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AGRICULTURE AND PLANT SCIENCE.

Chair: Franklin O. Chukwuma, Alcorn State University

Vicechair: Maria T. Begonia, Jackson State University

FRIDAY MORNING

Imperial Room

9:00 INVESTIGATION OF EDIBLE PLANTS AND THEIR ANTI-OXIDANT EFFECTS

Lovell E. Agwaramgbo, Tougaloo College, Tougaloo, MS 39174

Oxidative processes (LDL & Lipid peroxidation) have been implicated in the onset of many cardiovascular diseases, cancer, diabetes, and aging. Many studies have reported that some compounds tend to slow down some of these processes. This investigation examined the ability of edible plants and vitamin E to inhibit oxidation under mild and harsh conditions. Reactions were carried in the presence and absence of plant materials and vitamin E, respectively. The results suggest that not all plants have anti-oxidant potential under our reaction conditions. Many plants that contain vitamins A & C did not inhibit oxidation. This may suggest that these vitamins may not be anti-oxidants, especially for our systems but may be precursors or activators of the anti-oxidant activity of other substrates. Acknowledgments: 1. BUSH Foundation Case Studies, 2. UNCF service Learning, 3. Tougaloo College Organic II Students, 4. Tougaloo College Title III Curriculum Enhancement/Academic Support

9:15 DETERMINATION OF METABOLIC RATES OF GERMINATING PHASEOLUS VULGARIS SEEDS AT DIFFERENT TEMPERATURE

Julius O. Ikenga, Mississippi Valley State University, Itta Bena, MS 38941

This research was designed to determine the metabolic rates of germinating seeds of Phaseolus vulgaris at 26[degrees]C and 14[degrees]C. Phaseolus vulgaris is a common kidney beans and a staple in human diet. It is valued as a cash crop and for its high protein and vitamin contents. Living organisms carry out several chemical processes that are essential for continued growth and development. These essential chemical processes constitute metabolism. Much of the metabolic processes occur in the mitochondria of cells and use oxygen as the final electron acceptor. Such chemical processes are termed aerobic respiration. Ripened seeds respire and give off [CO.sub.2] as a by-product. We used the indirect respirometry technique to measure the rate of [CO.sub.2] that P. vulgaris respired in ppm/min. First, the seeds were soaked overnight in water and ripened for three days in a dark chest at 26[degrees]C. Twenty germinating seeds were blotted dry with paper towels and then placed in a respirometer bottle. The latter was tightly capped with a rubber stopper fitted with a Vernier [CO.sub.2] Gas Sensor Probe. The Probe was interfaced with a Vernier LabPro[TM] and set to collect 30 samples over a five minutes period. The above procedures were carried out again except that respirometry was done at 14[degrees]C. The control was carried out as above at 26[degrees]C using 25 non-ripened seeds of P. vulgaris. The metabolic rate of the germinating P. vulgaris seeds was found to be 362 ppm [CO.sub.2]/min. At 14[degrees]C, the metabolic rate dropped to 147 ppm [CO.sub.2]/min. The non-ripened seeds (control) showed a metabolic rate of 2 ppm [CO.sub.2]/min.

9:30 DISCOVERING SOYBEANS AND HEALTH

Juliet G. Huam [1], Koretta [Kitchens.sup.*] [1], George T. Bates [1], Wanda L. Dodson [2], and Laura D. Salazar [2], (1.) Alcorn State University, Alcorn State, MS 39096 and (2.) Mississippi State University, Mississippi State, MS 39762

Soybean is gaining in popularity as a substitute for animal protein and as a healthy food. Asians consumed 20-50 times more soy-based food per capita than Americans. This type of diet accounted for lower incidence of several chronic degenerative diseases in Asian countries compared to that of the United States. The objective of this paper is to examine the potential health benefits of soy protein. Soy products contain high quality protein, vitamins, minerals and isoflavone, a phytochemical. These soy products are low in saturated fat, have no cholesterol and are high in fiber content. Soy products, such as tofu, and soy concentrates have been associated with lowering cholesterol level, preventing coronary heart diseases, and reducing the incidence of breast, colon, prostate and endometrial cancer. Soy products have also been known to fight against osteoporosis, alleviate menopausal symptoms, and enhance overall human immune systems. Studies have shown that a low saturated fat diet that includes about 30-50 g rams of soy protein per day may reduce the risk of coronary heart disease. The U.S. Food and Drug Administration also supports this soy protein health claim. Incorporating soy protein into the diet may be beneficial to our general health.

9:45 FRESH WATER VIRAL DENSITIES IN NORTH MISSISSIPPI

Allison [Grisham.sup.*] and Clifford Ochs, University of Mississippi, University, MS 38677

In recent years it has been discovered that viruses are a major cause of mortality for planktonic bacteria in marine systems and have significant effects on nutrient cycling and energy flow. The ecological role of viruses in freshwater systems is poorly known. In this study, we determined densities of viruses from four freshwater lakes and examined empirical relationships of viral densities with bacterial density, algal biomass, and temperature. Samples from the surface water of the lakes were collected in March, June, August, and November 1999. The greatest density of viruses was 18.7x[10.sup.6]/ml in March. Lower densities, ranging from 0.4x[10.sup.6] to 4.0x[10.sup.6] viruses/ml, were observed during the rest of the year. Viral densities in the four lakes were significantly positively related to algal biomass but not to bacterial density. In February and June 1999, samples were also collected across an environmental gradient beginning with the headwaters of a spring, through the receiving pond, and into t he creek draining the pond. In contrast to the seasonal pattern observed for the other lakes, viral densities in June exceeded 20x[10.sup.6]/ml, whereas in February viruses were generally less than 5x[10.sup.6]/ml at all sites across the gradient. For both dates, viral densities were significantly positively related to bacterial concentration.

