scholarly journals SPECTRAL CHARACTERISTICS OF CELERY CULTIVARS' LEAF TISSUES

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 248a-248
Author(s):  
Nicolas Tremblay ◽  
Yvon Perron
Keyword(s):  
Discriminant Function ◽  
Growth Stage ◽  
Spectral Characteristics ◽  
Nutrient Status ◽  
Growth Chamber ◽  
Nutrient Deficiencies ◽  
Spectral Variability ◽  
Promising Tool ◽  
Leaf Tissues ◽  
Fertility Problems

As plant color is often modified by nutrient status, the use of spectoradiometric properties of leaf tissues appears to be a promising tool for quick and inexpensive diagnosis of crop fertility problems. This study was conducted to examine spectral variability associated with celery cultivars. Seedlings of Florida 683, Matador, Utah 5270, and Ventura were grown in a growth chamber for 10 weeks (transplant stage; TS). Reflectance and transmittance measurements were taken on the tallest leaf with a LI-COR LI-1800 spectroradiometer. Remaining seedlings were potted and transferred to a greenhouse for another 8 weeks (mid-growth stage; MS). Transmittance was established as the parameter most suitable to distinguish cultivars. Maximum F ratio was obtained at λ = 630 mn at TS, while there were two peeks (λ = 470 and 60 mn) at MS. A discriminant function was based on λ = 470; 630 and 670 mn correctly classified cultivars more than 8 times out of 10 at TS, and more than 7 times out of 10 at MS. Further studies should focus on the induction of nutrient deficiencies and the potential interferences of cultivars with their diagnosis.

scholarly journals A NUTRITIONAL MANAGEMENT SYSTEM FOR TROPICAL FRUIT AND NUT ORCHARDS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 669d-669
Author(s):  
H.H. Hirae ◽  
M.A. Nagao
Keyword(s):  
Management System ◽  
Leaf Tissue ◽  
Nutrient Status ◽  
Tree Age ◽  
Nutritional Management ◽  
Nutrient Deficiencies ◽  
Tropical Fruit ◽  
Extension Agent ◽  
Fertilizer Recommendations ◽  
Macadamia Nut

Monitoring the nutrient status of a crop by soil and tissue analysis is an important tool in maximizing yields and avoiding nutrient deficiencies or toxicities. A nutritional management system is presented that uses a computer database to compile periodic soil and leaf tissue analyses to assist in the development of rational fertilizer recommendations for banana and macadamia nut orchards. Database management allows the Extension Agent to organize parameters (soil type, rainfall, elevation, tree age, tree spacing, and previous fertilizer practices) used in nutritional recommendations for individual farms. Graphs depicting nutrient trends over time and comparison of nutrient levels to nutritional standards, present visual illustrations of problems and encourage grower acceptance of fertilizer recommendations. Growers are also able to see graphic responses to application of corrective fertilizers and soil amendments.

scholarly journals Monthly Monitoring of the Nutrient Status in Citrus Leaves as a Guide for Proper Fertilization

1999 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
A.A. EI-Sayed ◽  
M.M. Shaaban
Keyword(s):  
Growth Stage ◽  
Clay Soil ◽  
Nutrient Status ◽  
Leaf Nitrogen ◽  
Nutrient Concentrations ◽  
Soil Conditions ◽  
Split Application ◽  
Growing Seasons ◽  
Nitrogen Concentrations ◽  
Citrus Leaves

A field study was conducted with five citrus cultivars grown in clay soil in Kewesna, Monufia, Egypt for two successive growing seasons. The study aimed at using nutrient concentrations in the leaves as a guide for proper fertilization. The study revealed that most of the nutrients in the soil were at adequate levels. However, there were unfavorable soil conditions that affected negatively nutrient availability, Nutrient concentrations in the leaves of the five cultivars were nearly the same, except for a few cases. Leaf nitrogen concentrations were at adequate levels. To minimize the usage of fertilizers, the quantity of N-fertilizer should not exceed 100 kg N per feddan, added as three doses in September, March and June. Phosphorus fertilizers should be added in September and when another dose is needed, it should be in May. For such a clay soil, nearly double the potassium requirement of the crop should be added as split application. More attention should be given to magnesium fertilization. Micronutrients concentrations were at adequate levels. However, under such soil conditions, fertilizers of acidic reactions are recommended and micronutrients should be supplied as foliar sprays in September, March and May. Adequate levels of the nutrients in the 5-7 months spring flush together with the high obtained yields suggest that the obtained levels of the nutrients (except copper) can be used as a basis to correct the fertilizer programmes at any growth stage.

