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Green lettuce is a vegetable crop favored by the people of Indonesia, so the demand is increasing. Demand is increasing, so it must increase lettuce production. One way to increase production is by using appropriate planting media and chicken manure fertilizer to provide nutrients for lettuce. The purpose of the study was to obtain the right composition of the growing medium with manure for the growth and yield of green lettuce. Thel relselarch melthold Factolrial RAK, Factolr 1 was polltry manulrel, P1 = 5 tolns ha-1, P2 = 10 tolns ha-1, P3 = 15 tolns ha-1. Factolr 2 is thel colmpolsitioln olf thel planting,M1 = Solil 100%, M2 = Colcolpelat : Solil = 50% : 50%, M3 = Colcolpelat : Solil = 75% : 25% and M4 = Solil : Colcolpelat = 25% : 75% . Thel data olbtaineld frolm thel olbselrvatiolns welrel analyzeld ulsing thel F telst olf analysis with a lelvell olf 5%. If thel telst relsullts havel a significant elffelct, theln prolceleld with thel BNJ with a lelvell olf 5%. The results showed that the composition of the planting media, namely cocopeat soil: soil = 50%: 50% and dosing 15 tons ha-1 poultry manure fertilizer had the best results on plant height, number of leaves, root length and consumption weight of lettuce plants compared to other treatments. The conclusion that the use of the composition of the planting medium, namely cocopeat soil: soil = 50%: 50% and dosing 15 tons ha-1 poultry manure fertilizer obtained the best results to increase lettuce growth and weight. [ABSTRACT FROM AUTHOR]

It is predicted that the average world temperature will rise by 1.5 °C in the next few decades, which may adversely affect vegetable productivity and global food security. The present study aimed to identify lettuce genotype(s) that are tolerant of heat stress so that they may be good candidates for future breeding programs to develop heatstress-tolerant lettuce cultivars. While using a complete randomized design with three replicates, we evaluated the performance of eight lettuce genotypes using a hydroponic system under non-stress (controlled) and heat stress (high temperature) environmental treatments. The effects of environmental treatments on the morphophysiological and agronomic characteristics of the genotypes were assessed. Ten traits were recorded after harvest, i.e., the number of leaves, plant height, root length, yield, fresh root weight, plant weight, leaf area, leaf width, leaf length, and chlorophyll contents. In general, lettuce genotypes cultivated under heat stress exhibited decreased performance in most traits compared to the non-stress treatment group. The yield of SAL092, SAL093, SAL094, SAL095, SAL096, SAL097, and SAL099 decreased by 65.8%, 66.4%, 65%, 28.2%, 40.6%, 76.3%, and 73.1%, respectively, under heat stress. In contrast, SAL098 grown under non-stress conditions showed higher yield, leaf count, root length, plant weight, and plant height by 0.1%, 15.2%, 0.9%, 4%, and 27%, respectively, compared to non-stress conditions. In addition, during heat stress, every trait exhibited a positive correlation with yield, except leaf width, suggesting that productive attributes are crucial for enhancing yield under high-temperature conditions. SAL095 and SAL098 exhibited effective adaptive mechanisms and may be regarded as potential heat-tolerant genotypes for future breeding programs and developing heat-tolerant cultivars and high yields. [ABSTRACT FROM AUTHOR]

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is known that the magnetic field works to change the chemical and physical properties of water and this is reflected in the properties of soil and plant. An experiment was conducted during 2017 and 2018 seasons at a farm in MitKenana village, Qalyobia, Egypt. The aim was to study the effect of water re-magnetization on the properties of water, soil and Lettuce growth. The experiment was divided into four treatments with three replicates. Normal water treatment and other magnetized water treatments were irrigated with water passed through the magnetic device one, two and three times. EC, pH, anions and cations for both water and soil as well as yield and yield components for Lettuce were measured. Results indicated that, irrigation with magnetized water induced positive significant effect on all studied treatments on water, soil and plant where it improved water and soil properties with increasing plant productivity. The one-time passing magnetic treatment of irrigation water significantly decreased electrical conductivity of the soil, but the effect on pH was moderatein addition to increasing lettuce productivity by 29.1% more than non-magnetic treatment. With multiple magnetic treatments, did not show big differences between treated and untreated treatments. [ABSTRACT FROM AUTHOR]

The main aim of this study was to evaluate the effect of saline water, chemicals and organic fertilizers on lettuce (Lactuca sativa L.) growth, its yield and their antioxidant and soil properties. There were two experiments, one was soil, and another was lettuce growth parameters with anti-oxidant enzyme activities by using split-plot design method. Study findings showed the soil properties, the effect of saline water and rice wastes on some soil characters in the first experiment. And the second experiment findings revealed that the higher effect of overall yield, chlorophyll, NPK content, antioxidant enzymes and proline, higher POX level, increased activity of CAT, SOD level, maximum accumulation of proline and dry weight of head were observed in rice wastes and DAP 400 kg/ha treatment than control. [ABSTRACT FROM AUTHOR]

