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1
Hakim, M. Arif Rohman, Sumarsono Sumarsono, and Sutarno Sutarno. "Pertumbuhan dan produksi dua varietas selada (Lactuca sativa l.) pada berbagai tingkat naungan dengan metode hidroponik." Journal of Agro Complex 3, no. 1 (June 18, 2019): 15. http://dx.doi.org/10.14710/joac.3.1.15-23.
Повний текст джерелаАнотація:
ABSTRACT The study aims to determine the growth and production of two varieties of lettuce at various levels of shade by hydroponic methods. This research was done by using serie experiment by Randomized Block Design with 3 bloks. Treatment of varieties with 3 series groups on each shade treatment. The shade treatment consisted of four shaded treatment levels (N0), 50% Shade (N1), 60% Shade (N2), and 70% Shade (N3). every shade was tested 2 varieties of lettuce Romain Romain green varieties (V1) and Romain lettuce varieties Tiberius (V2). Parameters observed for plant height, number of leaves, leaf area, fresh weight of plant, and dry weight of plant. The results showed that shade levels increased plant height in 50% and 60% shade, but decreased leaf number, leaf area, wet weight, and dry weight as shade level increased. Tiberius varieties produce higher plant height, leaf number, and wet weight significantly higher than Green Romain varieties. Keywords :Lettuce, shades, varieties, hydroponic ABSTRAK Penelitian bertujuan untuk mengkaji pertumbuhan dan produksi dua varietas selada pada berbagai tingkat naungan dengan metode hidroponik. Penelitian ini dilakukan percobaan seri dengan Rancangan Acak Kelompok (RAK) dengan 3 kelompok. Perlakuan varietas dengan 3 kelompok seri pada setiap perlakuan naungan. Perlakuan naungan terdiri dari empat taraf perlakuan yaitu tanpa naungan (N0), Naungan 50% (N1), Naungan 60% (N2), dan Naungan 70% (N3). Pada setiap naungan dicobakan 2 varietas selada yaitu selada Romain varietas Green Romain (V1) dan selada Romain varietas Tiberius (V2). Parameter yang diamati tinggi tanaman, jumlah daun, luas daun, berat segar tanaman, dan berat kering tanaman. Hasil penelitian menunjukkan bahwa tingkat naungan menaikkan tinggi tanaman pada naungan 50% dan 60%, tetapi menurunkan jumlah daun, luas daun, berat basah, dan berat kering seiring dengan meningkatnya tingkat naungan. Varietas Tiberius menghasilkan tinggi tanaman, jumlah daun, dan berat basah lebih tinggi secara signifikan dibandingkan varietas Green Romain. Kata kunci : Selada, naungan, varietas, hidroponik
2
Makkaew, P., M. Miller, N. J. Cromar, and H. J. Fallowfield. "The influence of the microbial quality of wastewater, lettuce cultivars and enumeration technique when estimating the microbial contamination of wastewater-irrigated lettuce." Journal of Water and Health 15, no. 2 (December 9, 2016): 228–38. http://dx.doi.org/10.2166/wh.2016.145.
Повний текст джерелаАнотація:
This study investigated the volume of wastewater retained on the surface of three different varieties of lettuce, Iceberg, Cos, and Oak leaf, following submersion in wastewater of different microbial qualities (10, 102, 103, and 104E. coli MPN/100 mL) as a surrogate method for estimation of contamination of spray-irrigated lettuce. Uniquely, Escherichiacoli was enumerated, after submersion, on both the outer and inner leaves and in a composite sample of lettuce. E. coli were enumerated using two techniques. Firstly, from samples of leaves – the direct method. Secondly, using an indirect method, where the E. coli concentrations were estimated from the volume of wastewater retained by the lettuce and the E. coli concentration of the wastewater. The results showed that different varieties of lettuce retained significantly different volumes of wastewater (p < 0.01). No statistical differences (p > 0.01) were detected between E. coli counts obtained from different parts of lettuce, nor between the direct and indirect enumeration methods. Statistically significant linear relationships were derived relating the E. coli concentration of the wastewater in which the lettuces were submerged to the subsequent E. coli count on each variety the lettuce.
3
Florijn, P. J., J. A. Nelemans, and M. L. van Beusichem. "Cadmium uptake by lettuce varieties." Netherlands Journal of Agricultural Science 39, no. 2 (June 1, 1991): 103–14. http://dx.doi.org/10.18174/njas.v39i2.16545.
Повний текст джерелаАнотація:
The uptake of Cd by lettuce cultivars was studied in soil and water culture experiments (16 and 8 cultivars, respectively). In the soil experiment, sandy soils from both a Cd-contaminated and a non-contaminated area of the Netherlands were used; the water culture experiment included 3 Cd levels (0, 0.03 and 0.1 mg/litre). Fresh and dry yields of shoots and roots were hardly affected by Cd in either of the experiments. The lettuce cultivars showed a close similarity in shoot Cd concentration, ranging from 8.23 to 10.72 micro g/g DW for the Cd-contaminated soil and from 3.96 to 8.83 micro g/g DW in the water culture at the highest Cd level tested. These results contradict published data on a large genotypic variation in Cd concentration in lettuce [see John, M. K. et al, Environmental Pollution (1976) 10, 163-173]. Based on the narrow range in shoot (and root) Cd concentration between cultivars, it is concluded that it is unwarranted to use lettuce as a pilot plant in comparative physiological investigations on Cd uptake and distribution. (Abstract retrieved from CAB Abstracts by CABI’s permission)
4
Hassim, S. A., and J. H. Chuah. "Lettuce classification using convolutional neural network." Supplementary 6 4, S6 (December 27, 2020): 118–23. http://dx.doi.org/10.26656/fr.2017.4(s6).029.
Повний текст джерелаАнотація:
Determining the varieties of lettuce through image processing and pattern recognition is a part of precision farming. Automatic classification is becoming vital for precision farming practice as it is rapidly sprouting field with the emergence of many applications in agriculture. It is a hassling process to differentiate and identify the lettuce varieties through human capabilities as it is time-consuming and also prone to errors in the identification process. Hence, there is a need to perform this task assisted by a machine capability which makes it faster with even greater accuracy. The objective of this research work is to design lettuce varieties recognition using Convolutional Neural Network (CNN) in MATLAB with an accuracy of at least 90%. CNN was employed to classify seven types of most commonly found lettuce. The CNN model was trained with 7000 leaves and tested with 1800 leaves for the classification of 7 varieties of lettuce. The overall classification accuracy is 97.8%; meanwhile, individual classification accuracies for the selected lettuce varieties, i.e. Butterhead, Celtuce Love, Italian, Red Coral, Lactuca Sativa Lettuce, Red Oakleaf and Salad Grand Rapid are 97%, 99.3%, 98.7%, 96%, 100%, 99.3%, and 94%, respectively. The results from this study have proven the high effectiveness of using a machine learning technique, i.e. CNN, to identify a particular variety of lettuce.
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Yassue, Rafael Massahiro, Diandra Achre, Marcelo Augusto Pastório, Sílvio Douglas Ferreira, Carlos Alberto Dettmer, and Márcia De Moraes Echer. "Nitrogen Fertilization in Two Varieties of Basil." Journal of Agricultural Science 10, no. 7 (June 8, 2018): 403. http://dx.doi.org/10.5539/jas.v10n7p403.
Повний текст джерелаАнотація:
The cultivation of basil is worth mentioning, because it is a very promising crop. The aim of this study was to evaluate the development of the Basil cultivation, cultivar Tuscan lettuce leaf and Alfavaca red basilican, submitted to different doses of nitrogen. The first factor was composed of six nitrogen doses and one control (0, 40, 80, 120, 160, 200, 240 kg ha-1 of nitrogen), and the Second was composed of two cultivars (Alfavaca red basilican and Tuscan lettuce leaf) with four replicates. The basil Alfavaca red basilican cultivar overcame the cultivar Tuscan lettuce leaf in the plant height and diameter of the stem. In the leaf and shoot dry matter variables, the doses that resulted in the greatest increase of dry matter were 128 and 125.62 kg ha-1 of nitrogen for the cultivar Tuscan of lettuce leaf. Both Alfavaca red basilican and Tuscan lettuce leaf were influenced by nitrogen fertilization and the dose of 120 kg ha-1 of nitrogen has the highest potential in the developmental parameters.
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Simonne, Amy, Eric Simonne, Ronald Eitenmiller, and Christine Harris Coker. "Bitterness and Composition of Lettuce Varieties Grown in the Southeastern United States." HortTechnology 12, no. 4 (January 2002): 721–26. http://dx.doi.org/10.21273/horttech.12.4.721.