scholarly journals Selenization of Basil and Cilantro Through Foliar Applications of Selenate-selenium and Selenite-selenium

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 438-442 ◽  
Author(s):  
Dean A. Kopsell ◽  
Carl E. Sams ◽  
T. Casey Barickman ◽  
Dennis E. Deyton ◽  
David E. Kopsell
Keyword(s):  
Leaf Tissue ◽  
Dry Weight ◽  
Growth Chamber ◽  
Crop Species ◽  
Field Environment ◽  
Leaf Tissues ◽  
Edible Tissues ◽  
High Concentrations ◽  
Daily Intakes ◽  
Alternative Delivery

Selenium (Se) is an essential mammalian micronutrient. Adult humans have a daily requirement of 55 to 70 μg/day Se depending on sex and pregnancy/lactation for females. In addition, recent studies have shown health benefits with dietary Se supplementation of 100 to 200 μg/day Se. However, daily intakes in humans greater than 900 μg Se will result in toxicity called selenosis. Although not essential in plant nutrition, some species can bioaccumulate Se. Brassica and Allium species became prime candidates for Se enrichment because of their ability to accumulate and tolerate high concentrations of Se in edible tissues; however, there is now concern that these species are too efficient at selenization and overconsumption of their selenized tissues could result in selenosis. Herbal crop species are consumed regularly in the diet for their culinary flavor attributes. Basil (Ocimum basilicum L.) and cilantro (Coridandrum sativum L.) are not classified as Se accumulators. Therefore, a study was undertaken to determine the potential to selenize basil and cilantro through foliar Se applications to consistently supplement diets with nutritionally beneficial levels of Se. Plants of each species were grown in both growth chamber and field environments and treated with foliar applications (5 mL per plant) of selenate-Se and selenite-Se at concentrations of 0, 2, 4, 8, 16, and 32 mg·L−1 Se. Crops received three separate foliar applications at ≈5-day intervals beginning 24 to 28 days after planting for the growth chamber plants and 50 days after planning for the field environment. Selenium accumulation in both basil and cilantro leaf tissues increased linearly under both selenate-Se (P ≤ 0.001) and selenite-Se (P ≤ 0.001) foliar treatments in growth chamber and field evaluations. Maximum Se leaf tissue concentrations for basil and cilantro ranged from 13 to 55 μg·g−1 Se dry weight. Selenization of basil and cilantro is possible through foliar Se applications, and Se fortification of herbal crops may provide alternative delivery systems in human diets.

Developmental and Environmental Effects on Assimilate Partitioning in Canada Thistle (Cirsium arvense)

Weed Science ◽  
1992 ◽  
Vol 40 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Thomas Tworkoski
Keyword(s):  
Environmental Effects ◽  
Environmental Conditions ◽  
Growth Stage ◽  
Early Spring ◽  
Field Conditions ◽  
Cirsium Arvense ◽  
Growth Chamber ◽  
Assimilate Partitioning ◽  
Canada Thistle ◽  
Flower Bud

Under field conditions, more photoassimilate moved to roots of Canada thistle at the bolt than at the bud, flower, or postflower stages. Similarly, greater photoassimilate accumulated in roots of Canada thistle in the greenhouse at the rosette and bolt than at the flower bud stage. Growth chamber experiments indicated that environmental conditions typical of fall, and possibly early spring, favored photoassimilate movement to the root and superseded growth stage control of assimilate partitioning. Allocation of assimilate within the root was strongly influenced by growth stage, with most assimilate being utilized for growth at the rosette stage and for fructan reserves in bolt and flower bud stages.