10:00 Break

10:15 MULCHING FOR WEED CONTROL IN FIELDGROWN FEVERFEW

Patrick E. Igbokwe, Cherie [Edwards.sup.*], and Magid Dagher, Alcorn State University, Alcorn State, MS 39096

Two synthetic (Black Plastic and Weed Barrier) and one organic (Pine Bark Nuggets) mulching materials were evaluated for purple nutsedge control in field-grown feverfew (Tanecetum parthenium). Mulching effect on feverfew growth, yield, mineral composition and soil characteristics were also investigated. The study was conducted at the Alcorn State Experiment Station. The soil type is Memphis silt loam. A completely randomized design with three replications were used in this study. Findings suggest that Feverfew planted in southwest Mississippi during the fall planting season will overcome the region's mild winter, grow to maturity in the following spring, producing numerous, small, daisy-like heads of yellow flowers with outer rays. Both 6-mil black plastic and weed barrier will provide better control of purple nutsedge in field-grown feverfew in the fall and early spring, resulting in overall better plant growth and development than pine bark nuggets.

10:30 C:N RATIOS AND RATE OF DECOMPOSITION OF BRASSICA JUNCEA RESIDUES

Cedric A. [Sims.sup.*] [1], Girish K. Panicker [1], Alton B. Johnson [1], Diane E. Stott [2], Ahmad H. Al-Humadi [1], and Jesse Harness [1], (1.) Alcorn State University, Alcorn State, MS 39096 and (2.) USDA-ARS, NSERL, Purdue University, West Lafayette, IN 47907

Crop residues are the major and often the only input of carbon in farmland soils. Residue management has been established as a valuable technology for reducing erosion. As a part of the erosion prediction studies being conducted on horticultural crops in Mississippi, root or shoot residues of Spring Mustard (Brassica Juncea) were placed in fiberglass mesh bags either at the surface or 15 cm deep in a Memphis silt loam soil (Typic Hapludalf) and was allowed to undergo decomposition over a 6 month period. Bags with decayed samples were collected randomly from the field every 10 days and analyzed for organic carbon and nitrogen. While both root and shoot residues on the surface maintained high C:N ratios ([greater than]20) throughout the six months, the subsurfaced shoot reached a low C:N ratio ([less than]20) in the fourth month and it further lowered the C:N ratio in the succeeding months. The C:N ratios of the subsurfaced root were lower than the surfaced root after one month of application and it maintained the ratios close to 20 in the succeeding periods. Subsurfaced residues decomposed faster than surfaced residues. The decomposition rates of both subsurfaced root and shoot were negatively correlated with the low C:N ratios.

10:45 C-FACTOR RESEARCH FOR EROSION PREDICTION MODELS: PHILOSOPHY AND METHODOLOGY OF DATA COLLECTION

Girish K. [Panicker.sup.*] [1], S.C. Tiwari (Rtd) [1], G.A. Weesies [2], Diane E. Stott [3], Ahmad H. Al-Humadi [1], Cedric A. Sims [1], Liang C. Huam [1], Patrick E. Igbokwe [1], O.P. Vadhwa [1], Alton B. Johnson [1], Jesse Harness [1], J. Bunch [4], and T.E. Collins [5], (1.) Alcorn State University, Alcorn State, MS 39096; (2.) USDA-NRCS, NSERL, Purdue Universtiy, West Lafayette, IN 47907; (3.) USDAARS, NSERL, Purdue University, West Lafayette, IN 47907; (4.) USDA-NRCS, NPDC, Baton Rouge, LA 70874; and (5.) USDA-NRCS, Jackson, MS 39269

The increased demand for food, fiber and fuel, due to population increase, is causing marked acceleration of soil erosion. The Universal Soil Loss Equation (LISLE) and its replacement, the Revised Universal Soil Loss Equation (RUSLE), are the most widely used of all soil erosion prediction models. Of the five factors in RUSLE, the cover and management (C) factor is the most important one from the standpoint of conservation planning because land use changes meant to reduce erosion are represented here. Even though the Revised Universal Soil Loss Equation (RUSLE) is based on the LISLE, this modern erosion prediction model is highly improved and updated. Alcorn State University entered into a cooperative agreement with the NRCS of USDA in 1988 to conduct C factor research on vegetable and fruit crops. The main objective of this research is to collect plant growth and residue data that are used to populate databases needed to develop C factors in RUSLE, and used in databases for other erosion prediction and natu ral resource models. The enormous data collected on leaf area index (LAI), canopy cover, lower and upper biomass, rate of residue decomposition, C:N ratio of samples of residues and destructive harvest and other growth parameters of canopy and rhizosphere made the project the largest data bank on horticultural crops. The philosophy and methodology of data collection will be presented.

