Готові списки джерел за темами / Lettuce varieties

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Добірка наукової літератури з теми "Lettuce varieties"

Автор: Grafiati

Опубліковано: 4 червня 2021

Оновлено: 1 лютого 2022

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Статті в журналах з теми "Lettuce varieties"

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.

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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

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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.

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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.

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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.

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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)

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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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Більше джерел

Дисертації з теми "Lettuce varieties"

Rethwisch, Michael D., Marvin D. Butler, and Mike Meadows. "Evaluation of Head Lettuce Varieties for Liriomyza trifolii Leafminer Populations." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/214266.

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Zerkoune, Mohammed A. "Field Evaluation of Romaine Lettuce Varieties Grown in Southwest Low Desert Soils." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/214934.

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Romaine lettuce plays an important role in Yuma’s economy. An estimated 10,000 acres are cropped to large number of varieties each year with planting season that spreads from September to March. The demonstration site was selected to compare new and existing varieties of romaine lettuce on growers’ fields using standard farming practices. Selected growth parameters were evaluated throughout the growing season. Results indicate that varieties tested at Barkley Farms in Yuma are expected to do well if grown under similar growing conditions and planting time. Varieties tested during this planting slot did not experience any incidence of diseases. There was no significant head size and head weight difference among varieties evaluated. Number of heads per bed and number of heads left after harvest were significantly different among varieties tested.

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Zerkoune, Mohammed A. "Field Evaluation of Crisp-head Lettuce Varieties Grown in Southwest Low Desert Soils." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/220393.

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Crisp-head lettuce plays an important role in Yuma’s economy. An estimated 51000 acres are cropped to large number of varieties each year with planting season that spreads from late August to March. Three demonstration sites and three planting dates were selected to compare new and existing varieties of head lettuce on growers’ fields using standard farming practices. Selected growth parameters were evaluated throughout the growing season. Results indicate that varieties tested at JV Farms in Welton and at Yuma Agricultural Center (YAC) are expected to do well if grown under similar conditions and planting time. Some varieties tested during the second planting slot on Doug Melon Farm experienced some incidence of diseases. All three planting sites showed a significant head weight difference and two out of three planting sites showed a significant head diameter difference.

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Orruel, Fusco Francisco Javier. "Agronomic performance of two baby lettuce varieties (Lactuca sativa L.) at three planting densities using panqar huyus in the Ingavi province." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/5412.

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This study was conducted in the experimental unit of the Benson Agriculture and Food Institute, which is located in the Letanias community of the Ingavi province in the department of La Paz. Our objective was to compare the agronomic performance of two baby lettuce varieties (Lactuca sativa L.) at three planting densities in panqar huyus. In order to provide the rural farmer communities of Contorno Letanias and Contorno Medio a possible cost-effective alternative and to employ the use of moderate environments called panqar huyus, we introduced two varieties of baby lettuce: 1) Little Gem in seed form and 2) Tom Thumb already sprouted. These two were planted at densities of 250,000, 333,333, and 500,000 plants/hectare. Statistical analyses performed using the F-test and Duncan’s Multiple Range test found statistical differences between the varieties of baby lettuce and/or planting densities in the following response variables: plant height, number of leaves, root length, total foliage area, green foliage yield, and individual weight of green foliage. The values we obtained for green foliage yield were below those published by the European Union (2004). This was mainly due to the climate of the interior of the panqar huyus. The highest average yield achieved by the baby lettuce varieties was reached by Little gem in seed form with a value of 1.66 kg/m2. As for the planting densities, the highest yield was obtained with the 500,000 plants/hectare density, which had a value of 2.18 kg/m2. As for the quality of the harvested product, the values closest to the parameters established by the European Nations (2004) and the MAG/IICA (2004) were obtained in treatments 5 and 6. Some of these parameters were head diameter, plant height, number of leaves, total foliage area, and individual weight of green foliage. Furthermore, the economic analysis done via the partial budget estimate proposed by CIMMYT (1983) determined that treatment 5 (Little gem in seed form planted at a planting density of 500,000 plants/hectare) is the most profitable when compared to the other treatments in the area of domain.

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Книги з теми "Lettuce varieties"

Hill, David E. Romaine and looseleaf lettuce trials, 1996-1997. New Haven: Connecticut Agricultural Experiment Station, 1999.

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Hill, David E. Romaine and looseleaf lettuce trials, 1996-1997. New Haven: Connecticut Agricultural Experiment Station, 1999.

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Agricultural Development and Advisory Service., ed. Lettuce varieties for protected cropping. Alnwick: Ministry of Agriculture, Fisheries and Food, 1986.

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Тези доповідей конференцій з теми "Lettuce varieties"

Laratta, Bruna, Filomena Monica Vella, Roberto Calandrelli, and Domenico Cautela. "Screening of Bioactivity in Extracts from Different Varieties of Lettuce." In The 1st International Electronic Conference on Plant Science. Basel, Switzerland: MDPI, 2020. http://dx.doi.org/10.3390/iecps2020-08755.

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