Повний текст джерелаАнотація:
Lettuce (Lactuca sativa) production historically has been limited in the southeastern United States because of the risk of early bolting and unacceptable bitterness. Small-scale vegetable growers may be able to include lettuce in their production through selection of bolt tolerant and nonbitter varieties. The objectives of this research were to evaluate earliness, bitterness, vitamin E, ascorbic acid, folate, β-carotene, and lutein content in 17 lettuce varieties. Significant difference were found among varieties for days to harvest (DTH) (47 DTH for `Epic' to 37 DTH for `Big Curly'). Observed DTH in this study was consistently 7 to 10 days less than commercial descriptions of the lettuce varieties, due to the use of transplants. Only `Slobolt' and `Greengo' bolted before reaching marketable size. Panelists found that the bitterness was acceptable for most varieties, but not for `Nancy,' `Big Curly,' and `Slobolt'. Significant differences among varieties were also found in vitamin E, ascorbic acid, folate, β-carotene, and lutein. `Redprize' and `Nevada' were the best varieties overall, while `Salinas 88 Supreme,' `Epic,' `Legacy,' `Big Curly,' `Slobolt,' and `Greengo' were unacceptable.
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Rosnina, Rosnina, and Sarah Mauliza. "Optimization of AB-mix Fertilizer on Varieties of Hydroponic Lettuce (Lactuca sativa L.)." Journal of Tropical Horticulture 3, no. 2 (November 23, 2020): 86. http://dx.doi.org/10.33089/jthort.v3i2.56.
Повний текст джерелаАнотація:
Lettuce (Lactuca sativa L.) is a popular leafy vegetable. Most of its varieties are eaten fresh and commonly served as a garnish in fried rice or complementary vegetables in some fast food meals such as burgers and green salads. Nowadays, most lettuce varieties are grown hydroponically, replacing the soil and feeding all nutrients through the water. A hydroponic system is also considered a solution to overcome the shortage of arable lands and good-quality water. This research aims to evaluate the lettuce response towards the application of AB-mix fertilizer in the hydroponic system. This research was designed using Factorial Randomized Block Design (RBD) with two factors (AB mix concentrations and lettuce varieties) and three replications. The results revealed between AB-mix concentrations and lettuce varieties, where the application of AB-mix increased the number of leaves. AB-mix's application gave an effect to all variables observed: plant height, leaf width, leaf number, and leaf chlorophyll but insignificant to root length.
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Simonne, Amarat H., Eric H. Simonne, Ronald R. Eitenmiller, John Owen, and Larry Wells. "Sensory Evaluation of Bitterness in Lettuce Varieties Grown in the Southeastern United States." HortScience 32, no. 4 (July 1997): 600B—600. http://dx.doi.org/10.21273/hortsci.32.4.600b.
Повний текст джерелаАнотація:
The main limiting factor to lettuce production in the Southeast is bitterness. Bitterness in lettuce is associated with sesquiterpene lactones, a bitter principles of the latex of wild lettuce species Lactuca virosa or L. sativa. These wild species are used as parents in the development of virus-resistant cultivars. This study evaluated bitterness of 18 commercial cultivars of lettuce grown following recommended production practices at two locations. Lettuce was hand harvested, refrigerated, washed, and cut into bite-size pieces. Samples were served one by one to a group of 15 panelists, trained with caffeine solutions of increasing bitterness scores (BS; 0% = 0, 0.05% = 2, 0.08% = 5, 0.15% = 10, and 0.20% = 15). A BS of less than seven was acceptable. BS was significantly (P < 0.02) different among varieties. Varieties with lowest BS were `Epic', `Salinas 88 Supreme', `Nevada', `Red Prize', and `Legacy'. For these varieties, mean, most frequent, and highest BS were less than seven. This study suggests that it is possible to grow nonbitter lettuce in the Southeast.
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Boros, Ildikó Fruzsina, László Sipos, Noémi Kappel, László Csambalik, and Marietta Fodor. "Quantification of nitrate content with FT-NIR technique in lettuce (Lactuca sativa L.) variety types: a statistical approach." Journal of Food Science and Technology 57, no. 11 (April 23, 2020): 4084–91. http://dx.doi.org/10.1007/s13197-020-04442-1.
Повний текст джерелаАнотація:
Abstract According to the Commission Regulation (EC) No. 1258/2011, the maximum allowed nitrate content of lettuce is defined within a broad range (2000–5000 mg NO3/kg), depending on harvest season and technology. This study focuses on the identification of the differences in nitrate accumulation between lettuce types and varieties, depending on production technology and on the investigation of the application of non-destructive FT-NIR spectroscopy for nitrate quantification, towards widely used UV–Vis spectroscopy. In the present study, combinations of seasons and technologies (spring × greenhouse, autumn × open field) were employed for the production of types (batavia, butterhead, lollo and oak leaf; both red and green colored); a total of 266 lettuce heads were analyzed. It was found that with standardized technology and conditions, autumn harvested green oak leaf lettuce types accumulated significantly less nitrate, than red oak or lollo leaf types. With spring harvested lettuces, batavia types generally accumulated generally more nitrates than butterhead types. Based on the linear discriminant analysis (LDA) of FT-NIR measurements the four distinct variety types diverge; the lollo type explicitly diverges from batavia and butterhead types. The LDA further revealed, that within lollo and oak leaf variety types, red and green leaved varieties diverge as well. A model was successfully built for the FT-NIR quantification of the nitrate content of lettuce samples (R2 = 0.95; RMSEE = 74.4 mg/kg fresh weight; Q2 = 0.90; RMSECV = 99.4 mg/kg fresh weight). The developed model is capable of the execution of a fast and non-invasive measurement; the method is suitable for the routine measurement of nitrate content in lettuce.
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Captel, A. P., E. A. Pyrkova, and N. L. Naumova. "ABOUT FOOD VALUES AND REQUIREMENTS FOR THE QUALITY OF FRESH GREEN VEGETABLE CROPS - SALADS." Innovations and Food Safety, no. 1 (March 28, 2019): 7–13. http://dx.doi.org/10.31677/2311-0651-2019-23-1-7-13.
Повний текст джерелаАнотація:
The production of green crops, primarily salads, is one of the promising areas of greenhouse vegetable growing. The grounds for this are: year-round demand in the market for fresh greens, high profitability of production, the presence of a wide range of varieties and hybrids belonging to different varieties, an increased level of food culture of the population. The article describes the nutritional value of fresh vegetable greens - lettuce, describes the requirements for consumer characteristics, imposed by the enacted State Standard 33985-2016 “Lettuce. Endive curly, endive Eskariol fresh. Technical conditions”, features of packing, transportation and storage of lettuce are presented. It is established that the leaves of lettuce contain a significant amount of malic, citric and succinic acids, about 2% carbohydrates, 1.5% protein, 0.5% fiber. A large number of trace elements such as manganese, cobalt, copper, iodine and zinc, an excellent ratio in the salad of potassium and sodium. Pigments are represented, including carotene and xanthophyll (from 2.0 to 2.7 mg / 100 g), anthocyanins are present in the colored varieties of lettuce. According to the content of phenolic compounds (represented by cinnamic, caffeic, and chlorogenic acids), leaf varieties are distinguished - up to 192 mg / 100 g, rosette leaves of a head of lettuce - 113-127 mg / 100 g depending on the commercial grade, described unacceptable defects of vegetable greens, methods of laying and specific uniformity of lettuce in the packaging unit.
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Simonne, Eric H., Amarat H. Simonne, Larry W. Wells, Marvin E. Ruf, and John T. Owen. "Field Performance of Lettuce Grown in Alabama." HortScience 32, no. 4 (July 1997): 600A—600. http://dx.doi.org/10.21273/hortsci.32.4.600a.
Повний текст джерелаАнотація:
While lettuce is one of the most widely consumed vegetables in the United States, production is mainly concentrated in the western states. This research investigated the feasibility of lettuce production in the Southeast (SE), where downy mildew, tip burn, bitterness, bolting, and postharvest handling are potential production problems. Lettuce varieties were evaluated on plastic mulch and drip irrigation under several growing conditions. Cultivar and location significantly (P < 0.01) affected yield and transplant survival rate. Following these tests, 'Salinas 88 Supreme', 'Legacy', 'Bullseye', 'Epic' (crisphead); 'Nancy', 'Nevada', 'Ostinata' (butterhead); 'Parris Islands', 'Augustus' (Romaine); and 'Red Salad Bowl', 'Red Prize', and 'Slobolt' (loose leaf) are considered best-performing lettuce varieties for Alabama. These results, along with bitterness evaluation, support the potential for lettuce production in the SE.
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Knight, C., R. W. K. Holland, and I. R. Wright. "RESISTANCE OF LETTUCE VARIETIES TO POWDERY MILDEW." Annals of Applied Biology 108, S1 (April 1986): 150–51. http://dx.doi.org/10.1111/aab.1986.108.s1.150.
