Tuesday, November 17, 2009
A multi-angle spectrometer for automatic measurement of plant canopy reflectance spectra
The paper describes the design and operation of a multi-angle spectrometer (MAS) for automatic measurement of near-field spectral reflectances of plant canopies at hourly intervals. A novel feature of the instrument is a rotating periscope connected to a spectrometer via a fiber optic cable. Canopy reflectances are calculated for multiple view azimuths, at a single zenith angle from measurements of spectrometer dark current, incoming solar irradiance and reflected radiances. Spectral measurements are made between 300 and 1150 nm wavelength at a band-to-band spacing of 3 nm, and a bandwidth (full-width, half maximum) of 10 nm. Preliminary data analysis showed that the canopy reflectance model of Kuusk [Kuusk, A. (1995). A fast, invertible canopy reflectance model. Remote Sensing of Environment 51, 342–350] reproduced the observed large differences in visible and near-infrared (NIR) reflectances, but the model was unable to predict quantitatively the observed variations in the measured reflectance spectra with azimuth, particularly in the NIR. Discrepancies between model and measurements are likely due to the inhomogeneous nature of the forest canopy in contrast to the assumption of a uniformly absorbing turbid medium in the model. Measurements using the MAS can be used to investigate directional dependences of reflectance indices and for testing BRDF models used to separate geometrical and plant physiological contributions to the reflectance signals. The MAS provides continuous sampling of reflectance indices which can be compared with canopy properties such as chlorophyll content and photosynthetic capacity.
Thursday, November 12, 2009
NIR spectroscopy for plant nutrient analysis underwater and in the trees
he enormous variability in the concentration of plant toxins and nutrients in trees, shrubs and forbs requires extensive sampling to accurately represent the nutritional and toxicological landscape and this is an ideal application for quantitative near infrared (NIR) reflectance spectroscopy. The speed of NIR spectroscopy analysis makes it ideally suited to environmental monitoring and ecological investigations where large numbers of replicates need to be measured. Several recent studies, including one focused on underwater plants on the Great Barrier Reef and the second in Bolivian rainforests, show the power of NIR spectroscopy to address large-scale variability in plant–animal interactions.
Dugongs are large (200 kg) marine herbivores that feed mostly on seagrass. Seagrasses are monocotyledonous plants that grow in the intertidal zone but also at depths of up to 30 m. Large herds of dugongs can congregate on seagrass meadows and make repeated, short dives where they graze the leaves of the seagrasses or even uproot and eat the whole plant. We were interested in whether grazing by dugongs improved the quality of the re-growth—in other words, were they able to “farm” seagrass meadows to maintain quality? Using NIR spectroscopy to analyse nutritional components in about 1200 seagrass samples showed that this was indeed the case.1 Grazing by dugongs improved the nutritional quality of meadows significantly. Many other species use seagrass meadows and regular grazing by dugongs is likely to have effects on the whole community of seagrass-dependent species.
A second study sought to understand the impact on logging on populations of black spider monkeys in Bolivian rainforests.2 Annika Felton followed black spider monkeys, observed their food choices and either retrieved freshly dropped fruit and leaves or else climbed to the canopy to retrieve it. Because it was so important to analyse exactly the parts that the monkeys were eating, in many cases, we only had a small amount of material. Fortunately, we were able to develop robust NIR spectroscopy calibration equations to predict the chemical composition and in particular the amount of protein that was available to the monkeys. Annika found that spider monkeys aimed for a target amount of protein each day, regardless of whether they only ate ripe fruit or mixed in other vegetable matter as well and she was able to recommend a selective logging regime that preserved the most important resources in the forest.
Although rainforest logging can be highly destructive for tree dwelling mammals, this story had a happy ending. During the study, Annika and her husband Adam discovered a new species of titi monkey and, in conjunction with the Wildlife Conservation Society, auctioned the naming rights to raise funds ($US650,000) to employ park rangers in perpetuity. The animal is now known as the Golden Palace monkey3 (Callicebus aureipalatii) after the Golden Palace (online) Casino!