11:00 INCIDENCE OF SPLITTING IN 'PREMIER' AND 'TIFBLUE' RABBITEYE BLUEBERRIES

D.A. [Marshall.sup.*] [1], Kenneth J. Curry [2], and James M. Spiers [1], (1.) USDA-ARS Small Fruits Research Station, Poplarville, MS 39470 and (2.) University of Southern Mississippi, Hattiesburg, MS 39406

Berry splitting, resulting in poor fruit quality, often occurs in rabbiteye blueberries (Vaccinium ashea Reade) after a significant rainfall, even in plants that were sufficiently irrigated. This splitting appears to vary between cultivars. To simulate an excessive rainfall, two rabbiteye blueberry (Vaccinium ashei Reade) cultivars 'Tifblue' (considered more susceptible to splitting) and 'Premier' (considered less susceptible) were subjected to varying soil moisture levels. Fruit were immersed in distilled (to emulate rainwater) and tap (overhead irrigation) water. 'Premier' is more likely to split if fruit are developed on plants in moist soil conditions, while soil moisture levels do not affect 'Tifblue' splitting. Both 'Premier' and 'Tifblue' are more likely to split if immersed in distilled water (rain) as opposed to tap water (overhead irrigation). Splitting apparently does not occur in either cultivar from excessive irrigation alone. In this study we correlates the frequency of splitting to fruit quali ty measurements such as soluble solid content, total solids, titratable acidity, pH, and force needed to split an intact berry. We anticipate that this will be a contribution to more constraining breeding parameters not only for rabbiteye blueberry, but also for other blueberries being developed such as the southern highbush.

11:15 ACTIVITY OF THE FUNGUS COLLETOTRICHUM FRAGARIAE IN THE EARLY STAGES OF INFECTION IN STRAWBERRY

Reena [Shetty.sup.*] [1], Kenneth J. Curry [1], and Barbara J. Smith [2], (1.) University of Southern Mississippi, Hattiesburg, MS 39406-5018 and (2.) Agricultural Research Service, Small Fruits Research, Poplarville, MS 39470-2005

Colletotrichum species infect strawberry plants and cause anthracnose. The focus of this study is the pre-infection and the early stages of infection. We have observed that lesions developed on the uppermost portion of the youngest petiole on plants sprayed with spores of Colletotrichum fragariae. We have observed a few fungal cells associated with early lesions and in extreme cases we have failed to find any fungal cells by serial sectioning. The appressoria observed in surface view are difficult to find in cross section. Some epidermal cells as seen in cross section within a lesion show a distinct pattern of granulation. We have not been able to confirm if this granulation pattern is correlated with the macroscopic dark lesions. Occasionally plant lesions in areas other than the youngest petiole have been observed. Preliminary evidence suggests that most spores on most areas of otherwise susceptible plants do not germinate. Occasionally a germ tube or immature appressorium is observed which suggests that f urther study is warranted. There is an increasing body of evidence that many fungi previously thought to be strictly saprophytic or pathogenic might exist as symptomless endophytes. Endophytes are fungi that complete their life cycle within the host and remain symptomless during the vegetative phase of parasitism. This suggests that looking for Colletotrichum in an endophytic phase in strawberry would not be unreasonable.

11:30 TROPHIC RELATIONS OF COLLETOTRICHUM ACUTATUM AND C. FRAGARIAE IN STRAWBERRY (FRAGARIA X ANANASSA)

Maritza [Abril.sup.*] [1], Kenneth J. Curry [1], and Barbara J. Smith [2], (1.) University of Southern Mississippi, Hattiesburg, MS 39406-5018 and (2.) Agricultural Research Service, Small Fruits Research, Poplarville, MS 39470-2005

The plant pathogens, Colletotrichum acutatum and C. fragariae, both cause anthracnose disease in strawberry plants. Collectotrichum acutatum is found worldwide and is increasingly important as the cause of strawberry petiole, stolon, and anthracnose fruit rot. Colletotrichum fragariae is often associated with anthracnose crown rot in strawberry and seems to be restricted to the southeastern United States. Using light and electron microscopy the ontogeny of the infection process on petioles and stolons by both pathogens on the 'Chandler' strawberry cultivar were observed. Previous studies suggested that C. fragariae might be hemibiotrophic (obtaining nutrients from living cells before becoming necrotrophic [obtaining its nutrients from host cells it had previously killed]) while C. acutatum was necrotrophic throughout its development. Bailey, O'Connell, Pring, and Nash(1992, Colletotrichum: Biology, Pathology, and Control, CAB International, pp. 88-120) predicted that species of Colletotrichum with a narrow h ost range, e.g., C. fragariae, were likely to be hemibiotrophs based on intimacy of host relationship while generalists such as C. acutatum would be necrotrophs. Parbery (1996, Biol. Rev. 71:473-527) postulated the trend of biotrophic fungi moving towards necrotrophy based on the expansion of food resources. Our exhaustive search of the host tissue infected by either fungus has indicated a very transient biotrophic phase for both C. fragariae and C. acutatum that barely fits the current concept of hemibiotrophy.

11:45 Divisional Poster Session

CHLOROSIS IN BRASSICA JUNCEA: AN ASSESSMENT OF PLANT TOLERANCE TO METAL POLLUTANTS IN SOIL

M.S. [Zaman.sup.*], Ketia L. Shumaker, and A.M. Powell, Alcorn State University, Alcorn State, MS 39096-7500

Phytoremediation, a green technology, uses vegetation to remove heavy metals or other pollutants from the environment. Phytoremediation depends upon identifying plant species that can tolerate and accumulate high concentrations of these pollutants. The purpose of this study was to investigate the tolerance of Brassica juncea (Indian Mustard) to various concentrations of cadmium (Cd) and lead (Pb) in soils. Plants were grown on soils containing various concentrations of Cd or Pb. Since chlorophyll is related to plant production, we studied the leaf chlorophyll concentrations on day 14 and 21 of plant life. On both days, dose related inhibition of chlorophyll a, chlorophyll b and total chlorophyll concentrations were observed in several Cd and Pb treated groups. Since this plant species showed tolerance to high concentrations of Cd and Pb in soils, it may be useful for phytoremediation studies. Investigations are being conducted in our laboratory to explore the hyperaccumulation potential of Brassica juncea fo r soil Cd and Pb.