Повний текст джерела
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Yusuf N, Muhammad, and Muhamad Yusuf. "Pengaruh Pupuk Organik Cair (POC) Terhadap Pertumbuhan Dan Hasil Tiga Varietas Tanaman Selada (Lactuca sativa L.)." Jurnal Agrium 14, no. 2 (November 25, 2017): 37. http://dx.doi.org/10.29103/agrium.v14i2.878.
Повний текст джерелаАнотація:
This study aims to find out organic fertilizers and crops and lettuce products. The study was conducted in Blang Dalam Village Geunteng Nisam District, North Aceh District, from September to November 2017 with a height of 6 meters above sea level. This research will use Randomized Block Design (RAK) Factorial pattern. There are two factors studied, namely: Liquid organic fertilizer (C) consists of 4 levels, namely: C0 = control (without fertilizer), C1 = application of liquid organic fertilizer 4 cc / liter of water, C2 = application of liquid organic fertilizer 8 cc / liter of water, C3 = application of liquid organic fertilizer 12 cc / liter of water. Lettuce varieties (V) consists of 3 levels, namely: V1 = Grand Rapids Varieties, V2 = Lettuce Varieties, V3 = Red Coral Varieties. Thus there were 12 treatment combinations with 3 replications, so there were 36 experimental units. Based on the results of the study showed that: application of liquid organic fertilizer gives a very different effect on growth and yield of lettuce plants and there is a very real interaction
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Malarz, Janusz, Klaudia Michalska, and Anna Stojakowska. "Stem Lettuce and Its Metabolites: Does the Variety Make Any Difference?" Foods 10, no. 1 (December 29, 2020): 59. http://dx.doi.org/10.3390/foods10010059.
Повний текст джерелаАнотація:
The objective of the present study was to characterize chemical composition of hitherto unexamined aerial parts of Lactuca sativa var. angustana cv. Grüner Stern. In contrast to leafy and head varieties of the lettuces, asparagus lettuce grown in Europe is much less studied. Fractionation of a methanolic extract from leaves of L. sativa cv. Grüner Stern, supported with HPLC/DAD and 1H NMR analysis, led to the isolation and/or identification of numerous terpenoid and phenolic compounds, including five apocarotenoids—(-)-loliolide, (+)-dehydrovomifoliol, blumenol A, (6S,9S)-vomifoliol, and corchoionoside C; three sesquiterpene lactones; two lignans—((+)-syringaresinol and its 4-O-β-glucoside); five caffeic acid derivatives; and three flavonoids. Some of the compounds, to the best of our knowledge, have never been isolated from L. sativa before. Moreover, monolignols, phenolic acids and a tryptophan-derived alkaloid were found in the analyzed plant material. Stems, leaves and shoot tips of the asparagus lettuce were examined to assess their phenolics and sesquiterpene lactone content as well as DPPH scavenging activity. Another stem lettuce—L. sativa var. angustana cv. Karola, two cultivars of leafy lettuces and one species of wild lettuce—L. serriola, were also examined as a reference material using HPLC/DAD. The results have been discussed regarding our previous studies and the literature data available.
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Fernandes Colombari, Lidiane, Vitor Massami Imaizumi, Luiz Felipe Guedes Baldini, Prínscilla Pâmela Nunes Chaves, and Rumy Goto. "WINTER COVER CROPS SOWING SYSTEMS FOR PLANTING LETTUCE." COLLOQUIUM AGRARIAE 14, no. 3 (September 1, 2018): 169–78. http://dx.doi.org/10.5747/ca.2018.v14.n3.a239.
Повний текст джерелаАнотація:
The sowing system, as well as the species used as covercrops, may interfere with the production of straw and the development of further crops. The objective of this research was to evaluate sowing systems for black oat (Avena strigosaSchreb) and white lupine (Lupinus albus) as cover crops, the dry matter production of these plants and their influence on Americana and Curly lettuces yield. Two experiments were performed, one for each lettuce cultivar. The experimental design was composed of 8 treatments (factorial 4x2), evaluated in randomized blocks, with five replications. The first factor is related to four soil coverages (black oat, white lupine, black oat + white lupine and weed) and the second one is the sowing system (handand mechanized in line). The cover plants drying was performed 47 days after planting and the amount of dry matter produced in the area (straw) was then measured. After 30 days from drying, varieties of Curly and Americana lettuce were planted under straw. The lettuce cultivars were evaluated for fresh mass, shoot height and head diameter. For both lettuces, the benefit ofgreen manure was higher using black oat only or combinedwith white lupine, either handor mechanized sowed.
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Zdravkovic, Jasmina, Gordana Acamovic-Djokovic, Jelena Mladenovic, Rados Pavlovic та Milan Zdravkovic. "Antioxidant capacity and contents of phenols, ascorbic acid, β-carotene and lycopene in lettuce". Chemical Industry 68, № 2 (2014): 193–98. http://dx.doi.org/10.2298/hemind130222043z.
Повний текст джерелаАнотація:
The antioxidant activity of three lettuce varieties (Lactuca sativa L.) Emerald, Vera and Neva, cultivated in two kinds of protected spaces, a glasshouse and a plastic greenhouse, under controlled conditions, was determined. The content of antioxidant compounds: total phenols, flavonoids, L-ascorbic acid, ?-carotene and lycopene, were determined in ethanolic extracts of the lettuce with spectrophotometric methods. The largest content of total phenols (78.98 ? 0.67 mg GAE/g of dry extract) was found in ethanolic extract of the lettuce variety Neva cultivated in a plastic greenhouse, whereas the largest content of flavonoids (35.45 ? 0.95 mg RU/g of dry extract) was displayed in the lettuce Emerald cultivated in a glasshouse. It was observed that the lettuce cultivated in the glasshouse contained a somewhat higher content of L-ascorbic acid than the lettuce same variety from plastic greenhouse. The content of lycopene in the examined lettuce is negligible, and the content of ?-carotene is low. On the other hand, the high content of phenolic components causes favourable antioxidant properties found in all varieties of examined lettuce.
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Puri, Krishna D., Gary E. Vallad, Qing-Ming Qin, Ryan J. Hayes, and Krishna V. Subbarao. "Harvest of Lettuce from Verticillium-Infested Fields Has Little Impact on Postharvest Quality." Plant Disease 103, no. 4 (April 2019): 668–76. http://dx.doi.org/10.1094/pdis-04-18-0546-re.
Повний текст джерелаАнотація:
Verticillium wilt of lettuce, caused by the soilborne pathogen Verticillium dahliae, poses a serious threat to the California lettuce industry. Knowledge of disease development and its impact on postharvest marketability would facilitate better management of the affected fields. This study investigated postharvest marketability of 22 lettuce varieties harvested from two Verticillium-infested commercial lettuce fields in Salinas and Watsonville, CA, in 2005 using a randomized complete block design. Periodic sampling to monitor disease in several crisphead varieties in the field demonstrated that root symptoms developed quickly at later stages of heading, followed by the onset of foliar symptoms as the crop reached harvest maturity. Harvested marketable heads were vacuum cooled soon after harvest to about 4°C and maintained at this temperature in commercial coolers. The impact of V. dahliae on postharvest marketability was assessed based on the percentage of heads per case deemed marketable following 1, 2, and 3 weeks of refrigerated storage. Across both field experiments, the average disease incidence and postharvest marketability ranged from 4.2 to 87.5% and from 69.4 to 100.0%, respectively, among lettuce types and varieties. The Pearson correlation analysis detected no significant relationship between disease incidence and postharvest marketability across all varieties tested (r = 0.041, P = 0.727), or within lettuce types, even though V. dahliae was recovered from 34% of the plants harvested, and recovery ranged from 0 to 73.3% for V. dahliae and from 10 to 91.7% for non-V. dahliae (V. isaacii or V. klebahnii) species. These findings demonstrate that growers can harvest lettuce from an infested field before foliar symptoms develop with negligible impact by Verticillium spp. on postharvest marketability or quality.
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Fontana, Larissa, Claudia A. Rossi, Silviane Z. Hubinger, Marcos D. Ferreira, Marta H. F. Spoto, Fernando C. Sala, and Marta R. Verruma-Bernardi. "Physicochemical characterization and sensory evaluation of lettuce cultivated in three growing systems." Horticultura Brasileira 36, no. 1 (March 2018): 20–26. http://dx.doi.org/10.1590/s0102-053620180104.
