome analyses revealed 818 differentially expressed genes (DEGs) and 393 metabolites between water spray and spermidine spray treatments under high temperature stress, and 75 genes from 13 transcription factors (TF) families were included in the DEGs. The Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis of DEG contains pathways for plant-pathogen interactions, photosynthesis-antennal proteins, mitogen-activated protein kinase (MAPK) signaling pathway and flavonoid biosynthesis. A total of 19 genes related to flavonoid synthesis were detected. Most of these 19 DEGs were down-regulated under high temperature stress and up-regulated after spermidine application, which may be responsible for the increase in total flavonoid content. We provide a possible source and conjecture for exploring the mechanism of exogenous spermidine-mediated heat tolerance in lettuce.

Influence of Pulsed, Scanning and Constant (16- and 24-h) Modes of LED Irradiation on the Physiological, Biochemical and Morphometric Parameters of Lettuce Plants (Lactuca sativa L.) while Cultivated in Vertical Farms

In city farming, when growing green crops, a significant part of the production cost is the cost of electricity for lighting. The physiology, biochemistry, morphology and productivity of plants can be affected by changing irradiation modes and these changes reduce electricity costs. However, the results of studies in the literature are contradictory. In this work, we investigated the effect of impulse (frequency 1000 Hz and duty cycle 67%), scanning (the principle of running lights) and constant 16 h and 24 h modes of operation of white light LED irradiators on the physiological, biochemical and morphometric parameters of lettuce with red and green leaves. The daytime integral of light in all variants remained unchanged ~15.6 mol m−2 day−1. Daily electricity consumption also did not differ significantly. Plants were grown on racks in a climatic chamber up to 35 days of age. For lettuce with red leaves, the most optimal for biomass accumulation and synthesis of anthocyanins was the impulse illumination mode, while for lettuce with green leaves, no statistically significant differences in biomass were observed under different irradiation modes. For red-leaved lettuce, it was found that the highest concentration of carotenoids in the leaf was observed under constant (24 h) and scanning irradiation, which is associated with a more active reaction of the photosynthetic system to prolonged irradiation and increased intensity during scanning irradiation. Also, increased photosynthetic activity was found in both varieties of lettuce at 16 h of operation of LED irradiators, which, however, did not affect their final productivity. The results may be useful for the development of LED illuminators for use in rack growing.

Sıvı Solucan Gübresinin Değişik Marul Çeşitlerinin Kalite Özelliklerine Etkisi

The experiment was conducted in one of the unheated plastic polyethylene (PE) greenhouses of Ege University- Bayındır Vocational Training School -TURKİYE during the winter-early spring of 2019-2020. The goal of the trial was to evaluate the effects of liquid vermicompost (LVC) on Iceberg (Head salad) and Lolo rosso (Lactuca sativa) lettuce in a floating hydroponic system. Two types of growing pools were used as the growing media, one was made of galvanized steel and the other plastic polyethylene. Both pools were covered with a polyethylene at a height of 1 meter from the ground. Lettuce seedlings were transplanted into pools filled with water and a week later Liquid Vermicompost (LVC) and Hoagland Nutrient Solution (HNS) were added to the growing media according to the treatments. The trial was set up in a Randomized Block Design (RBD) with 3 treatments and 3 replications in both of the lettuce varieties. 1. Application: HNS +LVC; 2. Application (HNS); 3. Application (LVC). Lettuce leaves were harvested 84 days after the LVC and HNS applications and prepared for analysis. In this research, in order to determine the impact of liquid vermicompost on Iceberg and Lolo rosso lettuce varieties total yield, marketable yield, the number of leaves discarded, root length and root weights were determined after harvested plants. In both of the lettuce varieties, results indicated that the highest marketable yields were obtained in the first treatment (HNS+LVC). The highest root length and root weight were also determined in the first treatment. It can be concluded that adding liquid vermicompost (100 ml / 100 L water ratio) to the growing solutions of Iceberg (Head lettuce) and Lolo rosso (Lactuca sativa) lettuce varieties, high performances can be obtained.