PERCEPTIONS OF LOGGERS REGARDING SAFETY PRACTICES AND INJURIES IN MISSISSIPPI

Carey L. [Ford.sup.*] and Kerrex A. Taylor, Alcorn State University, Alcorn State, MS 39096

Logging in Mississippi is one of the most dangerous occupations in the private sector. Over sixty thousand Mississippians are directly employed in the forestry industry throughout the state. In 1995, the total forest industry impact on the state's economy was over 11 billion dollars. The purpose of this study was to determine the safety practices and types of injuries among loggers in Mississippi. The objectives were to: 1) determine the demographic characteristics of loggers in Mississippi; 2) determine among loggers the safety practices used in harvesting of hardwood and softwood timber; 3) determine among loggers the number and type of injuries sustained in logging; and 4) determine among loggers the effectiveness of safety classes taught by the Mississippi Cooperative Extension Service. Some of the major findings were: 1) the average age of loggers was 45 years and nearly 29% had less than a high school education; 2) a logging operation averaged 4.2 persons; 3) seventy-three percent of the respondents ow ned their own business; 4) the most frequent accidents among loggers were slips and falls which was 55% of the accidents reported in 1999. Recommendations were: 1) to continue providing safety training programs to educate all persons involved in the logging industry; and 2) safety training modules used by the MCES should include more practical applications and demonstrations to better enable loggers to understand the safety practices and concepts.

THE DETERMINATION OF DIURON IN CATFISH BY HPLC WITH UV-VIS DETECTION

Henry E. [Outlaw.sup.*] and Ernest L. Brothers, Delta State University, Cleveland, MS 38733

A concern among catfish farmers is the "off-flavor" produced by the blue-green algae, which blooms on the ponds during the spring and summer months. Two chemical by-products released by the blue-green algae are Geosmin (GEO) and methylisoborenol (MIB). These chemicals give catfish an earthy or dirt, like taste. When this occurs, catfish is said to have "off-flavor." In order to combat this problem, research is being conducted on the use of a phenyl urea herbicide called Diuron to control the blue-green algae. Diuron currently has an emergency tolerance level for combined residues at 2.0 ppm on catfish. This emergency tolerance level was established by the Environmental Protection Agency (EPA). If the tolerance level is approved for continued use, an effective and consistent method for determining the residue levels of Diuron on catfish and other matrices will be needed. This method looks at determining Diuron in catfish fillets by Accelerated Solvent Extraction (ASE), Liquid-Liquid Partitioning, and detectio n by HPLC with UV-VIS detection.

OBSERVATION OF EARLY INFECTION OF STRAWBERRY BY COLLETOTRICHUM FRAGARIAE

Jana B. Avant [1], Kenneth J. [Curry.sup.*] [1], and Barbara J. Smith [2], (1.) University of Southern Mississippi, Hattiesburg, MS 39406-5018 and (2.) Agricultural Research Service, Small Fruits Research, Poplarville, MS 39470-2005

Anthracnose of strawberry, notable by dark sunken lesions, is a disease caused by several Colletotrichum spp. including C. fragariae. Penetration of stolons by C. fragariae is accomplished by a penetration peg which develops from an appresorium. Once inside the host the penetration peg develops into hyphae that infiltrates the host tissue. The initial invasive hyphae maintain intimate contact with the host wall and perhaps the host plasmalemma. The interaction with the host is crucial for the success of the pathogen, especially an interaction that avoids host defense activation. Several plant pathogens have been found to mask or modify potential elicitors, such as chitin normally present within fungal walls, perhaps to avoid host defenses, such as chitinase. The distribution of chitin in strategic fungal structures, i.e., conidia, germ tubes, appressoria, penetration pegs, and initial invasive hyphae, can be identified with a lectin probe. Strawberry cultivar 'Chandler' was inoculated with C. fragariae CF-63 , incubated, and observed for the development of anthracnose symptoms. At appropriate stages, infected plant material was fixed and epoxy embedded. Embedded material was sectioned for light microscopy. Few or no fungal cells were found in early lesions. Further study with electron microscopy often revealed stressed host cells in the absence of fungal cells. When fungi were observed they were found more often within cortical tissue than epidermal and subepidermal tissues. Preliminary observations indicate that initial invasive hyphae apparently have less chitin than conidia, germ tubes, and older hyphal cells as measured by relative quantity of probe.

CADMIUM ACCUMULATION BY SESBANIA EXALTATA DURING PHYTOEXTRACTION

Ketia L. [Shumaker.sup.*], Jennifer Ntoni, Susmita Ghosh, and Charles Rhyne, Jackson State University, Jackson, MS 39217

Phytoremediation or green remediation is the use of plants to remediate sites contaminated by heavy metals, which is promising to be cost effective. This study focused on accumulation and the effect of cadmium on Sesbania exaltata. A hydroponic system was used to grow the plants in Hoagland solution alternating with cadmium nitrate Cd[([NO.sub.3]).sub.2] solution. Sesbania exaltata was exposed to 2, 4, 5, 6, 8, 10, 25 and 50 mg/L of cadmium solution. Plants were allowed to grow for four weeks, after which they were harvested and separated into shoots and roots for further metal analysis. Sesbania exaltata showed significant reduction in height and biomass when exposed to Cd. The chlorophyll content of the plants was also reduced by Cd exposure. For a plant to be a hyperaccumulator, it has to be able to translocate the metal into harvestable parts. The highest tissue concentration of Cd in the shoots of S. exaltata was 526 mg/kg which shows its potential as a Cd hyperaccumulator.