Variability in /s/ Production in Children and Adults

2004 ◽  
Vol 47 (1) ◽  
pp. 58-69 ◽  
Author(s):  
Benjamin Munson
Keyword(s):  
Temporal Variability ◽  
Spectral Characteristics ◽  
Age Groups ◽  
Developmental Differences ◽  
Spectral Variability ◽  
Place Of Articulation ◽  
Phonetic Context

Previous research has found developmental decreases in temporal variability in speech. Relatively less work has examined spectral variability, and, in particular, variability in consonant spectra. This article examined variability in productions of the consonant /s/ by adults and by 3 groups of children, with mean ages of 3;11 (years;months), 5;04, and 8;04. Specifically, it measured the influence of age, phonetic context, and syllabic context on variability. Spectral variability was estimated by measuring dynamic spectral characteristics of multiple productions of /s/ in sV, spV, and swV sequences, where the vowel was either /a/ or /u/. Mean duration, variability in duration, and coarticulation were also measured. Children were found to produce /s/ with greater temporal and spectral variability than adults. Duration and coarticulation were comparable across the 4 age groups. Spectral variability was greater in swV contexts than in sV or spV sequences. The lack of consistent effects of phonetic context on spectral variability suggests that the developmental differences were related to subtle variability in place of articulation for /s/ in the children's productions.

scholarly journals The Potential of Multi- and HyperSpectral Air- and Spaceborne Sensors to Detect Crude Oil Hydrocarbon in Soils Long after a Contamination Event

2019 ◽  
Vol 9 (23) ◽  
pp. 5151 ◽  
Author(s):  
Ran Pelta ◽  
Eyal Ben-Dor
Keyword(s):  
Crude Oil ◽  
Hyperspectral Image ◽  
Spectral Characteristics ◽  
Spectral Features ◽  
Basic Premise ◽  
Promising Tool ◽  
Quality Classification ◽  
Spatial Configurations ◽  
Contamination Event ◽  
Original Size

Crude oil contamination is hazardous to health, negatively impacts vital life sources, and causes land and ecological degradation. The basic premise of the prevalent spectroscopic analyses for detecting such contamination is that crude oil spectral features are observable in the spectrum. Such analyses, however, have failed to address instances where the expected spectral features are not visible in the spectrum. Hence, a more refined method was recently published, which accounts for such cases. This method was successfully applied to a hyperspectral image over an arid area long after a contamination event. This study aimed to determine whether that same method could be successfully applied using a variety of other operational and future instruments, both air- and spaceborne, with different spatial and spectral characteristics. To that end, a series of simulation experiments was performed, including various spectral and spatial resolutions. Quantitative and qualitative evaluations of the classification are reported. The results indicate that the hyperspectral information can be reduced to one-third of its original size, while maintaining high accuracy and a quality classification map. A ground sampling distance of 7.5 m seems to be the boundary of an acceptable classification outcome. The overall conclusion of this study was that the method is robust enough to perform under various spectral and spatial configurations. Therefore, it could be a promising tool to be integrated into environmental protection and resource management programs.

RELATION OF NUTRIENT CONTENT OF RUTABAGA LEAVES TO FERTILIZATION WITH N, P, AND K

1974 ◽  
Vol 54 (1) ◽  
pp. 135-139
Author(s):  
D. C. MUNRO ◽  
J. A. CUTCLIFFE
Keyword(s):  
Leaf Tissue ◽  
Nutrient Content ◽  
Nutrient Deficiencies ◽  
Harvest Time ◽  
Factorial Experiments ◽  
Total N ◽  
Mature Leaves ◽  
Nutrient Levels ◽  
Leaf Tissues ◽  
Four Levels