In sub-Saharan Africa, manure and loam soil are popular growing media substrates. However, their poor physiochemical properties limit their use in growing media. Following a survey of farmers, single species sawdust, mixed species sawdust, and rice husk (RH) were selected and composted with poultry manure. Additionally, the RH was charred for use in soilless media. Objectives were to produce feedstock-specific composts and determine appropriate proportion for using them in containerized systems. Three composts produced were amended with soil in ratios of 1:1, 1:2, and 1:3 (v/v) in an initial experiment. In a second experiment (soilless), the single sawdust and RH compost were each amended with RH biochar in ratios of 1:0, 1:1, 1:2 (v/v) and subjected to half or full pot irrigation. RH compost amended soils gave the highest lettuce yield. In the soilless media, 2:1 ratio (v/v) of biochar to sawdust compost gave the highest yield. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aims: Distribution of selenium (Se) in soils around the world is not identical and many soils are classified as Se-poor soils. Therefore, Se fortification of crops grown on these soils is crucial, where increasing Se intake by human - below toxic threshold - is vital for better health. The recent work aims to investigate the possible use of Se to alleviate the detrimental effects of soil salinity on lettuce and enhance its growth, yield quality and Se enrichment. Methods: Field experiments were conducted during two successive seasons (2016 and 2017) in salt-affected soil (EC 4.49 dS m, pH 8.65) using four concentrations of Se (0, 50, 75 and 100 ppm) by three different application methods. Antioxidant capacity, ion leakage, Se content in plant and soil, yield and vegetative parameters of lettuce were measured. Results: The results showed that Se addition mitigated the detrimental effect of salinity on lettuce growth and its development. Se application (100 ppm) increased also the head weight, leaf area, leaves dry weight and chlorophyll content by 46.4, 66.4, 61.8 and 31.5%, respectively, compared to control plants. Likewise, catalase (CAT) and ascorbate peroxidase (APX) activities increased by 108.8 and 123.6%, respectively, as a result for using 100 ppm of Se. Otherwise, Se (100 ppm) reduced the electrolyte leakage from lettuce leaves by 68.4% against control. The positive effect of Se (100 ppm) on lettuce under salinity was fully verified with data of total yield which increased by 42.1% over control. Foliar application increased Se content in lettuce without exceeding the toxic level and residual Se in soil was the lowest among other treatments. Conclusion: The present work reports that in salt-affected soils spraying lettuce with Se (100 ppm) improves its growth, antioxidant capacity, Se fortification and yield quality. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Between factors which may influence on plant growth are light conditions and chemical composition of atmosphere. The objective of this study was to investigate the effect of ozone treatment (at the stage of seeds and seeds + seedlings, described as O 3 -I and O 3 -II) and light colour (white, blue, and white + blue 50:50) on photosynthesis and yield of lettuce ( Lactuca sativa L. ‘Subyana F 1 ’) grown in a hydroponic system. During the experiments the following conditions were maintained: photoperiod 12 h; temperature 22 °C; relative humidity (RH) 65–70%. LED lamps emitted the following light colours: white, blue and white + blue (50:50) (described as W, B and W + B). For all colours, quantum irradiance was 70 μmol m −2 s −1 . Plants were fertigated with a standard nutrient solution with the following chemical composition (mg dm −3 ): N-NH 4 < 10, N-NO 3 150, P-PO 4 50, K 150, Ca 150, Mg 50, Fe 3.00, Mn 0.5, Zn 0.44, Cu 0.03, B 0.01; pH 5.50, EC 1.8 mS cm −1 . The analysed factors significantly modified photosynthetic activity, growth, yield, chlorophyll content (SPAD measurements) and chemical composition of plants. The highest net photosynthesis rate (P N ) was recorded in plants cultivated with O 3 -I under W + B light, while the lowest was observed for O 3 -II under B light. In the case of O 3 -II a highly significant increase of mean N content in leaves was observed, together with decreases of P, Ca, Mg, Na, Fe and Mn contents in comparison to control plants. An improvement of yield (although not statistically significant) was found in O 3 -I plants, while O 3 -II application caused a decrease of the yield, for B light by about −27.87%, for W −53.74% and for W + B −46.51%. Similar observations were noted for the number of leaves. Moreover, a significant effect of O 3 -I on chlorophyll content was noted, excluding plants cultivated under W light. It seems that ozonization of seeds improves their germination and some other growth and physiological processes, while a second ozonization impairs the condition of plants and has a similar effect as tropospheric ozone in outside conditions. From the practical point of view, it would be interesting to investigate the effect of ozonization and other light colours on different crop species. [ABSTRACT FROM AUTHOR]

