DIVISION OF AGRICULTURAL SCIENCES AND NATURAL RESOURCES
"The OAES is an ever-changing world of scientific investigations, new product development, and studies of programs and technology to benefit people."
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Computerized modeling programs, machines capable of "vision," and instruments that can synthesize a biomolecule are as real and on-line in Oklahoma Agricultural Experiment Station (OAES) laboratories these days as are voice mail, telecommunications, and the Internet. OAES, the research arm of the Division of Agricultural Sciences and Natural Resources, not only embraces new technologies but also, by necessity, must be a leader in its application in order to compete for research funds from across the nation.
However, OAES researchers must also "keep their feet on the ground," so to speak, in continuing the applied aspects of research that have made our nation's farms and ranches the most productive in the world. As new technology becomes available, OAES scientists quickly adapt new techniques to work harmoniously with the old. The result is a dynamic interfacing of the novel and the dependable that gets results.
Computerized Modeling Systems
Predicting Forest Conditions
For example, forestry researchers spent some eight years physically collecting tree growth and management information on shortleaf pine plots. Cooperating with the U.S. Forest Service, data was accumulated from some 200 plots located across eastern Oklahoma and western Arkansas. Now the researchers are able to use a computerized modeling system to predict forest conditions under various management schemes for 10-15 years ahead--and this can be done for any piece of forest land in minutes.
Providing Rural Development Scenarios
From molecules to markets, computer modeling systems provide researchers with clear estimates of situations in a short time that once required years to accomplish. OAES agricultural economists use them to help rural communities strengthen their economies. A model can provide several rural development scenarios for a community, as well as the effects of variations on each.
Determining Trout Fishery Impacts
OAES agricultural economists made use of such a system to help the Oklahoma Department of Wildlife Conservation determine the impact of a trout fishery on the Mountain Fork River below the Broken Bow dam. OAES studies show that society receives $6 of benefit for every $1 invested in trout fishing in the area. The economic development model the researchers created enable decision makers to foresee results of management techniques regarding the fishery.
Integrating Pest Management Practices
Another project uses a computer modeling system to help landowners integrate pest management practices on the watershed system within a field. The Pesticide Economic and Environmental Tradeoff (PEET) system was developed and implemented cooperatively by researchers in Oklahoma, Florida, and North Carolina. It involves compromises between economic gain and risk to ground water on a single crop grown primarily on one type of soil.
Controling Weeds
Expanding on that effort, the next step of the project will deal with watersheds of various soils that are simultaneously under management systems for weeds, insects, diseases, and even endangered species habitat. This first step in the new study is looking at weed control. When complete, the new system will incorporate geographic information enabling the user to establish the boundary of a given field and apply the decision support system as needed.
For example, a landowner will have a summary of data for weed control, the economic impact of the reduction a crop would suffer without the control, and the impact of each treatment on ground water quality to determine the best scenario for the operation at the time--and all that information can be delivered via a personal computer within a few minutes.
Turfgrass Research
Identifying Genes
Turfgrass researchers in the OSU Department of Agronomy are combining the traditional applied aspects of plant breeding with molecular genetics to try and create pasture grass that is more digestible to animals. The first steps were to identify the gene that controls lignin content in pasture bermudagrass and then to try to "turn it down" using genetic manipulation.
Using Biolistics
The manipulation in this case was biolistics, which means the use of a gene gun to literally "shoot" a particle covered with desirable DNA pieces into a plant, then grow out cells--and ultimately plants--containing the new genetic material. Once that is accomplished, traditional plant breeding methods can be used to incorporate the trait into a productive bermudagrass variety. When researchers first began working on the project, they had a 1:1,000 success ratio in getting the DNA successfully introduced into plant cells. With experience and training, they are now working at about a 1:10 success ratio.
Developing Cold-Tolerant Grasses
In a similar vein, agronomy and horticulture researchers are working with USDA scientists to develop a more cold-tolerant bermudagrass variety. The long-term goal is to develop a variety that can withstand Oklahoma's coldest temperatures and still come back heartily in the spring. Although this study is largely funded by the U.S. Golf Association, the cold-tolerant trait would also greatly benefit pasture bermudagrasses.