Rutabagas (Brassica napobrassica Mill., cult York) were grown at three locations per year for 3 yr in factorial experiments of four levels of N, P, and K. Uppermost mature leaves were sampled at the beginning of root enlargement, at harvest time, and once between these dates. The leaf tissue was dried, ground, and analyzed for total N, P, and K. Percent N in leaf tissue was substantially increased by applied N, increased by applied P at some locations, and decreased by applied K. Percent P was increased by applied P and somewhat by applied N but decreased by applied K. Applied K increased the K content of leaf tissues but applied P and N caused substantial decreases in tissue K. Tissue N, P, and K decreased as the crop matured. To prevent nutrient deficiencies, rutabaga leaf-tissue at the beginning of root enlargement must contain at least 4.1% N, 0.46% P, and 2.0% K. Optimum nutrient levels for good yields are in the ranges 5.4–5.9% N, 0.58–0.70% P, and 3.0–3.8% K at this stage of growth.

scholarly journals Undernutrition, infection and immune function

2000 ◽  
Vol 13 (1) ◽  
pp. 3-29 ◽  
Author(s):  
Philip C. Calder ◽  
Alan A. Jackson
Keyword(s):  
Infectious Diseases ◽  
Immune Function ◽  
Maternal Education ◽  
Nutrient Status ◽  
Diarrhoeal Disease ◽  
The Body ◽  
Morbidity And Mortality ◽  
Nutrient Deficiencies ◽  
Quality Water ◽  
Tract Infections

AbstractUndernutrition and infection are the major causes of morbidity and mortality in the developing world. These two problems are interrelated. Undernutrition compromises barrier function, allowing easier access by pathogens, and compromises immune function, decreasing the ability of the host to eliminate pathogens once they enter the body. Thus, malnutrition predisposes to infections. Infections can alter nutritional status mediated by changes in dietary intake, absorption and nutrient requirements and losses of endogenous nutrients. Thus, the presence of infections can contribute to the malnourished state. The global burden of malnutrition and infectious disease is immense, especially amongst children. Childhood infections impair growth and development. There is a role for breast-feeding in protection against infections. Key nutrients required for an efficient immune response include vitamin A, Fe, Zn and Cu. There is some evidence that provision of the first three of these nutrients does improve immune function in undernourished children and can reduce the morbidity and mortality of some infectious diseases including measles, diarrhoeal disease and upper and lower respiratory tract infections. Not all studies, however, show benefit of single nutrient supplementation and this might be because the subjects studied have multiple nutrient deficiencies. The situation regarding Fe supplementation is particularly complex. In addition to immunization programmes and improvement of nutrient status, there are important roles for maternal education, improved hygiene and sanitation and increased supply of quality water in the eradication of infectious diseases.

COMPARISON OF MAIZE (Zea mays L.) GROWTH AND NITROGEN PARAMETERS UNDER HYDROPONIC AND FIELD CONDITIONS

1989 ◽  
Vol 69 (3) ◽  
pp. 643-651
Author(s):  
R. T. WEILAND ◽  
A. M. McCLUNG
Keyword(s):  
Zea Mays ◽  
Growth Stage ◽  
Zea Mays L ◽  
Field Conditions ◽  
Growth Chamber ◽  
Shoot Biomass ◽  
Dry Matter Accumulation ◽  
Total N ◽  
Chamber Studies ◽  
Growth Chamber Studies

A comparison of biomass and nitrogen (N) parameters from 23 maize (Zea mays L.) inbreds was conducted between hydroponic culturing during two growth chamber studies and soil in the field for two harvests during 1984. The growth chamber studies and first field harvests were sampled at a similar growth stage (approximately nine-leaf); the second field harvest was at anthesis. Shoot dry matter accumulation was greater under hydroponic than under field conditions at a similar vegetative growth stage. Significant inbred differences for shoot biomass, reduced and total N contents and reduced and total N concentrations were determined for the growth chamber and both field harvests. Correlation coefficients were low and not significant (P < 0.05) between inbred parameters in the growth chamber and in the field. In summary, traits from hydroponic plants were not predictive of those from field plants. However, N parameters and biomass of inbreds harvested in the field at a mid-vegetative stage were predictive of inbred performance at anthesis.Key words: Zea mays L., maize, biomass, nitrogen, field, hydroponic

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