Повний текст джерелаАнотація:
ABSTRACT There exists a growing demand and promising market for new lettuce varieties in Brazil. Cv. Brunella is an innovative lettuce variety which mixes crisp lettuce and head lettuce characteristics besides being adapted to the Brazilian growing conditions. The physicochemical and sensory quality of this lettuce, cultivated under different growing systems, was evaluated. The conventional planting and the hydroponic systems were carried out in the experimental area of the Universidade Federal de São Carlos, São Paulo State, Brazil and the organic system was done by certified organic producer in the municipality of Cordeirópolis. After harvesting, leaf area, leaf size, unit leaf area, fresh mass, mass loss, turgor pressure, instrumental color, pH, total titratable acidity (TTA), total soluble solids (TSS), total phenolic compounds (TPC), and sensory characterization were evaluated. We verified that the growing system influenced on physicochemical traits producing lettuces of different sizes, weights and stability. For pH, TSS and TPC, difference among the three growing systems was not observed. For TTA, the hydroponic sample showed higher acidity. About sensory evaluation, the testers noticed difference for green color, thickness, size and leaf crispness, grass aroma and bitter taste. The samples cultivated in conventional and hydroponic systems showed greater preference and purchase intention.
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Лещук, Н. В. "Seed Production of Cutting Lettuce Varieties: Economical Facets." Plant varieties studying and protection, no. 1(13) (May 20, 2011): 35–37. http://dx.doi.org/10.21498/2518-1017.1(13).2011.60057.
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Лещук, Н. В. "Lettuce varieties selection for open soil conveyer breeding." Plant varieties studying and protection, no. 3 (June 26, 2006): 90–98. http://dx.doi.org/10.21498/2518-1017.3.2006.67713.
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Baz, Hanna, Matthew Creech, Jianjun Chen, Haijun Gong, Kent Bradford, and Heqiang Huo. "Water-Soluble Carbon Nanoparticles Improve Seed Germination and Post-Germination Growth of Lettuce under Salinity Stress." Agronomy 10, no. 8 (August 13, 2020): 1192. http://dx.doi.org/10.3390/agronomy10081192.
Повний текст джерелаАнотація:
Seed germination is a critical developmental phase for seedling establishment and crop production. Increasing salinity stress associated with climatic change can pose a challenge for seed germination and stand establishment of many crops including lettuce. Here, we show that water soluble carbon nanoparticles (CNPs) can significantly promote seed germination without affecting seedling growth. Twenty-seven varieties of lettuce (Lactuca sativa) were screened for sensitivity to germination in 150 and 200 mM NaCl, and six salt-sensitive varieties (Little Gem, Parris Island, Breen, Butter Crunch, Muir, and Jericho) were selected and primed with 0.3% soluble carbon nanoparticles. Pretreatment with CNPs significantly improved seed germination under 150 mM NaCl and high temperature. CNP treatment slightly inhibited the elongation of primary roots but promoted lateral root growth and accumulation of chlorophyll content of seedlings grown under salt stress. Despite different lettuce varieties exhibiting a distinct response to nanoparticle treatments, results from this study indicate that soluble nanoparticles can significantly improve lettuce seed germination under salinity stress, which provide fundamental evidence on the potential of nanoparticles in agricultural application to improve crop yield and quality under stressful conditions.
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van de Wiel, Clemens, Paul Arens, and Ben Vosman. "Microsatellite retrieval in lettuce (Lactuca sativa L.)." Genome 42, no. 1 (February 1, 1999): 139–49. http://dx.doi.org/10.1139/g98-119.
Повний текст джерелаАнотація:
By using enriched genomic libraries, microsatellite-containing sequences were isolated from lettuce (Lactuca sativa) with high efficiency. With this approach, a sizeable fraction (up to 55%) of the clones contained a microsatellite. In about half of these clones, primers could be designed for PCR amplification of the microsatellite. This yielded 28 primer sets amplifying unambiguously scorable products, of which 26 showed polymorphisms in a test set of six lettuce varieties. Practically all microsatellite-amplifying primer sets yielded products in lettuce's nearest relative, L. serriola, but only half of the primer sets yielded products in the more distant species L. saligna and L. virosa. An average polymorphism information content (PIC) value of 0.55 and an average number of 3.5 alleles per locus were in the normal range for a self-fertilizing species like lettuce. In addition, the incidental cloning of a microsatellite-containing repeat family, apparently specific for Lactuca, is reported and the implications for the efficient retrieval of single-locus microsatellite sequences are discussed. The microsatellite loci isolated will be useful for distinguishing lettuce cultivars and for screening diversity of genetic resources.Key words: STMS, SSR, repeats, genetic diversity.
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MSILINI, NAJOUA, HOUNEIDA ATTIA, MOKDED RABHI, NAJOUA KARRAY, MOKHTAR LACHAÂL, and ZEINEB OUERGHI. "RESPONSES OF TWO LETTUCE CULTIVARS TO IRON DEFICIENCY." Experimental Agriculture 48, no. 4 (July 18, 2012): 523–35. http://dx.doi.org/10.1017/s0014479712000439.
Повний текст джерелаАнотація:
SUMMARYA comparative study of two lettuce varieties (Lactuca sativa: ‘Romaine’ and ‘Vista’) was conducted to understand the effect of iron deficiency on growth, biomass allocation, chlorophyll fluorescence and root and leaf enzymatic activity. After 15 days of growth in hydroponic solution under Fe-deficient and Fe-sufficient conditions, leaf chlorophyll concentration, activities of ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco) in leaves extract, ferric chelate reductase (FCR) and phosphoenolpyruvate carboxylase (PEPC) in root extracts were measured. We found that there were significant differences in fresh matter accumulation and pigment concentration between the varieties. Fresh weight and total leaf area and leaf number were significantly reduced under iron deficiency. There was also a significant decrease in photosynthetic pigment concentration in both varieties. In response to Fe deficiency, ‘Vista’ variety showed higher FCR and PEPC activities compared to ‘Romaine’ variety. Moreover, this increase was accompanied by an enhanced accumulation of phenolic compound in roots of ‘Vista’ variety. These findings show that ‘Romaine’ was more affected by iron deficiency than ‘Vista’.
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Favarato, Luiz Fernando, Maurício José Fornazier, Frederico Jacob Eutrópio, Rogério Carvalho Guarçoni, and Lidiane Mendes. "Cropping system to produce lettuce in autumn season at different elevations." OCTOBER 2020, no. 14(10):2020 (October 20, 2020): 1555–62. http://dx.doi.org/10.21475/ajcs.20.14.10.p1769.
Повний текст джерелаАнотація:
Lettuce is an annual herbaceous plant, native to the mild climate regions of the northern Mediterranean. Lettuce varieties can likely be developed well in mild temperatures, but the cold and frosty winds of the autumn/winter season may damage the leaves. Their cultivation under low tunnels is an alternative to reduce this problem. This study was carried out with the aim of evaluating the influence of different cropping systems on the productive performance of lettuce in the autumn/winter cropping season. The experiments were installed following a split plot scheme with three cropping systems: (i) Open field with black polyethylene mulching (BPM); (ii) low tunnel (LT); (iii) Open field cropping (OFC) system without BPM. Three lettuce varieties of different groups were used in the subplots, with a total of nine treatments. The experimental design was of randomized blocks with four replications, at two altitudes (700 and 950 m). The number of leaves per plant, stem length, head diameter, fresh and dry matter mass per plant, leaf area index, and specific leaf area were evaluated. LT should be used for lettuce cultivation at an altitude of 950 m, as it provided higher productive performance in the autumn season. The use of the low tunnel provided for the production of lettuce plants with thinner leaves and better visual appearance, at an altitude of 700 m.
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Kovácsné Madar, Ágota, Tímea Rubóczki, and Mária Takácsné Hájos. "Lettuce production in aquaponic and hydroponic systems." Acta Universitatis Sapientiae, Agriculture and Environment 11, no. 1 (December 1, 2019): 51–59. http://dx.doi.org/10.2478/ausae-2019-0005.
Повний текст джерелаАнотація:
Abstract Besides soil cultivation, there are other alternative methods such as the aquaponic and the hydroponic technology. In our research, four lettuce varieties (‘Edina’, ‘Május királya’, ‘Lollo Rossa’, and ‘Lollo Bionda’) were compared by the use of different systems. In hydroponics, the direct nutrient supply resulted higher leaf weight. In addition, multiple values of nitrate (269.50–406.50 mg kg-1) were measured in this system compared to the aquaponic system (23.25–170.00 mg kg-1). The ‘Lollo Rossa’ stood out with higher element content (Zn, B, and Mg) in both cultivation methods. In conclusion, it can be stated that higher nutrient content in hydroponics resulted higher leaf weight, but nitrate values were also higher in this unit. Aquaponic technology can be used to produce high-quality (low-nitrate) lettuce with the ‘Lollo Rossa’ and ‘Lollo Bionda’ varieties.
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Pedrilho, Giovane Munhoz, João Vitor da Silva Fernandes, André Ribeiro Da Costa, Anny Rose Mannigel, Daniele Fernanda Felipe, Graciene De Souza Bido, Ricardo Andreola, Roberto Rezende, Paulo Sérgio Lourenço De Freitas, and Antônio Carlos Andrade Gonçalves. "Nitrogen Fertigation in Lettuce Culture." Journal of Agricultural Studies 8, no. 1 (March 2, 2020): 126. http://dx.doi.org/10.5296/jas.v8i1.15450.