INDUSTRIAL WASTEWATER EFFLUENTS EFFECT ON THE GENETIC ENDPOINTS IN VICIA FABA: DICHLOROMETHANE AND FORMALDEHYDE

Anita [Patlolla.sup.*] [1], Babu P. Patlolla [2], and B.S. Sekhon [1], (1.) Jackson State University, Jackson, MS 39217 and (2.) Alcorn State University, Alcorn State, MS 39096

This study was done to determine the effect of dichloromethane and formaldehyde, the industrial priority pollutants, on the genetic endpoints, Vicia faba seedlings were treated with the chemicals in a randomized block design with four replication. Two concentrations of each of the test chemicals were selected, i.e., 175 [micro]m and 1750 [micro]M of dichloromethane and 100 [micro]M and 1000 [micro]M of formaldehyde. Lateral roots with a length of 1-2 cm were treated with the chemicals for 2 h in the dark. The seedlings were transferred to distilled water for a 24 h recovery period and root tips were harvested after 2 h treatment with 0.05% colchicine. Root tip squashes were stained with feulgen stain and data was collected for mitotic index and chromosomal aberrations. Both dichloromethane and formaldehyde depress mitotic activity in the meristematic tissue of vicia faba root tips in dose-dependent manner. Depressing effect of 1750 AIM dichloromethane on mitotic index was significantly higher than 1000 AIM o f formaldehyde. Dichloromethane and formaldehyde produced significantly more chromosomal breaks than the controls and their effect was dose-dependent. Dichloromethane at both concentrations produced more chromosomal breaks than formaldehyde. Considering total chromosomal aberrations the effect of both chemicals was dose-dependent and dichloromethane being more toxic than formaldehyde. Supported by Department of Education grant # P031B44000-95

EFFECTS OF EDTA ON THE PHYTOEXTRACTION OF LEAD FROM A CONTAMINATED SOIL USING COFFEEWEED (SESBANIA EXALTATA RAF.)

G.B. [Begonia.sup.*], M.F.T. Begonia, G. Miller, E. [Dillon.sup.*], and O. Ighoavodha, Jackson State University, Jackson, MS 39217

This study was conducted at the Jackson State University greenhouse to evaluate whether the addition of a synthetic chelate, ethylenediaminetetraacetic acid (EDTA), can further enhance the effectiveness of coffeeweed (Sesbania exaltata Raf.) as a phytoextraction species. Coffeeweed seeds were grown in various concentrations of lead (Pb) and EDTA mixed with a growing medium composed of sieved soil, peat, and sand (4:2:1, v:v:v). After six weeks of growth, the plants were harvested and their Pb contents were extracted using a modified nitric acid-hydrogen peroxide digestion technique. Lead concentrations were quantified by atomic absorption spectrophotometry. Results showed that coffeeweed can tolerate soil Pb levels up to 2000 ppm and that EDTA can significantly enhance the uptake of Pb by both the roots and the shoots. The results further demonstrated that pre-planting application of EDTA caused a greater Pb uptake by the plant compared to the untreated control and plants that were amended with EDTA one week before harvest.

PHYTOEXTRACTION OF LEAD FROM CONTAMINATED SOILS USING WHEAT: ROLE OF A SYNTHETIC CHELATE

M.F.T. [Begonia.sup.*], G.B. Begonia, K. Seals, A. [Butler.sup.*], R. Warren, and M. Burrell, Jackson State University, Jackson, MS 39217

Preliminary studies indicated that wheat (Triticum aestivum L.) can tolerate and accumulate significant amounts of lead (Pb) in its shoots when grown in Pb-amended sand. To further evaluate the potential of wheat for phytoextraction, a study was conducted to determine whether the timing of ethylenediaminetetraacetic acid (EDTA) application and acetic acid amendment can further enhance the shoot uptake of Pb. Two seeds were planted in each 150 ml super cell containing top soil and peat (2:1, v:v) amended with various levels of Pb and EDTA. Results revealed that wheat plants can tolerate toxic Pb concentrations as evidenced by the non-significant differences in shoot and root biomass among treatments. An exception to this general observation was the root inhibition of plants grown in 2000 ppm Pb that was amended with EDTA and acetic acid one week before harvest. Generally, root and shoot Pb uptake increased with increasing concentrations of soil-applied Pb. When no EDTA was added to the growth medium, the majo rity of the Pb was retained in the roots. However, when EDTA was applied one week before harvest, there was an enhanced Pb translocation to the shoots. Application of acetic acid in conjunction with EDTA led to a tremendous increase in shoot Pb uptake.