The Impact of CO2 Enrichment on Biomass, Carotenoids, Xanthophyll, and Mineral Content of Lettuce (Lactuca sativa L.)

Carbon dioxide (CO2) concentrations affect the growth rate of plants by increasing photosynthesis. Increasing CO2 in controlled environment agriculture (CEA) provides a means to boost yield or decrease daily light integral (DLI) requirements, potentially increasing profitability of growing operations. However, increases in carbon dioxide concentrations are often correlated with decreased nutritional content of crops. The objectives of this experiment were to quantify the effects of carbon dioxide on the growth, morphology, and nutritional content of two lettuce varieties, ‘Rex’ and ‘Rouxai’ under four CO2 concentrations. Applied CO2 treatments were 400, 800, 1200, and 1600 ppm in controlled environment chambers with identical DLI. Lettuce was germinated for eight days in a greenhouse, then transplanted into potting mix and placed in a growth chamber illuminated by fluorescent lights. After 21 days, lettuce was destructively harvested, and fresh weight and plant volume were measured. Anthocyanins, xanthophylls, chlorophyll, and mineral concentration were measured. The lettuce fresh and dry weight increased with increasing CO2 concentrations, with the greatest increases observed between 400 and 800 ppm, and diminishing increases as CO2 concentration further increased to 1200 and 1600 ppm. Violaxanthin was observed to decrease in ‘Rouxai’ with increasing CO2 concentration. Largely, no significant differences were observed in lutein, anthocyanins, and mineral content. Overall, increasing concentrations of carbon dioxide can significantly increase the yield for lettuce in controlled environments, while not significantly reducing many of the nutritional components.

LettuceGDB: The community database for lettuce genetics and omics

As a globally popular leafy vegetable and a representative plant of the Asteraceae family, lettuce has great economic and academic significance. In the last decade, high-throughput sequencing, phenotyping, and other multi-omics data in lettuce have accumulated on a large scale, thus increasing the demand for an integrative lettuce database. Here, we report the establishment of a comprehensive lettuce database, LettuceGDB (https://www.lettucegdb.com/). As an omics data hub, the current LettuceGDB includes two reference genomes with detailed annotations; re-sequencing data from over 1000 lettuce varieties; a collection of more than 1300 worldwide germplasms and millions of accompanying phenotypic records obtained with manual and cutting-edge phenomics technologies; re-analyses of 256 RNA sequencing datasets; a complete miRNAome; extensive metabolite information for representative varieties and wild relatives; epigenetic data on the genome-wide chromatin accessibility landscape; and various lettuce research papers published in the last decade. Five hierarchically accessible functions (Genome, Genotype, Germplasm, Phenotype, and O-Omics) have been developed with a user-friendly interface to enable convenient data access. Eight built-in tools (Assembly Converter, Search Gene, BLAST, JBrowse, Primer Design, Gene Annotation, Tissue Expression, Literature, and Data) are available for data downloading and browsing, functional gene exploration, and experimental practice. A community forum is also available for information sharing, and a summary of current research progress on different aspects of lettuce is included. We believe that LettuceGDB can be a comprehensive functional database amenable to data mining and database-driven exploration, useful for both scientific research and lettuce breeding.