Повний текст джерелаАнотація:
Lettuce (Lactuca sativa L.) is the most consumed vegetable in the world and in Brazil, representing as an important dietary source of vitamins, fiber and minerals to population. The aim of this study was to evaluate the yield of lettuce against nitrogen doses applied via fertigation, as well as the quality of the administered fertilizer solution. The test was carried out in an agricultural area located in the Doutor Camargo municipality, Northwestern of Paraná State, Brazil. The experiment was designed in a completely randomized design with seven treatments: T1 control - 0 kg ha-1 urea (0 kg N ha-1); T2 - 25 kg ha-1 urea (11.25 kg N ha-1); T3 - 50 kg ha-1 urea (22.5 kg N ha-1); T4 - 75 kg ha-1 urea (33.75 kg N ha-1); T5 - application of 100 kg ha-1 urea (45 kg N ha-1); T6 - 125 kg ha-1 urea (56.25 kg N ha-1); T7 - 150 kg ha-1 urea (67.5 kg N ha-1). Each treatment had six repetitions. Seeds from Dora (American lettuce) and Vera (curly lettuce) varieties were used for seedling production. Nutrients were applied to the crop by fertigation at 15 and 30 days after transplanting the seedlings to the seedbeds. Fresh shoot mass (weight), stem diameter, root length and productivity were assessed. Results showed that nitrogen fertilization via fertigation significantly influenced the growth and yield variables of plants from both Dora and Vera varieties.
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Franquera, Edmar. "Leaf Morphological Chara cteristics of Leaf Lettuce (Lactuca sativa L.) as Affected by Different Colored Plastic Mulch." Current Agriculture Research Journal 3, no. 1 (June 17, 2015): 20–25. http://dx.doi.org/10.12944/carj.3.1.04.
Повний текст джерелаАнотація:
Looseleaf and Romaine lettuce were grown in a vegetable experimental station in the University of the Philippines Los Banos to determine the effect of the different colored plastic mulch on the leaf morphological characteristics of the two lettuce varieties. A split plot following the Randomized Completely Block Design was used. Results of the study showed that red plastic mulch exhibited better response in terms of the different leaf morphology of the leaf lettuce. Lettuce leaf length, leaf diameter, leaf fresh and dry weight were higher when grown with red plastic mulch compared with the other colored plastic mulch. The result of the study showed that the color of the mulch had significant effect on the leaf morphological characteristics of the leaf lettuce.
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Gonzaga, T. O. D., C. Araujo, A. L. Andrade, J. M. Dos Santos, G. B. Silva, and V. L. Silva. "Production of lettuce changes (lactuca sativa) submitted to different doses of Silicon." Scientific Electronic Archives 13, no. 1 (January 3, 2020): 1. http://dx.doi.org/10.36560/1312020863.
Повний текст джерелаАнотація:
The objective of this work was to evaluate the effect of different doses of silicon on the production of lettuce seedlings. The treatments were arranged in a 4x2 factorial scheme, totaling 8 treatments. The first factor corresponded to 4 Si doses (Ca silicate) added to the substrate for seedling production (0; 13.3; 32.3 and 53.2 g.kg-1 of Si on the substrate). The second factor corresponded to two varieties of lettuce, being Mônica SF31 (Crespa) and Rafaela (Americana). The experimental design was the completely randomized, with 4 replicates. The number of leaves (NF), fresh aerial mass (MFPA), dry shoot mass (MSPA), fresh radicular mass (MFRA) and root dry mass (MSRA) were evaluated. Data were submitted to analysis of variance by the F test, and the means of the treatments compared by the Tukey test at 5% probability. The seedlings of the Mônica SF31 and Rafaela lettuce varieties do not present differences regarding the Si requirement for the production of MFPA, MSPA, MFRA and MSRA. The application of Si to the substrate can be a viable alternative for the production of lettuce seedlings with higher NF, MFPA, MSPA, MFRA and MSRA. Doses of 32.0 to 43.7 g.kg-1 of Si in the substrate are suitable for higher production of MFPA, MSPA, MFRA and MSRA of lettuce Mônica SF31. Doses of 31.5 to 39.8 g.kg-1 of Si in the substrate are suitable for higher production of MFPA, MSPA, MFRA and MSRA of Rafaela lettuce seedlings.
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Pires, T. S., A. J. Braz, B. L. L. Coelho, J. P. M. Carvalho, and A. P. S. Siqueira. "Shelf life of lace varieties under different kinds of packaging and harvesting times." Scientific Electronic Archives 13, no. 1 (January 3, 2020): 18. http://dx.doi.org/10.36560/1312020980.
Повний текст джерелаАнотація:
The objective of this work was to evaluate the shelf life of purple curly and crisp lettuce varieties in two different harvesting periods with different borehole, no bore and no packaging, evaluating soluble solids content, titratable acidity and mass loss. All parameters were statistically significant, but the most important was the loss of mass, indicating that the treatments with the use of the package without bore harvested at 5:30 proved to be the most effective in the conservation of lettuce during the epochs.
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Bobkova, O. N., and V. V. Skorina. "ASSESSMENT OF THE RELATIONSHIP BETWEEN THE MAIN ECONOMICALLY VALUES OF THE VARIETY OF LETTUCES." Vegetable crops of Russia, no. 2 (April 22, 2019): 43–48. http://dx.doi.org/10.18619/2072-9146-2019-2-43-48.
Повний текст джерелаАнотація:
Expanding the range of vegetable crops, including green ones, through the introduction of new varieties into production is an important task. The study and evaluation of the original material of the salad, the features of cultivation in different periods, will allow to identify samples of a complex of economically valuable traits for the selection of culture, which is relevant for the creation of varieties in Belarus. Research was carried out on the experimental field of the Department of horticulture of the Belarusian state agricultural Academy in 2013-2015. The article assesses the relationship between the main economically valuable features of varieties of lettuce when grown in the spring (seedling method) and spring and summer sowing in the open ground. In lettuce plants of the headed variety, the sign “the mass of the vegetative part of the plant” strongly depends on the sign “diameter of the head” (r=0.640 - with the seedling method and r=0.809 - with the spring sowing period), “leaf width” (r=0.685 and r=0.790, respectively). A high connection is also established between the signs "leaf length" and "leaf width" (r=0.702 - with the spring sowing period and r=0.749 - with the seedling method). In leaf lettuce plants, a strong correlation was noted between the signs “leaf length” and “plant height” (r=0.706 for summer and r=0.810 for spring planting), diameter of the rosette of leaves (r=0.564 for summer and r=0.810 - at the spring sowing time). The average feedback for leaf lettuce varieties is revealed between the signs “leaf width” and “number of leaves” (r=-0.444 - for spring and r=-0.458 - for summer sowing time). The majority of morphological signs, depending on the time of cultivation, are related to each other by average correlation links (the correlation coefficient ranged from 0.458 to 0.531).
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Franquera, Edmar, and Renato Mabesa. "Effect of Plastic Mulch Color on Leaf Anatomy of Lettuce (Lactuca sativa L.)." Current Agriculture Research Journal 3, no. 2 (December 7, 2015): 105–8. http://dx.doi.org/10.12944/carj.3.2.03.
Повний текст джерелаАнотація:
Two lettuce (Lactuca sativa L.) varieties (Looseleaf and Romaine) were grown with five colored (silver, red, orange, yellow, green) plastic mulches to determine their effects on the leaf anatomical structure of lettuce. The experiment was laid in a Split Plot Randomized Completely Block Design. The result of the study showed that Romaine lettuce (8.80) had a higher number of stomata compared with Looseleaf (6.73) however; in terms of stomata length the Looseleaf had longer stomata (18.63 µm) compared with Romaine (16.42 µm). More stomata were observed in lettuce grown with red plastic mulch. However, the number of stomata did not differ among the various colored plastic mulches. Longer stomata were observed in lettuce grown with red plastic mulch, compared with lettuce grown with the other colored plastic mulches. The study showed that the color of the plastic mulch had a significant effect on the leaf anatomy of lettuce and red plastic mulch could be used to enhance the length of the stomata which may affect the growth of the lettuce.
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Lafta, Abbas, and Beiquan Mou. "Evaluation of Lettuce Genotypes for Seed Thermotolerance." HortScience 48, no. 6 (June 2013): 708–14. http://dx.doi.org/10.21273/hortsci.48.6.708.