Producing Better Biomass
OAES agronomy researchers are using a wild relative of the wheat plant to try and develop a variety that will produce more biomass, namely the wheat grain, although increased forage amounts also would be desirable. Emmer, a plant known since ancient times, is considered to be an ancestor of modern wheat. An Israeli researcher with the University of Haifa gathered wild emmer from his country and shipped it to OAES scientists for this study.
The emmer plant is known for its high photosynthesis rate, and researchers hope they can transport that trait into wheat selections here. Using genetic technology, OAES researchers have been able to move the gene, but they have found that it is hard to get it expressed in the resulting wheat crosses. They have had some success, however, and when they do, plant breeding techniques will be used to produce wheat plants that grow more grain and forage with essentially the same inputs.
Researching Stomates
When such high-production wheat plants are in place, they will by necessity have to make better use of water, as will regular wheat plants if they are to be coaxed into greater production. OAES scientists are using stable carbon isotope technology to determine if a plant's photosynthetic capacity is the result of the action of the stomates, tiny openings in plant leaf surfaces that allow water and gasses to escape, or of the biochemical efficiencies (or inefficiencies) of the photosynthetic mechanisms.
Pecan Research
Extending the Self Life
Through technology used to extract caffeine from coffee, OAES researchers have extracted oil from pecans. The initial goal was to extend the shelf life of pecans in stores, but this study, supported in part by the Oklahoma Council for the Advancement of Science and Technology (OCAST) and the USDA, is proving to be a win-win-win situation. First of all, the extraction process itself is relatively new, using carbon dioxide rather than hexane, which isn't as environmentally friendly.
Reducing Fat and Calories
Second, a survey of the industry indicated that marketers would be interested in a low-fat pecan in order to create products such as pecan pie with reduced fat and calories. As it turns out, pecan oil contains about twice the amount of calories as sugar. Extracting about 30-35% of the pecan oil reduces the calorie content significantly. In addition, the shelf life was extended significantly, which was the original goal. An extra bonus is that the pecan oil is high in polyunsaturated fatty acids, similar in quality to olive oil.
Testing the Product
OAES researchers from the College of Human Environmental Sciences, agricultural engineering, and horticulture are looking forward to conducting a commercial batch test of 2,000 pounds of pecans soon. They are coordinating efforts with pecan industry personnel to test market the reduced-fat pecans and the pecan oil as commercial products.
Seed Germination Technology
Developing New Matrices
OAES researchers from the OSU departments of plant pathology and forestry are adapting seed germination technology used to help agronomic and horticultural crops emerge more uniformly and at a higher percentile rate to do essentially the same thing for trees. Working with an OCAST grant, they are developing a solid matrix seed priming system that also will carry beneficial biological control agents.
Incorporating Biological Controls
Experiments with ground coal and clay as a matrix have shown some success, and other carriers are under observation. Biological control agents such as Trichoderm harzianum, a beneficial fungi, may establish and grow in the area as the seed germinates and grows. The result is built-in protection that protects not only the seed but also some of the root area as the plant expands.
Increasing Seed Efficiency
The goal of this research is to increase seed efficiency in large tree nurseries. With some seed costing several hundred dollars per pound, as small as a 10% increase in germination rate can mean thousands of dollars in savings to a large nursery. In addition, evenly germinated trees mean a more uniform stand, which is easier to fertilize, to irrigate, and to harvest.
Molecular "Fingerprints"
Indentifying Look-Alike Insects
Molecular "fingerprints" are being used to help OAES entomologists and biochemists develop a system that will enable them to quickly identify look-alike insects. Aphids, for instance, look a lot alike and can be impossible to visually identify. Scientists spend a lot of money and effort to bring in parasitoids, such as wasps and lady beetles, as biological controls on insects such as aphids. Many of these parasitoids are also hard to identify. Identification is necessary in order to know if the biologicals are surviving and building in population.
Establishing a "Library"
Hydrocarbons found in the waxy substance that coats the cuticle, or outer layer of shell on parasitoids, aphids, and other insects are unique to each species and biotype. With taxonomy as a specialty on the decline, it can take six months to have an insect identified. Using cuticular hydrocarbons, or another method known as Random Amplified Polymorphic-Polymerase Chain Reaction (RAPD-PCR), scientists can be sure of the insect with which they are working.