Dugongs are large (200 kg) marine herbivores that feed mostly on seagrass. Seagrasses are monocotyledonous plants that grow in the intertidal zone but also at depths of up to 30 m. Large herds of dugongs can congregate on seagrass meadows and make repeated, short dives where they graze the leaves of the seagrasses or even uproot and eat the whole plant. We were interested in whether grazing by dugongs improved the quality of the re-growth—in other words, were they able to “farm” seagrass meadows to maintain quality? Using NIR spectroscopy to analyse nutritional components in about 1200 seagrass samples showed that this was indeed the case.1 Grazing by dugongs improved the nutritional quality of meadows significantly. Many other species use seagrass meadows and regular grazing by dugongs is likely to have effects on the whole community of seagrass-dependent species.
A second study sought to understand the impact on logging on populations of black spider monkeys in Bolivian rainforests.2 Annika Felton followed black spider monkeys, observed their food choices and either retrieved freshly dropped fruit and leaves or else climbed to the canopy to retrieve it. Because it was so important to analyse exactly the parts that the monkeys were eating, in many cases, we only had a small amount of material. Fortunately, we were able to develop robust NIR spectroscopy calibration equations to predict the chemical composition and in particular the amount of protein that was available to the monkeys. Annika found that spider monkeys aimed for a target amount of protein each day, regardless of whether they only ate ripe fruit or mixed in other vegetable matter as well and she was able to recommend a selective logging regime that preserved the most important resources in the forest.
Although rainforest logging can be highly destructive for tree dwelling mammals, this story had a happy ending. During the study, Annika and her husband Adam discovered a new species of titi monkey and, in conjunction with the Wildlife Conservation Society, auctioned the naming rights to raise funds ($US650,000) to employ park rangers in perpetuity. The animal is now known as the Golden Palace monkey3 (Callicebus aureipalatii) after the Golden Palace (online) Casino!
Wednesday, November 11, 2009
Detecting disease in greenhouse plants
Greenhouses are an integral part of U.S. agriculture. Nearly $200 million of food is produced in domestic greenhouses each year, and the facilities play a vital role in producing seeds and transplantable vegetation. Understanding how to keep greenhouse plants healthy can translate to increased revenue for producers.
Kenneth R. Summy of the University of Texas-Pan American and Christopher R. Little of Kansas State University (Manhattan) led a study examining the stresses of a variety of greenhouse plants. The study, published in the August 2008 issue of HortScience, used colour infrared (CIR) photography.
CIR images are divided into wavebands. Ratios are created comparing the NIR wavebands to red wavebands. High NIR and low red values are typical of healthy vegetation because light is being reflected in the proper proportion. Ratios of colours accentuate even slight differences in light reflection, which can indicate disease.
Trifoliate orange, 'Valencia' orange, sour orange, grapefruit, 'Bo' tree, and muskmelon were infested with sooty mold, insects, and pathogens; all are common ailments in greenhouses. Leaves exhibiting a range of symptoms were chosen to compare with healthy leaves of the same species and photographed using CIR.
Certain diseases such as powdery mildew give the leaf surface a powdery finish. Another disease, sooty mold, appears on the leaf as tan, brown, or even black spots. This image analysis allows for detection of these diseases early on. Colour ratio was also affected by the age of the leaf in some cases. The ratios for sour orange leaves that were 10 and 35 days old were significantly different. However, there was no difference between 20- and 35-day-old trifoliate orange leaves. This could affect the efficiency of this method when used on whole-plant foliage.
The study also showed a variation in the accumulation patterns of a particular disease on the two trees in the study. "'Valencia' orange leaves were coated very evenly with insect honeydew, whereas honeydew deposits on 'Bo' leaves were very spotty," reported the researchers. Insect honeydew can contribute to sooty mold growth. As mold infestations increased, the ratio decreased into the unhealthy proportion for all sample plants.
The study points out that this image analysis technology has potential for large-scale use in greenhouses. However, to be most beneficial, the application must be effective in distinguishing the health of plants, cost-effective enough for the purchase of CIR cameras and equipment, and user-friendly so that on-site software processing of data can be completed easily.