Повний текст джерелаАнотація:
Thermoinhibition of lettuce (Lactuca sativa L.) seed germination is a common problem associated with lettuce production. Depending on lettuce cultivars, seed germination may be inhibited when temperatures exceed 28 °C. The delay or inhibition of seed germination at high temperatures may reduce seedling emergence and stand establishment of lettuce in the field, leading to a reduction in economic yield. To identify heat-tolerant lettuce genotypes, lettuce varieties and germplasm accessions were screened for the ability to germinate under high-temperature stress. Twenty-four to 26 genotypes were selected from each lettuce types (crisphead, romaine, butterhead, loose leaf, and wild species) and their seeds were placed in petri dishes to test their ability to germinate at high temperatures (29 and 34 °C) as compared with controls at 24 °C. Some lettuce genotypes showed thermotolerance to 34 °C (less than 20% reduction in germination) such as Elizabeth, PI 342533, PI 358025, Florida Buttercrisp, Kordaat, Corsair, FL 50105, PRO 425, PI 278070, Noemie, Picarde, Gaillarde, L. serriola (PI 491112, UC96US23, PI 491147), L. virosa (PI 274378 D), L. saligna (PI 491159), and primitive (PI 187238 A, PI 289063 C). The germination rates were consistent with the germination percentage at the high temperatures. Seed germination in the field was very low and positively correlated with seed germination at 29 and 34 °C. The highest field germination percentages (greater than 40%) were observed in Belluro, Mantilia, Mid Queen, Headmaster, PRO 874, PRO 425, FL 50105, Corsair, Romaine SSC 1148, Romaine Romea, Green Forest, Grenadier, FL 43007, Squadron, Xena, Noemie, Green Wave, Picarde, and Red Giant. The results of this study indicated that lettuce genotypes differ greatly in their ability to germinate at high temperatures as determined by the percentages and the rates of germination. Our research indicates that thermoinsensitive varieties could be used to expand lettuce production seasons in warm and low land cost areas and reduce the need for seed priming, lowering the production costs. The information may also be useful for growers to better choose cultivars for warm environments and for lettuce breeders to improve the crop for adaptation to global warming and climate change.
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Mária Takácsné Hájos. "Correlation between cultivation methods and quality in some vegetable species." Acta Agraria Debreceniensis, no. 49 (November 13, 2012): 313–17. http://dx.doi.org/10.34101/actaagrar/49/2550.
Повний текст джерелаАнотація:
Quality parameters of 5 table root varieties were tested on 3 sowing dates with different cultivation methods: open field on 15 April and 9 July 2010 and under plastic tents on 19 August. The highest red pigment content (betanin) was measured in the varieties Akela and Mona Lisa (~ 80 mg 100 g-1) of the second (July) crop. This crop is in general use in Hungary. In comparison, in the late sown varieties (August, under plastics) a further pigment increase (10–20 mg 100 g-1) was observed in the same varieties as related to the earlier sowing dates. Yellow pigments (vulgaxanthins) showed similar trends. Roots of the late sowing date (with harvest in December) contained the highest vulgaxanthin values (103.3–124.18 mg kg-1).Varieties reacted differently to temperature changes during the production period and thus to sugar accumulation. In the second crop (July) higher water soluble solids content was measured on the average of varieties (10.12%) in comparison to the April sowing (7.76%). Beetroots of the spring sowing are recommended for fresh market while the second (July) crop with autumn harvest can satisfy industry requirements. Late sowing under unheated plastic tents supply us with fresh beetroot in late autumn and early winter and prolong the usability of plastic tents. Six lettuce species/subspecies were tested in the open field and under plastic tents in 3 repetitions for nitrate nitrogen, vitamin-C, polyphenol (gallus acid equivalent – mg GAE 100 g-1) and mineral element (Ca, K, Mg, Na) contents. Our measurements showed lower nitrate nitrogen values under plastic than in the open field (89.10± 8.13 and 127.06±14.29 mg kg-1) on the average of genotypes. Lettuce grown in the field had higher vitamin-C content (1.4 mg%) which is nearly 50% more than in plants under plastic. The highest polyphenol content was found in samples from the field with a conspicuous value of 804.17±56.47 mg GAE 100 g-1 in Piros cikória. Samples grown under plastic were richer in mineral elements (Ca, K, Mg, Na) which can be explained by the higher nutrient content of the soil. In this environment superior Mg content was observed in Edivia (4616.33±311.21 mg kg-1).
Besides the well- known headed lettuce, Piros cikória (Red chicory),the red leaved Lollo Rossa and Tölgylevel (Oak leaf lettuce) should bementioned which well deserve further testing in order to supply us with nourishing, healthy food.
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Welbaum, Gregory, and Charlie O'Dell. "545 PB 087 SUMMER LETTUCE PRODUCTION POTENTIALS FOR HIGHER ELEVATIONS." HortScience 29, no. 5 (May 1994): 509e—509. http://dx.doi.org/10.21273/hortsci.29.5.509e.
Повний текст джерелаАнотація:
Greenhouse grown transplants of 23 lettuce varieties were produced in 1” diameter speedling flats, seeded May 1, transplanted to the field in early June when plants were 4 weeks of age. Transplants were grown in a commercial potting media of peat-vermiculite-perlite. Loose leaf, butterhead, crispbead or iceberg and cos types were included, field-planted at the Elam Swarey farm in Burkes Garden, Tazewell County, Virginia, at an elevation of 3,400 ft. above sea level. No crisphead (iceberg) varieties were found to be satisfactory in yield or quality for area conditions. Of loose leaf varieties, `New Red Fire' and `Red sails' were judged highly adapted for high elevation summer production at sites above 2,000' elevation and/or for fall production at lower Piedmont and coastal areas for October and November harvests. `Tiara', a dark green loose leaf was judged the best of its type in this test. Of the cos types, `Pyramid' and `Ideas' were best adapted to high elevation summer production or lower elevations fall production. Of the butterhead types, `Condor' and `Encore' were suited to higher elevations, `Condor' showing more heat tolerance.
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Cole, Rosemary A., Wendy Riggall, and Alan Morgan. "Electronically monitored feeding behaviour of the lettuce root aphid (Pemphigus bursarius) on resistant and susceptible lettuce varieties." Entomologia Experimentalis et Applicata 68, no. 2 (August 1993): 179–85. http://dx.doi.org/10.1111/j.1570-7458.1993.tb01701.x.
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Křístková, E., I. Doležalová, A. Lebeda, V. Vinter, and A. Novotná. "Description of morphological characters of lettuce (Lactuca sativa L.) genetic resources." Horticultural Science 35, No. 3 (August 12, 2008): 113–29. http://dx.doi.org/10.17221/4/2008-hortsci.
Повний текст джерелаАнотація:
Lettuce (<i>Lactuca sativa</i>) is the most important crop in the group of leafy vegetables. It is characterized by considerable morphological and genetic variation. The crop comprises seven main groups of cultivars (including oilseed lettuce) differing phenotypically; they are usually described as morphotypes. Lettuce breeding is primarilly focused on various morphological features and resistance against diseases and pests. The accurate description of lettuce germplasm provides basic information useful for lettuce breeders. The construction of a lettuce descriptor list has been stimulated by the international genebank community. This list consists of 55 descriptors with 15 elucidated by figures. It provides a tool for detailed characterization of and discrimination within the intraspecific variation of <i>L. sativa</i>, verification of old varieties, and identification of putative duplicates and gaps in germplasm collections. These descriptors, along with descriptors of wild <i>Lactuca</i> species, provide an efficient analytical tool for studying the complex morphological variability of this genus and relationships among the species.
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Gazula*, Aparna, Matthew D. Kleinhenz, Joseph C. Scheerens, Peter P. Ling, and John G. Streeter. "Temperature and Genotype Affect Anthocyanin Concentrations in Lettuce (Lactuca sativa)." HortScience 39, no. 4 (July 2004): 864A—864. http://dx.doi.org/10.21273/hortsci.39.4.864a.
Повний текст джерелаАнотація:
In addition to their physiological and metabolic roles, anthocyanin (Antho) levels in lettuce contribute to visual and nutritional value-based assessments of crop quality. Although 7 genes are now thought to help regulate Antho synthesis, deposition and/or degradation in lettuce, the genetic and abiotic controls of Antho levels remain less well characterized in lettuce than other plants. Previous greenhouse studies demonstrated that Antho levels in diverse lettuce varieties are a function of temperature and lighting regimen. Here, three strongly related Lolla Rossa-type varieties (`Lotto', `Valeria', and `Impuls') varying in the number of genes controlling intensity of anthocyanins were subjected to differential temperature conditions in growth chambers to better discern the independent and interactive effects of temperature (T) and variety (V) on Antho levels. Fifteen day-old seedlings were placed into one of three chambers maintained at 20 °C day/night (D/N), 30 °C/20 °C D/N or 30 °C D/N. Antho levels were measured in leaf tissue collected 30 d after transplanting. The entire experiment was replicated twice. Although significant, the T x V interaction resulted from differences in the magnitude, not direction, of the change in Antho concentrations among varieties with changes in T. This suggests that T was a main driver of Antho levels in this study. Regardless of V, Antho concentrations were highest, moderate and lowest after growth at 20 °C D/N, 30 °C/20 °C D/N and 30 °C D/N, respectively. Likewise, regardless of T, Antho levels followed the pattern `Impuls' (three genes) > `Valeria' (two genes) > `Lotto' (one gene). Correlations among instrumented and human eye-based evaluations of color are also being tested in samples from both studies.