CHELATE-INDUCED PHYTOEXTRACTION OF LEAD FROM CONTAMINATED SOILS USING TALL FESCUE (FESTUCA ARUNDINACEA)

M.F.T. [Begonia.sup.*], G.B. Begonia, M. [Ighoavodha.sup.*], O. Okuyiga-Ezem, and B. Crudup, Jackson State University, Jackson, MS 39217

Tall fescue (Festuca arundinacea cv. 'Spirit') had been found to tolerate and accumulate substantial amounts of lead (Pb) in its shoots when grown in Pb amended sand. To further evaluate the suitability of tall fescue for phytoextraction, a study was conducted to determine whether the timing of ethylenediaminetetraacetic acid (EDTA) application and acetic acid amendment can further enhance the shoot uptake of Pb. Seeds were planted in 1.9 L plastic pots containing top soil, peat, and sand (4:2:1, v:v:v) amended with various levels of Pb and EDTA. Generally, root and shoot growth of tall fescue were not significantly affected at the two lower Pb levels, but were inhibited at the two higher Pb treatments with preplanting EDTA amendments. EDTA significantly increased shoot Pb uptake. However, there was no difference in Pb uptake whether EDTA was applied before planting or a week before harvest. Addition of acetic acid to the growing medium one week before harvest, further enhanced shoot and root Pb uptake only in plants grown at 1000 ppm Pb.

RESPONSE OF CHINESE MELON (MOMORDICA CHARANTIA L.) TO DIFFERENT TRELLIS SYSTEMS AND MULCHES

O.P. [Vadhwa.sup.*] [1], C.R. Reddy [1], and James M. Spiers [2], (1.) Alcorn State University, Alcorn State, MS 39096 and (2.) USDA small Fruit Research Station, Poplarville, MS 39470

Chinese melon (Momordica charantia L.) yield as influenced by four trellis systems and five different mulching treatments was evaluated. Chinese melon seeds of cultivar Durga an Indian variety were used for trellis systems study and planted on June 2, 1999. Chinese melon plants grown without trellis (control) were the least productive. Maximum yield was obtained with V-shaped trellis system followed by vertical and semi-vertical trellis systems. Harvesting was more convenient with all trellis systems as compared to control where the plants were allowed to trail and spread on the ground. First harvest date was July 23, 1999(50 days after transplanting) and final harvest date was October 25, 1999 (144 days after transplanting). Chinese melon seeds of an introduction from India were used for mulching study and planted on May 18, 1999. All plants were grown on a vertical trellis system. All mulching treatments were equally effective for the total yield compared to control (no mulch). However, for greater total y ield, hay, weed barrier and black plastic were superior to Kenaf mart. Kenaf mart did not differ from control. It was apparent that yield increased with time, peaked in October, and started declining in November. First harvest date was August 5, 1999 (77 days after transplanting and final harvest date was November 6, 1999 (171 days after transplanting).

AN ANALYSIS OF POTENTIAL MARKET OUTLETS AND MARKETING OPPORTUNITIES FOR SMALL-SCALE ECHINACEA PRODUCERS

Robin [Case.sup.*] [1], Kimberly Jones [1], Cassandra Williams [1], Liang C. Huam [1], and Allyson Best [2], (1.) Alcorn State University, Alcorn State, MS 39096 and (2.) University of Mississippi, University, MS 38677

Trends toward alternative medicine and natural healing have increased the interest in Echinacea cultivation in the U.S. Echinacea was the top selling medicinal herb in 1997, accounting for almost 300 million dollars in consumer herb sales. Marketing of Echinacea products have increased significantly in the last ten years as more consumers discover the medicinal benefits associated with their use. The actual size of the Echinacea product market and its marketing network are unknown, as it has only recently been commercialized for mass production. For small producers to grow the crop profitably, information on market outlets and opportunities must be clearly identified and made available for potential growers. Unlike traditional cash crops where markets have been established, the marketing of herbs, such as Echinacea, requires growers to research the markets, identify major buyers, and determine how to market their product. The purpose of this study is to explore market options that are currently available to small-scale producers by identifying existing distribution network and market outlets, including opportunities available for small producers. Data for this study was obtained from a market survey conducted by the University of Mississippi in 2000. Preliminary results indicate that marketing channels where farmers can sell their products depend on production volume, quality of raw products, consistency of supply, and ability to do contract farming with processors or buyers.

AN ECONOMIC EVALUATION OF ECHINACEA AS A POTENTIAL SMALL FARM CROP

Liang C. [Huam.sup.*], Patrick E. Igbokwe, and Robin Walker, Alcorn State University, Alcorn State, MS 39096

Increasing the economic viability of small farms requires operators to search for high value alternative crops. One such alternative to the traditional crops is Echinacea, which has achieved worldwide popularity for its antiviral properties. While demand for Echinacea products has increased, little economic and production information are available locally. Specifically, little is known about the economic returns and costs associated with small-scale cultivation of this crop. The objective of this study is to evaluate and compare the profit margins of two Echinacea crop species (E. purpurea and E. angustifolia) that are adaptable to local climatic conditions. Production data for this study was collected from a field experiment conducted at Alcorn State University over a period of two growing seasons. Preliminary results suggest that both species of Echinacea are economically viable; however, E. purpurea has higher root yield than E. angustifolia. Both species of Echinacea show positive gross margins with a tw o-season crop cycle.

FRIDAY AFTERNOON

Imperial Room

1:15 THE HOST-PATHOGEN RELATIONSHIP BETWEEN CERCOSPORELLA RUBI AND BLACKBERRY CULTIVAR 'SHAWNEE' (RUBUS SP.)