This study investigated whether intensive nutrition with sulfur–sulfate (S-SO4) (2, 6, or 9 mM S) of nickel-stressed (0, 0.0004, 0.04, or 0.08 mM Ni) butterhead lettuce cv. Justyna may improve macronutrient balance and reduce Ni bioaccumulation. Nickel exposure resulted in various unfavorable changes in the macronutrient content together with increase of Ni accumulation in the biomass. Intensive S nutrition of Ni-treated lettuce seems to have no beneficial effect on macronutrient balance. In general, it significantly reduced the root and foliar phosphorus (P), potassium (K), calcium (Ca), and S content and simultaneously did not affect the magnesium (Mg) content in the biomass. At the same time, the nitrogen (N) content was reduced in roots and elevated in shoots. Supplementation of Ni-exposed lettuce with high S doses raised in roots and reduced foliar Ni accumulation; however, Ni content in useable parts exceeded the acceptable limits established for consumption. [ABSTRACT FROM PUBLISHER]

The objective of this study was to determine the effect of nitrogen fertilization rate on growth and quality of leafy lettuce grown during the winter season in non-circulating hydroponic system. Plants were subjected to seven nitrogen (N) concentrations, i.e. 0, 30, 60, 90, 120, 150 and 180 mg L−1N using ammonium nitrate. Nitrogen treatments did not have a significant effect on leaf fresh and dry mass, root fresh and dry mass, number leaves and leaf area. Leaf ascorbic acid and total phenolic content, and antioxidant capacity peaked at 100 and 120 mg L−1N, whereas leaf chlorophyll concentration linearly increased with increasing N application. The results indicate that a solution N concentration of 100 and 120 mg L−1may be sufficient to improve growth, yield and quality parameters of leafy lettuce grown in non-circulating hydroponic system. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, there has been a growing trend towards cultivating leafy vegetables in hydroponic systems. Floating system is an alternative hydroponic system suitable for the production of baby vegetable products, ready-to eat salads and minimally processed leafy vegetables. However, the implementation of this system for the production of fully grown leafy vegetables is not sufficiently studied. The aim of the present study was to examine the potential of floating system as an alternative growing technique of lettuce and rocket plants, as well as the effect of nitrogen (N) application rate (three treatments 100, 150 and 200 mg L'1 of N) on plant physiology, quality and yield during three growing periods. The results showed that increasing the N application rate resulted in an increase of fresh weight of the aerial parts of both lettuce and rocket, while total yield ranged between 12.0 to 41.9 and 8.0 to 30.2 kg m 2 of fresh leaves, for lettuce and rocket, respectively. In addition, increasing the nitrogen rate resulted in higher number of leaves for lettuce and rocket, as well as in a significant increase in the rate of photosynthesis. A similar increase was observed in nitrate, K, Mg and Mn content in the leaves, without however exceeding the permissible limits for nitrates in any case. In conclusion, the use of floating raft technique for lettuce and rocket cultivation in order to produce not only seedlings production or baby products, but also fully grown plants of high quality is highly recommended. [ABSTRACT FROM AUTHOR]

Lettuce is one of the major crops of the United States and can provide a large portion of income for small to medium size growers. Growing lettuce in adverse environmental conditions can have negative effects on quality. Elevated levels of potassium (K) have been shown to positively influence quality in various fruits and vegetables, such as tomato, pepper, and strawberry. However, research is lacking on the effects of elevated levels of K on leafy vegetables such as lettuce. Therefore, seeds of 'Cimmaron' lettuce were sown into a soilless medium and grown in greenhouse conditions at 25/20 °C (day/night). At 27 days after seeding, the plantlets were transferred to 3.8-L plastic nursery pots. Plants were grown under increasing K treatments of 98 (control), 185 (2?), 370 (3?), and 740 (8?) kg·ha-1. Plants were harvested 56 days after seeding. Application of elevated levels of K fertilizer treatments in red romaine lettuce had a positive quadratic effect on plant height increasing 7.0% from the control. Fresh weight (FW) increased 13.0% from the control and dry weight (DW) increased 15.5%. There was linear increase of 30.0% in sucrose concentrations in lettuce leaf tissue. In addition, the increase in K treatments caused an increase of 43.3% in K concentrations in the leaf tissue. In other nutrients, such as Calcium (Ca), Magnesium (Mg), and Sulfur (S), there was a decrease in the leaf tissue of 61%, 52%, and 46% when compared with the control treatment, respectively. The results of the current study suggest that increasing K fertilizer to 185 kg·ha-1 has the best results for plant height, FW and DW, and mineral nutrient concentrations. This study may initiate research that could examine the effects of increasing K fertilizer levels in lettuce or other leafy green vegetables on antioxidant levels and postharvest storability. [ABSTRACT FROM AUTHOR]