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Gazula*, Aparna, Matthew D. Kleinhenz, Joseph C. Scheerens, Peter P. Ling, and John G. Streeter. "Variety and Planting Date Effects on Anthocyanin Concentrations in Field-grown Lettuce (Lactuca sativa)." HortScience 39, no. 4 (July 2004): 870D—870. http://dx.doi.org/10.21273/hortsci.39.4.870d.
Повний текст джерелаАнотація:
Anthocyanins (Antho) are the source of red color in plants and the intensity of redness is an important quality parameter in red leaf lettuce. Despite the importance of Antho in leaf lettuce, little information is available regarding the effects of major production-related factors, such as planting date, on their levels. To address this issue, field studies were conducted in 2002 and 2003 in which Antho levels were measured in nine lettuce varieties planted in early and late summer (ES and LS, respectively) using a RCB design. Leaf tissue was sampled 30 d after transplanting. Data for three strongly related Lolla Rossa-type varieties (`Lotto', `Valeria', `Impuls') are reported here. The planting date × variety interaction was significant; however, Antho concentrations were higher following planting in LS than ES, regardless of variety. Planting date effects were more pronounced in 2002, when differences in average daily temperature between ES and LS plantings tended to be larger. Regardless of planting date and year, Antho levels followed the pattern `Impuls' (three genes) > `Valeria' (two genes) > `Lotto' (one gene). Correlations between human visual and two types of instrumented assessments of color are being tested in samples from the same study.
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Jibril, Sani Ahmad, Siti Aishah Hassan, Che Fauziah Ishak, and Puteri Edaroyati Megat Wahab. "Cadmium Toxicity Affects Phytochemicals and Nutrient Elements Composition of Lettuce (Lactuca sativa L.)." Advances in Agriculture 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/1236830.
Повний текст джерелаАнотація:
Lettuce varieties Bombilasta BBL and Italian 167 were treated with different concentrations of cadmium (0, 3, 6, 9, and 12 mg/L) in a nutrient film technique (NFT) system to study its toxicity on phytochemicals and nutrient elements. Antioxidants analysis which employed DPPH and FRAP, flavonoids, phenolic, vitamin C, malondialdehyde (MDA), and proline indicated significant effects of Cd treatment on the varieties tested. Different concentration levels of Cd lead to positive interactions in FRAP, phenolic, and MDA but no significant effect in flavonoids, vitamin C, and proline. Contents of macro- and microelements in the varieties were significantly affected with increase in the toxicity levels of Cd in all nutrient elements tested with interactions exhibited for iron, manganese, and zinc.
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Yanti, G. F., and Ngadiani Ngadiani. "UJI BANDING BERBAGAI MEDIA TANAM TERHADAP PERTUMBUHAN SELADA MERAH (Lactuca sativa var. crispa L) DENGAN MEDIA TANAM HIDROPONIK SISTEM NFT (Nutrient Film Technique)." STIGMA: Jurnal Matematika dan Ilmu Pengetahuan Alam Unipa 11, no. 01 (May 14, 2018): 23–32. http://dx.doi.org/10.36456/stigma.vol11.no01.a1505.
Повний текст джерелаАнотація:
A study has been conducted to compare some varieties of planting media on red lettuce (Lactuca sativa var crispa L), the variables observed in this study are wet weight and chlorophyll content. This research was conducted by using complete randomized design (RAL) consisting of 5 variants of planting medium (Rockwool (as control), cocopeat, fuel husk, cotton and sponge) with 4 replications. The results showed that rockwool planting media had significant effect (P <0,05) on wet weight of red lettuce plant (Lactuca sativa var. Crispa L). Then, on the results of chlorophyll content test, it was found that the variation of burning husk medium media on red lettuce plant had significant effect (P <0,05) to chlorophyll a and total chlorophyll, while in chlorophyll b the result obtained was not significantly different (P> 0, 05). The results of this study indicate that the treatment of rockwool planting media in red lettuce plant growth is effective to increase wet weight and the treatment of burning husk medium media can increase the chlorophyll content of red lettuce plants namely chlorophyll a and total chlorophyll red lettuce plants (Lactuca sativa var. Crispa L.).
Keywords: red lettuce, wet weight, test of chlorophyll content a, chlorophyll b, total chlorophyll
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Kosyk, O. I., I. M. Khomenko, L. M. Batsmanova, and N. Yu Taran. "Phenylalanine ammonia-lyase activity and anthocyanin content in different varieties of lettuce under the cadmium influence." Ukrainian Biochemical Journal 89, no. 2 (April 24, 2017): 85–91. http://dx.doi.org/10.15407/ubj89.02.085.
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Roorda van Eysinga, J. P. N. L., and M. H. Cools. "CADMIUM IN BUTTERHEAD LETTUCE VARIETIES (LACTUCA SATIVA L., VAR. CAPITATA L.)." Acta Horticulturae, no. 222 (July 1988): 197–200. http://dx.doi.org/10.17660/actahortic.1988.222.24.
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Mampholo, Bevly M., Martin Maboko, Puffy Soundy, and Dharini Sivakumar. "Postharvest responses of hydroponically grown lettuce varieties to nitrogen application rate." Journal of Integrative Agriculture 18, no. 10 (October 2019): 2272–83. http://dx.doi.org/10.1016/s2095-3119(19)62664-x.
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Ismawati, Dwi, Tri Rahayu, and Srie Juli Rachmawatie. "Pengaruh Dosis Pupuk Kandang Ayam terhadap Pertumbuhan dan Hasil Tiga Macam Varietas Selada (Lactuca sativa L.)." Daun: Jurnal Ilmiah Pertanian dan Kehutanan 8, no. 1 (June 30, 2021): 10–18. http://dx.doi.org/10.33084/daun.v8i1.2173.
Повний текст джерелаАнотація:
The study aims to determine the influence of chicken manure dose on growth and yield on three kinds of lettuce (Lactuca sativa, L.) planted in a polybag. This research was conducted from November 2019 until January 2020, in Gerdu Village, Karangpandan District, Karanganyar Regency, between 450 - 650 m above sea level. The research used a factorial method with a Completely Randomized Design (CRD) consist of two treatment factors. The first factor is dose of chicken manure consisting of 3 levels (D1 = 62.5 g/ polybag, D2 = 125 g / polybag, D3 = 187.5 g/ polybag). The second factor was varieties of lettuce (V) consist of 3 types (V1 = Grand Rapids Variety, V2 = Kriebo Variety, V3 = Bisi SL 02 Variety). Analysis of variance was used to analyzed the data, with the F test at 5% and 1% levels and then followed by Duncan's multiple range test at 5% level. The results showed that chicken manure dosage significantly affects fresh weight and consumption weight per plant. The best dose of chicken manure for the treatment is 125 g / polybag. The varieties significantly affected plant height, fresh weight, and consumption weight and significantly affected leaf width per plant. The interaction between the dose of chicken manure and varieties of lettuce (DxV) showed the best results on the combination 125 g / polybag chicken manure dose with the Kriebo variety (D2V2). This treatment combination gives the highest consumption weight, which is 76.52 g. While the treatment combination of 62.5 g / polybag chicken manure dose and Bisi SL 02 variety (D1V3) had the lowest consumption weight (39.68 g).
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Corrado, Giandomenico, Luigi Lucini, Begoña Miras-Moreno, Leilei Zhang, Christophe El-Nakhel, Giuseppe Colla, and Youssef Rouphael. "Intraspecific Variability Largely Affects the Leaf Metabolomics Response to Isosmotic Macrocation Variations in Two Divergent Lettuce (Lactuca sativa L.) Varieties." Plants 10, no. 1 (January 5, 2021): 91. http://dx.doi.org/10.3390/plants10010091.
Повний текст джерелаАнотація:
Mineral elements are essential for plant growth and development and strongly affect crop yield and quality. To cope with an everchanging environment, plants have developed specific responses to combined nutrient variations. In this work, we investigated the effects of multifactorial treatments with three macrocations (K, Ca, and Mg) on lettuce (Lactuca sativa L.) varieties that strongly diverge in leaf pigmentation (full red or green). Specifically, we monitored main leaf parameters and metabolomics profiles of hydroponically grown plants fed with isosmotic nutrient solutions that have different proportions of macroelements. The result revealed a high biochemical plasticity of lettuce, significantly affected by the genotype, the nutrient solution, and their interaction. Our work also provided evidence and insights into the different intraspecific responses to multifactorial variation of macrocations, with two varieties having distinct strategies to metabolically respond to nutrient variation. Overall, plant adaptive mechanisms increased the phytochemical diversity between the varieties both among and within the main classes of plant secondary metabolites. Finally, our work also implies that the interaction of a pre-existing phytochemical diversity with the management of multiple mineral elements can offer added health-related benefits to the edible product specific to the variety.