RAPD-PCR is currently used to identify bacteria and is being adapted over to use in identifying insects. Working in a project that began with OCAST funding and is now being continued with cooperation from USDA, the OAES researchers hope to establish a "library" of these molecular fingerprints so that an insect brought in from the field can be identified quickly via matching markers in a book or on computer.
Biological Controls
Studying Stored Grain Insects
Biological controls are playing an important role in stored grain elevators in Oklahoma, but just how much of a role wasn't known until OAES entomologists, agricultural engineers, and agricultural economists conducted several years worth of studies looking at stored grain insects, then at how effective the parasites are at controlling them.
Developing the Stored Grain Adviser
Agricultural researchers from Kansas, Oklahoma, and the USDA-ARS developed an expert modeling system called Stored Grain Adviser that helps grain bin and elevator operators make decisions regarding combinations of drying, temperature, fumigation, and other measures to control stored grain insects.
Examining Oklahoma's Use of Biologicals
However, it wasn't until more recently that OAES researchers began to learn of Oklahoma's unique position to make use of biologicals. These are parasites that already exist in grain elevators and thus do not have to be reared, purchased, shipped, or otherwise handled. They learned that Oklahoma's frequent combination of summer heat, dryness, winds, and other climatic factors favor the parasitoids, and grain owners have only to be careful not to damage populations of the beneficial insects in order to gain good stored grain insect control. Studies continue on the best ways to manage the stored grain for economical and adequate control of these pests.
Boll Weevil Control
Surveying Eradication Possibilities
As it turns out, Oklahoma's climate and close management will be important factors in controlling another important insect--the boll weevil. OAES entomologists, agricultural economists, agricultural engineers, and USDA scientists conducted a survey of the pending boll weevil eradication program as far as how it will affect Oklahoma. Researchers say they approached the survey feeling that it would not be all that economically feasible here, but they changed their thinking after viewing the data.
Using Efficiency Models
Geographic and water efficiency models were used to help map every acre of Oklahoma cotton land and develop predictions of the boll weevil eradication program on them. Because of Oklahoma's dryness, and then because of it's penchant for becoming very wet very rapidly, management and timing will be imperative to successfully meet eradication goals while being conscientious of the environment. With careful management, however, Oklahoma cotton producers will benefit from the program.
Evapo-Transpiration
Developing a Monitoring System
Huge quantities of water evaporate from on and under the earth's surface every day, but we don't pay a lot of attention to it because it can't be seen as it occurs. OAES agricultural engineers and soil scientists are paying attention. In fact, they are working to develop a system for monitoring the evapo-transpiration from the earth to the atmosphere over large land areas.
Measuring Lost Water
Using devices called weighing lysimeters located in the four quadrants of the state, the researchers can actually measure the amount of water lost from the soil in a given space of time. The lysimeters are tanks placed in a field with the same soil, plants, and cultural conditions within it as are found in the surrounding area. Whatever happens to soil in the lysimeter also is happening to soil in the surrounding area.
Providing Rapid Information
The Oklahoma Mesonet system of around-the-clock instant weather monitoring is an important facet of this study. With it, researchers in Stillwater can quickly and accurately measure the amount of solar radiation being received at the lysimeter sites. This data, combined with the actual field data, will help develop a model that can provide rapid information for decisions on irrigation, fertilizer application, planting times, and other land use strategies.
Predicting Soil Moisture
The ultimate goal is to be able to describe evapo-transpiration over large areas and predict over short and long intervals how it will influence soil moisture. Aside from the obvious direct agricultural benefits, it will also help with decisions regarding drought condition assessment and flood control, since dryer ground absorbs much more rainfall before runoff occurs.
Meeting Production Needs
The newest technology in weather monitoring is being used to determine the effects of climate and irrigation strategies on peanut production. OAES agricultural engineers and agronomists are using the Mesonet system of continuous weather monitoring combined with field measurements of soil moisture, root length density, applied irrigation water, and growth stages to create an accurate model for peanut production. Using the gathered data, the model will be calibrated to meet the production needs of Oklahoma peanut cultivars, soils, climatic conditions, and irrigation practices.