Melinda R. [Lyman.sup.*] [1], Kenneth J. Curry [1], and Barbara J. Smith [2], (1.) University of Southern Mississippi, Hattiesburg, MS 39406-5018 and (2.) Agricultural Research Service, Small Fruits Research, Poplarville, MS 39470-2005

The mechanism C. rubi uses to obtain nutrients from blackberry may be both saprophytic and parasitic. Cercosporella rubi is present from the time floral differentiation is initiated until mature flowers become senescent. Throughout floral development, hyphae are dense in crevices among carpels, stamens, petals, and sepals. Host cells appear healthy although hyphae, sheathed by a matrix, are closely appressed to the epidermis. Uninjured host cells would be expected since penetration structures have not been observed. Cercosporella rubi might absorb plant exudates from the surface of floral organs. Accumulation of exudates within crevices would provide an explanation of why more hyphae are found in crevices. In addition, C. rubi might take advantage of moribund tissue. Two ovules are produced during ovary development. One ovule naturally aborts at some point during development. Hyphae are found surrounding the deteriorating ovule and within collapsed tissue. These observations suggest that C. rubi expresses a saprophytic phase. Healthy carpels appear further along in development than infected carpels on floral buds of the same diameter. This may be due to hyphae interfering with suture closure during carpel development. Cercosporella rubi might be accelerating senescence by curtailing floral development. These observations suggest that C. rubi is expressing both parasitic and pathogenic phases.

1:30 PESTICIDE UPTAKE IS AFFECTED BY PLANT GROWTH STATUS

Joseph M. Wahome, William C. Mahone, and Roderick [Bailey.sup.*], Mississippi Valley State University, Itta Bena, MS 38941

Bean and pea plants grown under controlled conditions were challenged with an organophosphate pesticide at various stages of growth. Pesticide residues were extracted from roots, stems and leaves and analyzed using High Performance Liquid Chromatography. Both plant species accumulated pesticides. The level of accumulation peaked at the maximum growth phase. These findings will be discussed in view of bioremediation and evaluation of food webs and food chains.

1:45 LEAD CONTAMINATION IN URBAN SOILS: DETECTION AND REMEDIATION STRATEGIES

Jennifer [McDonald.sup.*], Kawana Alexander, Susmita Ghosh, and Charles Rhyne, Jackson State University, Jackson, MS 39217

Lead contamination in urban soil is a severe problem in many cities. Lead containing paint, for instance, often falls into urban soils near homes on which it was applied until the mid-1970s. After selecting possible sites for lead contamination, soil, plant and paint samples were taken from various vacant lots on Pearl Street, Jackson, MS. The samples were dried in an oven at 1000[degrees]C for 24 hours, ground and tested for lead by using a Niton XRF (X-ray fluorescence) instrument. Of the 28 samples taken, several soil samples had higher than 500 ppm of lead with the highest of 6384 ppm. The highest amount of lead was found at 30 cms away from the foundation where the primary source was fallen paint chips. Lead in plant samples from around the house was found to be below detection levels. Phytoremediation was also studied in the lab as a possible remediation strategy.

2:00 SCREENING FOR LEAD HYPERACCUMULATORS IN PHYTOREMEDIATION STUDY

Nyki [Preacely.sup.*], Aaron L. Jackson, Susmita Ghosh, and Charles Rhyne, Jackson State University, Jackson, MS 39217

Phytoremediation is a natural process carried out by plants, especially those that have been able to survive in contaminated soil and water. Plants constitute 99% of all living mass (biomass) on earth and may serve as major sinks for heavy metals released into the environment. Our research objective is based on surveying and identifying wide-ranging plant species as potential hyperaccumulators. A modified hydroponic growing system was used to suspend plants in aqueous solutions of either Hoagland's nutrient medium or varying concentrations of lead nitrate, Pb[([NO.dub.3]).sub.2]. Plants were exposed to Pb concentrations of 50-500 mg/liter of Pb. After three weeks of Pb exposure, plants were harvested and separated into shoots and roots to analyze the accumulations of Pb. Among the ten different plant species tested, three species of mint (Mentha spicata, M gracilis, and M. suaveolens) and two varieties of tropical spinach (Basella rubra) showed high potential as Pb hyperaccumulators. The height and biomass of the plants were also observed.

2:15 MATHEMATICAL MODELING OF LEAD PHYTOREMEDIATION AND WEB DESIGN

Debmallo Shayon [Ghosh.sup.*], Susmita Ghosh, Charles Rhyne, and Kunal Ghosh, Jackson State University, Jackson, MS 39217

The problem of lead contamination is a severe one in soil and water in many areas. Some plants, named hyperaccumulators, take up lead in large amounts. However, it is difficult to determine how much lead a plant will accumulate. Each plant's lead uptake depends on the lead concentration in the growth medium, but in exactly what relation is hard to calculate. First part of the purpose of the project is to write a computer program that calculates this relation. Much of the preliminary work, such as the plotting of basic regression lines, was accomplished using Microsoft Excel 2000. The actual program was completed in FORTRAN and written and compiled on a Jackson State University server. Data from Ipomoea lacunosa, Sesbania exaltata, and Triticum aestivum was used. The second part of this project involved the creation of a web page about the Jackson State University phytoremediation program, basically an Internet-based unified database of information about phytoremediation. This project was completed using Micr osoft FrontPage 2000 as a design tool and a HTML editor. Both of these projects will, hopefully, help the growing field of phytoremediation.