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Eriksen, Renée L., Caleb Knepper, Michael D. Cahn, and Beiquan Mou. "Screening of Lettuce Germplasm for Agronomic Traits under Low Water Conditions." HortScience 51, no. 6 (June 2016): 669–79. http://dx.doi.org/10.21273/hortsci.51.6.669.
Повний текст джерелаАнотація:
After a preliminary screening of over 3500 cultivars, we selected 200 butterhead, cos, crisphead, leaf, and stem lettuce (Lactuca sativa L.) and wild prickly lettuce (Lactuca serriola L.) varieties to test under high water (150% evapotranspiration [ET]) and low water (50% ET) conditions in the field, and tracked commercially relevant traits related to growth and marketability, maturity, and physiology. Plants typically reduced growth and appeared to reallocate developmental resources to achieve maturity quickly, as indicated by traits such as increased core length. This strategy may allow them to complete their life cycle before severe drought stress proves lethal. Although most cultivars experienced a reduction in growth under low water conditions relative to high water conditions, some cultivars had a significantly reduced yield penalty under stress conditions. Among the different types of lettuce, the fresh weight (FW) of cos cultivars was most affected by drought stress, and the FW of leaf lettuce was least affected. Cos cultivars tended to bolt early. Crisphead cultivars Cal-West 80, Heatmaster, and Marion produced large heads and did not bolt under low water treatments, and butterhead cultivars Buttercrunch and Bibb also produced relatively large heads with very little bolting and no signs of tipburn. The four green leaf cultivars Slobolt, Grand Rapids, Western Green, and Australian showed no statistically significant difference in FW among high and low water treatments in multiple trials, and may be good choices for growers who wish to minimize losses under reduced irrigation. The identification of potentially drought-tolerant varieties and the information from this study may be helpful for cultivar selection by growers under drought conditions, but this study also serves as a step forward in the genetic improvement of lettuce to drought stress.
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Kamalia, Siti, Parawita Dewanti, and Raden Soedradjad. "TEKNOLOGI HIDROPONIK SISTEM SUMBU PADA PRODUKSI SELADA LOLLO ROSSA (Lactuca sativa L.) DENGAN PENAMBAHAN CaCl2 SEBAGAI NUTRISI HIDROPONIK." JURNAL AGROTEKNOLOGI 11, no. 1 (October 2, 2017): 96. http://dx.doi.org/10.19184/j-agt.v11i1.5451.
Повний текст джерелаАнотація:
Calcium in one of the important minerals that are needed by human body as much as 1200 mg calciums/ day/ person. Every day humans consume calcium as much as 254 mg/ day/ person and it causes people suffering ostheoporosis and other growth disorders. Therefore human needs to consume the source of calcium, one of them is vegetables. Vegetables in one of the source of calcium that is cheap, obtainable and consumable. Lettuce (Lactuca sativa L.) is one of the vegetable with high caclsium but development of lettuce cultivation is still limited.. The efford to increase the quantity and quality of lettuce production can be done with hydroponics technology. Hydroponics technology enables efficient lettuce cultivation. The innovation adding of CaCl2 concentration in hydroponic nutrients is expected to increase the lettuce production. The purpose of this research was to determine the concentration of CaCl2 on the hydroponic nutrients of wick system on the production of Lollo Rossa lettuce (Lactuca sativa L.). The research was conducted at the Green House, Faculty of Agriculture, University of Jember, started in August to Noverber 2016. The research used Completely Randomized Design (CRD) with single factor, which was concentration of CaCl2 on the hydroponic nutrients (C) and it be combined with Lollo Rossa varieties of lettuce (Lactuca sativa L.) (S) with three replications. The best concentration of CaCl2 for Lollo Rossa production was 650 ppm.
Keywords: Lettuce, hydroponic, calcium, CaCl2
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Xu, Chenping, and Beiquan Mou. "Evaluation of Lettuce Genotypes for Salinity Tolerance." HortScience 50, no. 10 (October 2015): 1441–46. http://dx.doi.org/10.21273/hortsci.50.10.1441.
Повний текст джерелаАнотація:
Lettuce is one of the most commonly used salad vegetables and considered to be a relatively salt-sensitive crop. Salinity is a major constraint to crop production in all important lettuce growing regions of the United States, and the water quality problem is exacerbated by climate change. To identify salt-tolerant lettuce genotypes, 178 cultivars and germplasm accessions (56 butterhead, 39 crisphead, 35 romaine, 33 leaf, and 15 wild types) were selected from a preliminary screening of more than 3800 genotypes, and tested for salinity tolerance in sand cultures under greenhouse conditions. Plants were grown in Hoagland nutrient solution, either with or without 30/15 mm NaCl/CaCl2, and leaf fresh and dry mass (FM and DM), chlorophyll index, and maximal photochemical efficiency (Fv/Fm) were measured 4 weeks after plants were transplanted. Generally, salinity decreased lettuce shoot FM and DM, increased DM/FM ratio and chlorophyll index, and had no effect on Fv/Fm. Some lettuce varieties showed salt tolerance (less than 15% reduction in FM), such as PI 342515, PI 358020c, ‘Morgana’, ‘Amerika’ (butterhead), ‘Laura’ (crisphead), PI 289023, PI 273577, PI 278066, PI 177425 (romaine), PI 171676a, PI 177423, PI 342477, and PI 358018b (leaf). The results indicate that lettuce genotypes differ greatly in their salt sensitivity, which could be useful for growers to choose cultivars and for breeders to improve lettuce adaptation to salinity stress.
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Corrado, Giandomenico, Paola Vitaglione, Georgios A. Soteriou, Marios C. Kyriacou, and Youssef Rouphael. "Configuration by Osmotic Eustress Agents of the Morphometric Characteristics and the Polyphenolic Content of Differently Pigmented Baby Lettuce Varieties in Two Successive Harvests." Horticulturae 7, no. 9 (August 25, 2021): 264. http://dx.doi.org/10.3390/horticulturae7090264.
Повний текст джерелаАнотація:
Salinity eustress is one of the pre-harvest factors that can be used to improve the phytochemical profile and the quality attributes of horticultural species, and most of the studies are carried out using NaCl. In this work, we compared the effect of three mildly saline iso-osmotic nutrient solutions (NS) differing in the cation employed (either K, Na, or Ca) in baby lettuce cultivated in a floating system. Specifically, we analyzed the impact on key morphological traits and polyphenol composition in leaves in a completely randomized design experiment with the following experimental factors and levels: two differently pigmented lettuce varieties (green and full red), three NSs (20 mM KCl, 20 mM NaCl, 13.3 mM CaCl2, each with a final ionic concentration of 40 mM), and two successive harvests. The lettuce response to mild salinity was multifaceted and with a marked role for the cultivar factor and its interactions, as also indicated by multivariate analysis. The morphological response of baby lettuce to the saline solutions was predominantly affected by the osmolarity, and ion-specific alleviating or detrimental effects were not observed. The phytochemical analysis revealed significant interactions among all tested factors, with ion-specific differences over some of the detected phenolics. This is consistent with the high sensitivity of this class of bioactive compounds to environmental factors. This work indicated that certain combinations of the experimental factors tested can be exploited to improve the biochemical profile and possibly the nutraceutical quality of baby lettuce in a floating system.
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Fenoll, Jose, Pilar Hellin, Josefa Lopez, Alberto Gonzalez, and Pilar Flores. "Determination of Pesticide Residues in Lettuce by Gas Chromatography with Electron-Capture Detection." Journal of AOAC INTERNATIONAL 90, no. 6 (November 1, 2007): 1670–76. http://dx.doi.org/10.1093/jaoac/90.6.1670.
Повний текст джерелаАнотація:
Abstract A sensitive, rapid, and simple multiresidue method for the simultaneous determination of 19 pesticides in different varieties of lettuce (Lactuca sativum) was developed. Lettuce samples were extracted by homogenization with acetone and partitioned into ethyl acetatecyclohexane. Subsequent sample cleanup was not needed. Final determination was made by capillary gas chromatography (GC) with electron-capture detection (ECD). Confirmation analysis of pesticides was performed by GC coupled with mass spectrometry in the selected ion monitoring mode. The average recovery by the GCECD method obtained for these compounds varied from 66.4 to 119.2 with relative standard deviations <7.7. The GCECD method has good linearity, and the detection limit for the pesticides studied varied from 0.1 to 3.8 g/kg. The proposed method was used to determine pesticide levels in different types of lettuce grown in soils from experimental fields.