Kenneth R. Summy of the University of Texas-Pan American and Christopher R. Little of Kansas State University (Manhattan) led a study examining the stresses of a variety of greenhouse plants. The study, published in the August 2008 issue of HortScience, used colour infrared (CIR) photography.
CIR images are divided into wavebands. Ratios are created comparing the NIR wavebands to red wavebands. High NIR and low red values are typical of healthy vegetation because light is being reflected in the proper proportion. Ratios of colours accentuate even slight differences in light reflection, which can indicate disease.
Trifoliate orange, 'Valencia' orange, sour orange, grapefruit, 'Bo' tree, and muskmelon were infested with sooty mold, insects, and pathogens; all are common ailments in greenhouses. Leaves exhibiting a range of symptoms were chosen to compare with healthy leaves of the same species and photographed using CIR.
Certain diseases such as powdery mildew give the leaf surface a powdery finish. Another disease, sooty mold, appears on the leaf as tan, brown, or even black spots. This image analysis allows for detection of these diseases early on. Colour ratio was also affected by the age of the leaf in some cases. The ratios for sour orange leaves that were 10 and 35 days old were significantly different. However, there was no difference between 20- and 35-day-old trifoliate orange leaves. This could affect the efficiency of this method when used on whole-plant foliage.
The study also showed a variation in the accumulation patterns of a particular disease on the two trees in the study. "'Valencia' orange leaves were coated very evenly with insect honeydew, whereas honeydew deposits on 'Bo' leaves were very spotty," reported the researchers. Insect honeydew can contribute to sooty mold growth. As mold infestations increased, the ratio decreased into the unhealthy proportion for all sample plants.
The study points out that this image analysis technology has potential for large-scale use in greenhouses. However, to be most beneficial, the application must be effective in distinguishing the health of plants, cost-effective enough for the purchase of CIR cameras and equipment, and user-friendly so that on-site software processing of data can be completed easily.
Wednesday, November 4, 2009
What is fertilizer and why do plants need it?
In order for a plant to grow and thrive, it needs a number of different chemical elements. The most important are:
•Carbon, hydrogen and oxygen - Available from air and water and therefore in plentiful supply
•Nitrogen, phosphorus, potassium (a.k.a. potash) - The three macronutrients and the three elements you find in most packaged fertilizers
•Sulfur, calcium, and magnesium - Secondary nutrients
•Boron, cobalt, copper, iron, manganese, molybdenum and zinc - Micronutrients
The most important of these (the ones that are needed in the largest quantity by a plant) are nitrogen, phosphorus and potassium. If you have read the articles How Cells Work and How Food Works, you have heard about things like amino acids, cell membranes and ATP. Nitrogen, phosphorus and potassium are important because they are necessary for these basic building blocks. For example:
•Every amino acid contains nitrogen.
•Every molecule making up every cell's membrane contains phosphorous (the membrane molecules are called phospholipids), and so does every molecule of ATP (the main energy source of all cells).
•Potassium makes up 1 percent to 2 percent of the weight of any plant and, as an ion in cells, is essential to metabolism.
Without nitrogen, phosphorus and potassium, the plant simply cannot grow because it cannot make the pieces it needs. It's like a car factory running out of steel or a road crew running out of asphalt.
If any of the macronutrients are missing or hard to obtain from the soil, this will limit the growth rate for the plant. In nature, the nitrogen, phosphorous and potassium often come from the decay of plants that have died. In the case of nitrogen, the recycling of nitrogen from dead to living plants is often the only source of nitrogen in the soil.
To make plants grow faster, what you need to do is supply the elements that the plants need in readily available forms. That is the goal of fertilizer. Most fertilizers supply just nitrogen, phosphorus and potassium because the other chemicals are needed in much lower quantities and are generally available in most soils. Nitrogen, phosphorus and potassium availability is the big limit to growth.