Investigating Cercospora Leafspot
Moisture and temperature conditions play an important role in the development of Cercospora leafspot on peanuts. OAES and USDA plant pathologists are working to establish spray thresholds, points at which peanuts can most effectively and economically be treated to prevent the diseases. Their work established an "infection hour," a condition of favorable growth for the leafspot fungus for a period of one hour. An infection hour is a period of 95% or more humidity combined with a temperature range of 61-86 degrees F for one hour.
For runner type peanuts, which have partial resistance to leafspot, 48 infection hours were required to produce the onset of Cercospora leaf spot. The researchers sprayed immediately when the 48-hour threshold was reached, then waited 10 days. When the next 48-hour period was reached, they re-sprayed. This method provided good disease control with a minimum number of sprayings.
On susceptible spanish cultivars, the researchers noticed small amounts of Cercospora leafspot after 24 infection hours of exposure and significant amounts after 36 hours. On the less susceptible runner cultivars, Florunner and Okrun, similar amounts were present only after 36 and 48 hours respectively. The goal of this research is to reduce the number of sprays required and to be able to give advisories, via Oklahoma Cooperative Extension Service county directors, to growers.
Examining Sclerotinia Blight
Work with sclerotinia blight, however, gave different results. Soil temperature and moisture conditions also are good predictors for this peanut soil-borne disease, but it is the spanish type peanuts that generally are more resistant. Sclerotinia blight invariably showed up about a week after the following conditions were met: when the plants had grown just about to the point where the canopies of rows were about to touch, with the temperature at a high of 82.4 degrees F or less, and the crop had received an irrigation or rain of a half-inch or more.
Unfortunately, those conditions are met much of the time during the peanut growing season in Oklahoma. Studies show that yields with sclerotinia blight-resistant varieties such as Tamspan 90 are increased only about 15% when a labeled fungicide was also used and about 30% with the Spanco peanut. This did not justify the expense of spraying, although the 80-90% yield reductions the disease can cause on susceptible lines such as Florunner and Okrun may mean the difference between having a crop or not.
Wheat Aphid Research
Determining Relationships
Agricultural researchers constantly work to find ways to reduce the number and amounts of chemicals used to treat plant and animal problems, whether diseases or insects. One of the most intensive battles over the years has been waged against aphids, and the wheat aphid, or greenbug, is certainly one of the hardest to control.
Most recently, OAES horticulture and entomology scientists have been trying to find out what it is in the greenbug's feeding on wheat plants that causes the characteristic yellowing and killing off of the leaf tissue. Knowing that ethylene, a plant hormone, promotes fruit ripening and the aging--and thus yellowing--of leaf tissue, the researchers decided to see if the insect's feeding triggered ethylene production by the wheat plants, which in turn would cause the senescence associated with greenbug damage.
Eliminating Possibilities
In work funded in part by the Division's Targeted Research Initiatives Program, results showed that the feeding does trigger ethylene production and that some biotypes of greenbugs cause more ethylene presence in the tissue than do others. However, they learned that the ethylene did not cause the damage; it was co-incidental to the feeding. The ethylene was not even necessary for senescence to occur. This meant the feeding activities cause damage and death to the leaf tissue in some other manner.
Investigating the Feeding Methods
Now researchers are looking at exactly how these hardy and adaptable insects actually go about feeding. It seems that though greenbugs pierce the plant with their stylus, or mouthparts, the piercing is not a function of force and sharpness. The insects seem to "digest" their way between plant cell walls with various enzymes breaking down the pectin that holds the plant together.
Increasing Plant Resistance
By taking pieces of these digested cell walls and fractionating the pectin, then introducing that back into the leaf tissue, researchers have been able to see some senescence produced. The ultimate goal of this work is to reduce the pesticides needed to control greenbugs. More than that, however, it also is to try and identify the mechanisms of plant injury caused by the greenbugs and how the plant can be made resistant to these mechanisms. If this can be done, the researchers will have a targeted approach to increasing plant resistance.