Agronomic evaluation of different lettuce (Lactuca sativa L.) varieties under unheated plastic tunnel

Among the leafy vegetables, lettuce (Lactuca sativa L.) is the most widely grown species in the world. Wide ranges of physical properties of the products are used to assess the degree of maturity. In this study, different lettuce varieties were grown under an unheated plastic tunnel in springtime. We evaluated the agronomic properties of different lettuce varieties, evaluated the condition of the plants, and determined the bioactive substances. Larger head weight can be achieved by the ‘King of May’ butterhead (259.31 g) and ‘Great Lakes 659’crisphead (220.40 g) genotypes. A very strong correlation (r = 0.995) was observed between the lettuce head index, and leaf index and both had a strong positive correlation (r = 0.828 and 0.760) with NDVI. The highest SPAD values were measured for cos lettuce ‘Romaine lettuce’ (44.01) and iceberg lettuce ‘Great Lakes 659’ (42.71). However, these genotypes showed the highest (9.52%; 8.74%) dry matter content, too. The red leaf variety 'Lollo Rosso' had the highest total polyphenol content (181.53 GAE/100 g FW). Among the evaluated properties, iceberg lettuce showed favorable morphology, plant condition, and good dry matter content. In addition, between the loose-leaf lettuces, the red leaf lollo type was outstanding with bioactive content.

Effects of Supplemental UV-A LEDs on the Nutritional Quality of Lettuce: Accumulation of Protein and Other Essential Nutrients

Light plays an important role in influencing the nutritional quality of food crops, especially with regard to the health-promoting phytochemicals. However, its role in affecting the nutritional quality with regard to the essential nutrients is not well understood. In this study, the effects of preharvest UV-A treatment on the nutritional quality of lettuce (Lactuca sativa, cv. red-leaf ‘New Red Fire’ and green-leaf ‘Two Star’) in relation to the essential nutrients and health-promoting phytochemicals were explored. Lettuce plants were grown in a growth chamber and were subjected to supplemental UV-A LEDs (peak wavelength 375 nm) for a brief period (3–6 days) prior to harvest. UV-A LEDs were equipped with lenses to control the light dispersion. Many growth indices such as shoot fresh mass, leaf area, and leaf number were unaffected by supplemental UV-A in both varieties while shoot dry mass decreased in response to a 6-day UV-A treatment compared to the control. Leaf chlorophyll and carotenoid concentrations increased significantly in green-leaf lettuce after 3 or 6 days of UV-A treatment, but only after 3 days of UV-A treatment in red-leaf lettuce compared to the control. Leaf protein concentration increased significantly in both lettuce varieties along with a number of essential nutrients such as phosphorus, potassium, calcium, manganese, and sulfur in response to supplemental UV-A. Supplemental UV-A increased the accumulation of protein by approximately 48% in green-leaf lettuce and 31% in red-leaf lettuce compared to the control plants. Moreover, in addition to the above essential nutrients, green-leaf lettuce accumulated higher amounts of magnesium, copper, and zinc compared to the control plants, indicating that green-leaf lettuce was more responsive to preharvest supplemental UV-A treatment than red-leaf lettuce. However, the accumulation of total phenolic compounds and flavonoids in both varieties was lower under supplemental UV-A. Furthermore, the use of LED lenses did not have a consistent impact on most of the plant responses studied. Overall, the results indicate that a brief preharvest exposure of both red- and green-leaf lettuce varieties to UV-A increased their nutritional quality by enhancing the accumulation of protein and other major essential nutrients.

Lettuce growth promoted by artificial lighting using light-emitting diodes (LED)

Understanding how the use of light-emitting diodes (LED) in artificial lighting affects plant growth is of considerable interest to Science because the application of specific light wavelengths to crops can enhance agricultural production. Therefore, the influence of LED lamps in the photosynthetically active spectrum (blue and red light) on the growth of lettuce (Lactuca Sativa) was evaluated. A factorial design was used to test 4 combinations of LED lighting (5:1; 3:1; 1:1 and 6:3) and 2 lettuce varieties (butterhead and crisphead). The plants were grown in pots in a controlled environment with a 12h-photoperiod, for 21 days. Leaf number (LN), leaf area (LA) and leaf fresh mass (LFM) were determined along with gas exchange variables (A: net photosynthesis; Ci: CO2internal concentration; and WUEi: instantaneous water use efficiency. Growth of lettuce plants was greatest in the source of variation of LED lighting with the combination 5:1, as well as the greatest photosynthetic efficiency. The crisphead lettuce was superior to the butterhead lettuce in all analyzed variables, which suggests a better adaptation to the treatments applied.