The numbers on a bag of fertilizer tell you the percentages of available nitrogen, phosphorus and potassium found in the bag. So 12-8-10 fertilizer has 12-percent nitrogen, 8-percent phosphorous and 10-percent potassium. In a 100-pound bag, therefore, 12 pounds is nitrogen, 8 pounds is phosphorous and 10 pounds is potassium. The other 70 pounds is known as ballast and has no value to the plants.
So why don't people need fertilizer to grow? Because we get everything we need from the plants we eat or from the meat of animals that ate plants. Plants are factories that do all of the work to process the basic elements of life and make them available to us
•Carbon, hydrogen and oxygen - Available from air and water and therefore in plentiful supply
•Nitrogen, phosphorus, potassium (a.k.a. potash) - The three macronutrients and the three elements you find in most packaged fertilizers
•Sulfur, calcium, and magnesium - Secondary nutrients
•Boron, cobalt, copper, iron, manganese, molybdenum and zinc - Micronutrients
The most important of these (the ones that are needed in the largest quantity by a plant) are nitrogen, phosphorus and potassium. If you have read the articles How Cells Work and How Food Works, you have heard about things like amino acids, cell membranes and ATP. Nitrogen, phosphorus and potassium are important because they are necessary for these basic building blocks. For example:
•Every amino acid contains nitrogen.
•Every molecule making up every cell's membrane contains phosphorous (the membrane molecules are called phospholipids), and so does every molecule of ATP (the main energy source of all cells).
•Potassium makes up 1 percent to 2 percent of the weight of any plant and, as an ion in cells, is essential to metabolism.
Without nitrogen, phosphorus and potassium, the plant simply cannot grow because it cannot make the pieces it needs. It's like a car factory running out of steel or a road crew running out of asphalt.
If any of the macronutrients are missing or hard to obtain from the soil, this will limit the growth rate for the plant. In nature, the nitrogen, phosphorous and potassium often come from the decay of plants that have died. In the case of nitrogen, the recycling of nitrogen from dead to living plants is often the only source of nitrogen in the soil.
To make plants grow faster, what you need to do is supply the elements that the plants need in readily available forms. That is the goal of fertilizer. Most fertilizers supply just nitrogen, phosphorus and potassium because the other chemicals are needed in much lower quantities and are generally available in most soils. Nitrogen, phosphorus and potassium availability is the big limit to growth.
The numbers on a bag of fertilizer tell you the percentages of available nitrogen, phosphorus and potassium found in the bag. So 12-8-10 fertilizer has 12-percent nitrogen, 8-percent phosphorous and 10-percent potassium. In a 100-pound bag, therefore, 12 pounds is nitrogen, 8 pounds is phosphorous and 10 pounds is potassium. The other 70 pounds is known as ballast and has no value to the plants.
So why don't people need fertilizer to grow? Because we get everything we need from the plants we eat or from the meat of animals that ate plants. Plants are factories that do all of the work to process the basic elements of life and make them available to us
Tuesday, November 3, 2009
Powdery Mildew
Cause: Erysiphe necator (formerly Uncinula necator), a fungal disease common to all areas of the PNW. The disease tends to be more severe on the westside of the Cascades but is a chronic problem in arid districts where over-the-canopy irrigation is used for early-season frost protection or watering. Vitis vinifera (European) cultivars commonly are susceptible to powdery mildew. Other hosts include Boston ivy, Virginia creeper, and Ampelopsis (porcelain berry). The fungus may overwinter as a group of thin threads called hyphae, inside the vine’s dormant buds and/or as small black bodies (chasmothecia) on the exfoliating bark of the vine.
Buds on new shoots can be infected 4 to 6 weeks after shoots start growing but not after bud scales become suberized. These new infected buds remain quiescent until the next growing season. The fungus infects developing buds during the growing season. Shortly after budbreak, the fungus becomes active and covers the emergent shoot with a large white mass of threads or mycelium (“flag shoots”). Flag shoots have rarely been observed in western Oregon or eastern Washington.
Chasmothecia on exfoliating bark release sexual spores during rainy weather above 50oF from budbreak through bloom. This weather also favors infection that results in individual powdery spots, called colonies, on the surface of leaves growing close to the bark.