Brucella Abortis Research
Investigating the Cell's Nature
Battles against insects are usually waged on the wheat field or that of some other crop. But there are also unseen battles in nature, such as the one OAES biochemists are studying within the cells of cattle. Brucella abortis, the causative organism of brucellosis in cattle, lives within the macrophages, or large guard cells that are part of the animal's immune system. The fact that they exist there is unique, since the macrophage usually destroys such intruders. But the real problem is that other entities in the immune system and drugs can't reach the organism, thus the disease can hang on for a long while.
Scientists theorize that the B. abortis cells must control something inside of the macrophage. The researchers grew macrophages under laboratory conditions and introduced B. abortis organisms labeled with a radioactive genetic marker. They discovered that B. abortis cells grown outside of the macrophages were different from those taken from inside.
Identifying Proteins
There was a wide variety of activity taking place in the proteins of the B. abortis cells grown inside the macrophagesÑsome of the proteins disappeared, others appeared, some increased in number, while others decreased. The scientists are not yet sure what it all means, but they are currently working to identify the proteins. When the mystery of the proteins is unraveled, they may be able to learn how the organism can survive inside the macrophage and how to gain some control over it.
Milk Research
Evaluating Productions Differences
OAES animal scientists are involved in a project cooperating with agricultural experiment stations from the other states in the Southern Region in which they are looking at the expected progeny difference (EPD) for maternal performance of angus sires. Specifically, the researchers have evaluated the differences in calves from mothers with high milk production versus those with low production.
As expected, calves from higher-producing mother cows do better, to the point that milk EPD is actually expressed in terms of weaning weight. Further work showed that the higher-producing cows are generally in poorer body condition than the lower-producing cows. The question now is, will the higher milk production tendency reduce the cow's body condition enough overall to result in poor reproductive performance? The scientists say learning that step is next, and it will be an important one to being able to advise cattlemen on the economics of mother cows.
Removing Serum Cholesterol
Milk also is the focus of a study being conducted by OAES diary food researchers. The milk industry is very interested in work being done with an organism known as Bifidobacterium longum, which is a dietary adjunct to milk and other dairy products. The organism has exhibited the potential to remove serum cholesterol in humans.
An organism that can be found naturally existing in the digestive tract of humans, B. longum is currently under study at OSU with the objective being to develop procedures to commercially produce the product and insure that it will stay alive in food until it is consumed. It is hoped this work will lead to the development of cultures beneficial to the control of serum cholesterol in people.
Optical Sensors Development
Optical sensors linked to computers are being used by OAES agronomists, agricultural engineers, and agricultural economists to create "smart" machinery that can actually determine if a plant should be sprayed with herbicide or whether or not to apply liquid fertilizer to specific areas of a wheat field.
Spraying Weeds
Right now, the equipment is being used on fallow fields and can differentiate between green plants and the soil. Whenever a weed is passed over, it receives a shot of herbicide. Because the spot is isolated, the herbicide can be applied at higher rates than those used for blanket spraying. The result is less money spent for herbicide, better control of the weed in question, and a weed control situation that is more environmentally friendly.
Fertilizing Plants
The same is true when the equipment is used to apply liquid fertilizer. As the sprayer is pulled over a wheat field, the optical sensor is "reading" the color of the wheat plants beneath by measuring reflected wavelengths. When it detects the lighter color of nitrogen-poor wheat, an optimal spot application is applied only in amounts needed by the wheat plants. The researchers are still trying to determine the smallest area they can accurately treat with this method, but they know it is a matter of square feet rather than acres.
Developing International Standards
Not only is this work supported by the OAES but also by the wheat producers themselves with funding from the Oklahoma Wheat Research Foundation, which is financed by check-off monies from wheat produced, and by the Oklahoma Soil Fertilization Research and Education Advisory Board, which comes from a check-off on fertilizer sales. Also, the Equipment Manufacturer's Institute has been supportive of OAES work to develop international standards for this type of equipment.
An Ever-Changing World
The OAES is an ever-changing world of scientific investigations, new product development, and studies of programs and technology to benefit people. While it sometimes takes many years for results in a specific program to surface, studies are ongoing so that accomplishments continue to surface year after year. When they do, all of society benefits, whether the results in question are aimed at farms, industry, or individuals.
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