Estimation of Greenhouse Lettuce Growth Indices Based on a Two-Stage CNN Using RGB-D Images.

Growth indices can quantify crop productivity and establish optimal environmental, nutritional, and irrigation control strategies. A convolutional neural network (CNN)-based model is presented for estimating various growth indices (i.e., fresh weight, dry weight, height, leaf area, and diameter) of four varieties of greenhouse lettuce using red, green, blue, and depth (RGB-D) data obtained using a stereo camera. Data from an online autonomous greenhouse challenge (Wageningen University, June 2021) were employed in this study. The data were collected using an Intel RealSense D415 camera. The developed model has a two-stage CNN architecture based on ResNet50V2 layers. The developed model provided coefficients of determination from 0.88 to 0.95, with normalized root mean square errors of 6.09%, 6.30%, 7.65%, 7.92%, and 5.62% for fresh weight, dry weight, height, diameter, and leaf area, respectively, on unknown lettuce images. Using red, green, blue (RGB) and depth data employed in the CNN improved the determination accuracy for all five lettuce growth indices due to the ability of the stereo camera to extract height information on lettuce. The average time for processing each lettuce image using the developed CNN model run on a Jetson SUB mini-PC with a Jetson Xavier NX was 0.83 s, indicating the potential for the model in fast real-time sensing of lettuce growth indices.

Agronomic efficiency of the inoculant FT10 (Trichoderma asperelloides) on four lettuce varieties

The present study aimed to evaluate the agronomic efficiency of FT10 (Trichoderma asperelloides) on lettuce varieties development and productivity throughout the year. Four greenhouse experiments were carried out to verify the effect of three doses of the bio-product on plant growth and yield on loose-leaf, butterhead, iceberg and salad bowl cultivars. A randomized block design was used, with six replications. The treatments were: 1) control, 2) 30.0 x 1012 CFU.ha-1 of the commercial inoculant ICB Nutrisolo ® Trichoderma, 3) 5.0 x 1011 CFU.ha-1 of FT10 inoculant, 4) 10.0 x 1011 CFU.ha-1 of FT10, and 5) 15.0 x 1011 CFU.ha-1 of FT10. Plant dry weight and yield were evaluated 42 DAT. The data obtained were compared with Duncan's test. Significant increases in yield in up to 21% for loose-leaf and 16% for butterhead were observed with the dose of 15.0 x 1011 CFU.ha-1 and 22% for iceberg and salad bowl with the dose of 10.0 x 1011 CFU.ha-1 of FT10. It can be concluded that FT10 has the potential to promote plant growth and increase the productivity of lettuce cultivars if applied the appropriate dose of the product.&#x0D;

Effect of Different Levels of Nutrients on Plant Growth, Yield and Quality of Lettuce (Lactuca sativa) in NFT (Nutrient Film Technique) Vertical System of Hydroponics under Shade Net Condition

The present experiment was carried out under the Shade net, Research Field, Department of Horticulture, SHUATS, Prayagraj during the month of November 2021 to February 2022. Experiment was laid out in Randomized Block Design (RBD), with eight treatments, replicated thrice with nutrient field technique hydroponics system and lettuce variety Grand Rapids. The treatments were T1 (NPK 2.8ml/Plant), T2 (NPK 4.2ml/Plant), T3 (NPK 5.71ml/Plant), T4 (NPK 7.14ml/Plant), T5 (NPK 8.57ml/Plant), T6 (NPK 10ml/Plant), T7 (NPK 11.43ml/Plant) and T8 (NPK12.86ml/Plant). From the observations T5 was found to be the best relating to growth and yield parameters followed by T6 and T7. In gross return, net return and B.C maximum values were also recorded in T5.