Many asexual spores (conidia) are produced on the surface of powdery mildew colonies. Under optimal conditions of mild temperatures and high humidity, a single spore can germinate, infect the plant, and produce a new colony and a new crop of spores in 3 days. Temperatures over 85oF inhibit conidia germination. Free water from rain and/or irrigation can wash conidia off of a colony, burst conidia, or result in poor or abnormal germination of the conidia.
Grape berries are highly susceptible from the time calyptras (hoods) fall off to shortly after bloom when berries are about pea size (EL 29 to 31). Susceptibility of the fruit drops rapidly after that time. Grapes do not get new infections on fruit after 8% Brix but can still have sporulation up to 15% Brix. Leaves and canes, however, can be infected up to and past harvest.
Symptoms: Powdery mildew can attack all above-ground plant parts. In early stages, whitish or grayish patches are on leaves and, if severe, ultimately cover both surfaces. Colonies are more easily detected in full sunlight. Later in the season, the mildew darkens and is peppered with minute black dots (chasmothecia). On fruit, the fungus at first may look grayish or whitish but later has a brownish, russeted appearance. Infected fruit cracks and drops from the cluster. Even blossoms sometimes can be infected, causing them to dry up or fail to set fruit. When green shoots and canes are infected, the affected tissues appear dark brown to black in feathery patches. Patches later appear reddish brown on the surface of dormant canes.
Buds on new shoots can be infected 4 to 6 weeks after shoots start growing but not after bud scales become suberized. These new infected buds remain quiescent until the next growing season. The fungus infects developing buds during the growing season. Shortly after budbreak, the fungus becomes active and covers the emergent shoot with a large white mass of threads or mycelium (“flag shoots”). Flag shoots have rarely been observed in western Oregon or eastern Washington.
Chasmothecia on exfoliating bark release sexual spores during rainy weather above 50oF from budbreak through bloom. This weather also favors infection that results in individual powdery spots, called colonies, on the surface of leaves growing close to the bark.
Many asexual spores (conidia) are produced on the surface of powdery mildew colonies. Under optimal conditions of mild temperatures and high humidity, a single spore can germinate, infect the plant, and produce a new colony and a new crop of spores in 3 days. Temperatures over 85oF inhibit conidia germination. Free water from rain and/or irrigation can wash conidia off of a colony, burst conidia, or result in poor or abnormal germination of the conidia.
Grape berries are highly susceptible from the time calyptras (hoods) fall off to shortly after bloom when berries are about pea size (EL 29 to 31). Susceptibility of the fruit drops rapidly after that time. Grapes do not get new infections on fruit after 8% Brix but can still have sporulation up to 15% Brix. Leaves and canes, however, can be infected up to and past harvest.
Symptoms: Powdery mildew can attack all above-ground plant parts. In early stages, whitish or grayish patches are on leaves and, if severe, ultimately cover both surfaces. Colonies are more easily detected in full sunlight. Later in the season, the mildew darkens and is peppered with minute black dots (chasmothecia). On fruit, the fungus at first may look grayish or whitish but later has a brownish, russeted appearance. Infected fruit cracks and drops from the cluster. Even blossoms sometimes can be infected, causing them to dry up or fail to set fruit. When green shoots and canes are infected, the affected tissues appear dark brown to black in feathery patches. Patches later appear reddish brown on the surface of dormant canes.
Monday, November 2, 2009
Oxygen Plant / Nitrogen Plant
The oxygen nitrogen gas plant are safe and economical & operate with an expansion engine which lowers the operating pressure up to 30-40 kg/cm, lowers the power consumption and is trouble free. The oxygen and nitrogen plant mainly consists of AIR COMPRESSOR (Innersole Rand) Molecular sieve battery for removal of acetylene and hydrocarbons from the process air and eliminating the use of caustic soda and cost saving as there is no need of any recurring cost of chemicals. The production plant can produce both OXYGEN & NITROGEN simultaneously and the plant BDM models have a Built-in internal compression liquid oxygen pump to fill bone dry high pressure oxygen up to 165 kg/cm in cylinders.