2:30 Break

2:45 A NOVEL AND RAPID METHOD FOR ANALYSIS OF NUTRIENT UPTAKE BY THE PLANTS BY USING ION SELECTIVE ELECTRODES

Mudlagiri B. Goli, Nicole Harris, and Brian [Smith.sup.*], Mississippi Valley State University, Itta Bena, MS 38941

It is a well-known fact that for chemists, it is not easy to perform the research without an access to instruments like GC, HPLC, AA, Spectrophotometers, NMR, etc. Even if you have some of them it is difficult and a costly affair to keep them updated and running. Many of these instruments are highly technical, trouble prone, accident prone and are beyond the reach of pocket books of many schools. And important thing is one has to generate a lot of chemical waste like in HPLC methods. To analyze a few samples we are forced to create a large amount of liquid waste. Many schools are not in a position to handle the generated waste. Keeping that in mind, we planned to develop a method that is, user friendly, less technical, rapid, no waste generator and reliable. We saw the possibility of that in ion selective electrodes and in other probes. We have studied a biological system. The author's (mbg) familiarity with the lemon grass, a grass good to have in your back yard led him to use it as a system. We planted 12 + 12 = 24 of that grass in the green house starting from September 8, 2000. After one month of planting, the plants were separated into two groups. One group was treated with various amounts of calcium nitrate. Similarly the other group was treated with ammonium nitrate in equi-molar amount of nitrate ions. In retrospect that is like ammonium to calcium = 2:1 ratio. The plants were allowed to grow for 16 more days before they were cut down and analyzed for [Ca.sup.+2], [[NH.sup.+1].sub.4] [[NO.sup.-1].sub.3], [Cl.sup.-1] and total dissolved solids. The analysis of uptake of chemicals by the plant will be discussed. These readings are surely interesting and helpful in studying the effect of fertilizers on the growth of the plants.

3:00 A NOVEL AND RAPID METHOD FOR ANALYSIS OF THE MICRONUTRIENTS PRESENT IN VEGETABLES BY USING ION SELECTIVE ELECTRODES (ISE)

Mudlagiri B. Goli, Mississippi Valley State University, Itta Bena, MS 38941

As stated in our earlier paper, our attempt of studying the nutrient uptake by the plants and the analysis of chemicals by Ion Selective Electrodes (ISE) was a success. That led us to apply this ISE method to other plant products, vegetables. So far we have analyzed the green beans and black eyed peas for [Ca.sup.+2], [[NH.sup.+1].sub.4], [[NO.sup.-1].sub.3], [Cl.sup.-1] and total dissolved solid. The analysis was carried out in duplicates. The numbers are reproducible and give us a significant insight into the chemical compositions of many of those ions in the vegetables. We have a plan to study the other vegetables too. We want to thank Vernier Software & Technology for providing us with the valuable tool, the sensors and the interface, LabPro 2.0. We are not promoting any company. We just happened to have Vernier system in our laboratory. The author is fully responsible for the numbers quoted in here. The numbers to be quoted in the presentation are for scientific discussion only. More has to do be done b efore one can put them as nutrient values.

3:15 PHYTOREMEDIATION OF LEAD IN SOIL

William C. Mahone, Abul B. Kazi, Joseph M. Wahome, and Andrea [Cook.sup.*], Mississippi Valley State University, Itta Bena, MS 38941

Previous studies of pesticides with legumes "Lima Beans" have shown them to display vigorous transport and metabolic activity. Subsequent preliminary studies have indicated that they are capable of bio-accumulating lead from soil. Analysis of legumes, grown under exposure to soluble lead, was carried out by dry ashing, extraction, and flame AA techniques. Results of these studies will be discussed.

3:30 BLOOM THINNER WILTHIN DECREASED FRUIT SET AND INCREASED FRUIT YIELD AND QUALITY OF THREE APPLE CULTIVARS

Ejaz Ansari, Frank B. [Matta.sup.*], and Liaquat A. Khan, Mississippi State University, Mississippi State, MS 39762

Apple cultivars 'Royal Gala,' 'Blushing Gold,' and 'Ultra Gold Delicious' were sprayed with different concentrations of Wilthin. The trees were sprayed at eighty percent bloom. In 1997, fruit diameter of 'Royal Gala' was increased by 1.5% Wilthin. In 1998, all Wilthin concentrations increased fruit diameter. Fruit diameter of 'Ultra Gold' was increased by all concentrations of Wilthin in 1997 and 1998. Wilthin did not influence fruit diameter of 'Blushing Golden.' Wilthin decreased fruit set in all three apple cultivars. Fruit yield, length, and firmness was increased by Wilthin and the response was concentration and cultivar dependent. In general, Wilthin increased soluble solids concentration (SSC), individual sugars, and reduced fruit juice acidity of all cultivars.

3:45 THE ROLE OF FATTY ACID CONTENT IN PECAN COLD HARDINESS

Jeb [Cade.sup.*] and Frank B. Matta, Mississippi State University, Mississippi State, MS 39762

A two-year study (1998-99 and 1999-2000) was conducted to determine the relationship between fatty acid content and pecan cold hardiness. Cultivars evaluated were 'Jackson' and 'Owens.' The predominant fatty acids were linolenic (18:3), linoleic (18:2), oleic (18:1), stearic (18:0), and palmitic (16:0). In both cultivars, total saturated fatty acid content was negatively correlated with cold hardiness and negatively correlated with unsaturated fatty acid content. Total unsaturated fatty acid content was positively correlated with cold hardiness. In 'Owens,' 18:2 was significantly correlated with cold hardiness and total saturated fatty acid content. The findings were similar both years, indicating a strong relationship between fatty acid content and cold hardiness.

4:00 Divisional Business Meeting
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Publication:Journal of the Mississippi Academy of Sciences
Geographic Code:1USA
Date:Jan 1, 2001
Words:7170
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