Recent results have shown that Azospirillum -inoculated lettuce seeds yield a higher number of transplanted plants with superior traits than non-inoculated controls grown with and without saline stress. However, little available information on the possibility that Azospirillum could improve nutritional and quality market parameters on plants grown under saline conditions and extend life storage has prompted us to explore this issue. In this work, seed inoculation with Azospirillum not only promoted higher biomass but also improved lettuce quality when plants were grown under salt-stress conditions. Compared to non-inoculated controls, higher ascorbic acid content was accompanied by a lower oxidation rate in Azospirillum -inoculated plants. In addition, better overall visual quality was linked to higher chlorophyll content, hue, Chroma, L and lower browning intensity. While the beneficial effects of Azospirillum inoculation were more evident at harvest, some of these continued thereafter. Compared to non-inoculated controls, higher aerial biomass, chlorophyll and ascorbic acid content, better overall visual quality, hue, Chroma and antioxidant capacity, and a lower browning intensity were observed after storage in Azospirillum -inoculated plants grown under salt stress. These results suggest that seed inoculation with Azospirillum not only could improve freshly product quality but also extend storage life in lettuce grown under salt stress. [ABSTRACT FROM AUTHOR]

The research was done at the school vegetable garden of Los Indios in the municipality of Rio Cauto, Granma, from March through April, 2014. The objective was to evaluate the agronomical response of the cultivation of the lettuce (Lactuca sativa. L) variety “Black Seeded Simpson to the foliar application of three doses of Enerplant. The biostimulant was applied in the morning 7 days after transplantation. The doses used were 0.5 mL.ha-1, 1 mL.ha-1 and 1.5 mL.ha-1. The yield components were evaluated. The obtained data were statistically processed using the software package STASTISTICA 6.0 for Windows. Results showed that the three doses had a positive effect on the cultivation yield. Best results were obtained with the application of the 1.5 mL.ha-1 dose. The majority of the evaluated indicators significantly increased. [ABSTRACT FROM AUTHOR]

Greenhouse experiments were conducted in winter growing seasons in order to evaluate the effects of genotype and production methods on yield and nutritional quality of lettuce (Lactuca sativa L.). A three-year (2009-2011) study was conducted by randomized block system in a greenhouse without additional heating. The trial included three genotypes of lettuce (Archimedes RZ, Santoro RZ, Kibou RZ). Each row with these genotypes was exposed to the following variants of covering: control-planting on bare soil, mulching before sowing with PE-black foil, agro textile-covering plants after planting with agro textile (17 g), a combination of mulching + agro textile. Throughout of all the three years of the trial, it was continuously evidenced that the genotype "Santoro RZ" had the biggest heads and the highest yield (15.33 kg 10 m-2), which leads to conclusion that the yield of lettuce is a genotype characteristics. Moreover, the nutritional value (ascorbic acid concentration) has shown that, depending on the method of production, in average, the combination of mulching + agro textile (26.77 mg 100 g-1) had the highest content while the control variant had significantly lower vitamin C content (21.10 mg 100 g-1). The three-year researches have shown that the production method and genotype significantly affect the nitrate content. An average nitrate content was 2196.33 mg kg-1 on the control variant, and 2526.24 mg kg-1 on agro textile. Leafy lettuce of genotyp „Kibou RZ“ had lower nitrate content (2176.85 mg kg-1) compared to „Archimedes RZ“ (2843.05 mg kg-1) and „Santoro RZ“ (2221.37 mg kg-1). However, nitrate concentration in all treatments remained within the European Union's permissible levels. [ABSTRACT FROM AUTHOR]

Effect of pre-harvest continuous light with different red/blue ratio on photon flux density (R/B ratio) on reducing nitrate accumulation was studied by growing lettuce (Lactuca sativaL.) under continuous illumination delivered by light-emitting diodes (LEDs). Results show that nitrate concentration decreased by 1648.0–2061.1 mg kg−1in leaf blade and 962.9–2090.3 mg kg−1in petiole, accompanied by a dramatic increase in soluble sugar content. Compared with monochromatic red light treatment, the decrease in nitrate concentration and increase in soluble sugar content in lettuce under mixed red and blue light were more pronounced. The lowest nitrate concentration was observed in the treatment with R/B ratio of 4. It's concluded that pre-harvest exposure to 48 h continuous LED light could effectively reduce nitrate accumulation in lettuce and this process is strongly affected by R/B ratio of light. This study may provide new perspective for pre-harvest quality management of vegetable, especially in commercial leaf vegetable production under artificial lighting. [ABSTRACT FROM PUBLISHER]