Silent Features of Oxygen/Nitrogen Gas Plant
Very simple to operate
No raw material is required
Trouble free operation for years (German design)
Easy availability of spare parts
Low power consumption
Production of oxygen & nitrogen simultaneously without use of bulky gas holders.
Latest molecular sieve technology without recurring cost of chemicals
Oxygen and Nitrogen Plants also in stainless steel colum
Process Description of BDM Oxygen Nitrogen Plant
The free atmospheric air is sucked in the nitrogen oxygen gas plants by a multi-stage air compressor through a filter and compressed to the working pressure. After each stage, intermediate coolers and water separators are provided. The compressed air then passed through the evaporation pre-cooler and then to the molecular sieve battery where the moisture and carbon di-oxide are removed from the process air. It then passes through the heat exchanger No.1 where it is cooled by the out-going waste nitrogen gas and product oxygen produced in the oxygen gas plants.A part of this cold air then flows through an expansion machine and the balance through the 2nd heat exchanger. The ratio of the two air streams is controlled by an expansion valve, RI. Both these streams of air then unite in the medium pressure column where it partially liquefies.
Silent Features of Oxygen/Nitrogen Gas Plant
Very simple to operate
No raw material is required
Trouble free operation for years (German design)
Easy availability of spare parts
Low power consumption
Production of oxygen & nitrogen simultaneously without use of bulky gas holders.
Latest molecular sieve technology without recurring cost of chemicals
Oxygen and Nitrogen Plants also in stainless steel colum
Process Description of BDM Oxygen Nitrogen Plant
The free atmospheric air is sucked in the nitrogen oxygen gas plants by a multi-stage air compressor through a filter and compressed to the working pressure. After each stage, intermediate coolers and water separators are provided. The compressed air then passed through the evaporation pre-cooler and then to the molecular sieve battery where the moisture and carbon di-oxide are removed from the process air. It then passes through the heat exchanger No.1 where it is cooled by the out-going waste nitrogen gas and product oxygen produced in the oxygen gas plants.A part of this cold air then flows through an expansion machine and the balance through the 2nd heat exchanger. The ratio of the two air streams is controlled by an expansion valve, RI. Both these streams of air then unite in the medium pressure column where it partially liquefies.
Sunday, November 1, 2009
Plants make
Plants make oxygen
One of the materials that plants produce as they make food is oxygen gas. This oxygen gas, which is an important part of the air, is the gas that plants and animals must have in order to stay alive. When people breathe, it is the oxygen that we take out of the air to keep our cells and bodies alive. All of the oxygen available for living organisms comes from plants.
Plants provide useful products for people
Many plants are important sources of products that people use, including food, fibers (for cloth), and medicines. Plants also help provide some of our energy needs. In some parts of the world, wood is the primary fuel used by people to cook their meals and heat their homes. Many of the other types of fuel we use today, such as coal, natural gas, and gasoline, were made from plants that lived millions of years ago.
Plants make food
Plants are the only organisms that can convert light energy from the sun into food. And plants produce ALL of the food that animals, including people, eat. Even meat. The animals that give us meat, such as chickens and cows, eat grass, oats, corn, or some other plants
One of the materials that plants produce as they make food is oxygen gas. This oxygen gas, which is an important part of the air, is the gas that plants and animals must have in order to stay alive. When people breathe, it is the oxygen that we take out of the air to keep our cells and bodies alive. All of the oxygen available for living organisms comes from plants.
Plants provide useful products for people
Many plants are important sources of products that people use, including food, fibers (for cloth), and medicines. Plants also help provide some of our energy needs. In some parts of the world, wood is the primary fuel used by people to cook their meals and heat their homes. Many of the other types of fuel we use today, such as coal, natural gas, and gasoline, were made from plants that lived millions of years ago.
Plants make food
Plants are the only organisms that can convert light energy from the sun into food. And plants produce ALL of the food that animals, including people, eat. Even meat. The animals that give us meat, such as chickens and cows, eat grass, oats, corn, or some other plants
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