Agriculture and plant science.

Chair: William Kingery, Mississippi State University 

Vice-chair: Evelin J. Cuadra, Alcorn State University 

FRIDAY MORNING

Exhibit Hall B

8:30 GROWTH CONDITIONS AFFECT THE EXPRESSION OF INLB IN LISTERIA MONOCYTOGENES AND LISTERIA SPP 

Taejo Kim and Juan L. Silva*, Mississippi State University, Mississippi State, MS 39762

Listeria monocytogenes is a gram-positive, facultative intracellular bacterium that causes listeriosis in humans. The InlB, a 67-kDa surface and secreted protein, is essential for adhesion and mediates the invasion of L. monocytogenes into human endothelial cells. The objectives were to assess the effect of different growth conditions on expression of InlB in Listeria monocytogenes and Listeria spp. The InlB was quantitatively extracted in a solubilized form with 1 M Tris-HC1 at pH 7.5. SDS-polyacrylamide gel electrophoresis (PAGE) was done with 12% polyacrylamide gels and silver stained. The intensity of InlB bands was quantified using an Un-Scan-It software program. The InlB was easily identified as a distinct protein band of 67 k-Da in SDS extracts of L. monocytogenes and Listeria innocua. However, InlB was not detected in the extract of L. grayi. InlB expression of L. monocytogenes 19111 in TSB (183 pixels) as determined by band intensity was the highest than in LB (137 pixels) and BHI (173 pixels). All stationary phase culture cells (16 h) of L. monocytogenes 19115, 7644, and 19111 produced the highest amount of InlB, 116, 183, and 146 pixels, respectively. Based on this study, it could be speculated that growth conditions may influence the overall expression of InlB and thereby affect the pathogenicity of L. monocytogenes.

8:45 EXPRESSION OF 80 KILODALTON LISTERIA ADHESION PROTEIN IN LISTERIA MONOCYTOGENES AND LISTERIA SPP.

Juan L. Silva*, Bang-Yuan Chen, and Taejo Kim, Mississippi State University, Mississippi State, MS 39762

Adhesion and invasion of L. monocytogenes into epithelium cells are mediated by internalin A (Inl A), an 80 k-Da surface protein. In this study, the expression of Inl A in L. m. 19115, L. m. 19111, L. m. 7644, L. grayi and L. innocua was assessed. Inl A was extracted by treatment of bacteria with 1%(w/vol) SDS in 10mM tris-HC1 at pH 8.0. The extracted protein was washed by 90% acetone and dissolve in Laemmli buffer. SDS-PAGE was done by the method of Laemmli buffer with 12% polyacrylamide gels. For staining of the gels, a silver staining kit (Bio-Rad, Munich, Germany) was used. The gel was examed by UN-SCAN_IT gel (S.S.C. Verson5. 1). Inl A expression was only found in L. m. 19115 and L. grayi with band intensities at 76 and 58 pixel, respectively. Inl A was not detected in the extract of L. m. 19111, L. m. 7644, and L. innocua.

9:00 INFLUENCE OF COOKING METHOD ON MIB OFF-FLAVOR REDUCTION IN FARM RAISED CHANNEL CATFISH

Chonthida Kaewplang, William E. Holmes, Juan L. Silva*, and Taejo Kim, Mississippi State University, Mississippi State, MS 39762

Off-flavor is the most significant problem facing the catfish industry. Cyanobacteria and actinomycetes can produce geosmin (1,10-trans-dimethyl-trans-9-decalo) and MIB (2-methylisoborneol), (1,2,7,7-tetramethyl-exo-bicyclo [2,2,1] heptan-2-ol) which are impart unpleasant earthy/muddy taste and odor into the catfish. The objective of this experiment was to screen cooking methods for their effects on off-flavor reduction. The effect of cooking methods (microwaving, baking, frying, and marinating prior to baking) were studied for their ability to reduce the post-harvest off-flavors in catfish. Sensory evaluation based on intensity of off-flavor was performed utilizing a 5-point hedonic scale. The MIB was quantified in a GC utilizing a SPME procedure. The "frying" and "marinating prior to baking" methods were found to be effective in decreasing off-flavor in the catfish (MIB concentration reduced from 8.2 ppb to 1.2 ppb and 3.9 ppb, respectively). This reduction maybe due to compounds present in the marinating and/or breading.

9:15 EFFECT OF STORAGE TEMPERATURE ACCUMULATION ON QUALITY OF FRESH CHANNEL CATFISH FILLETS

Youkai Lu, Juan L. Silva*, and Taejo Kim, Mississippi State University, Mississippi State, MS 39762

Storage temperature has great influence to the growth of bacteria, hence the shelf life of fresh fish products during storage. The objective of this research was to study the role of storage temperature accumulation on bacterial growth pattern in catfish fillets during refrigerated storage. Fresh catfish fillets were packed in polythene bags and stored on top ofice (WI) or without ice (WI) under refrigeration. They were sampled periodically and analyzed for psychrotrophic bacteria (PPC). Also, ERTCO temperature sensors were used to monitor hourly storage temperature of packed catfish fillets. The temperatures of WO and WI fillets were 5.14 [+ or -] 0.39[degrees]C and 2.42 [+ or -] 0.78[degrees]C, respectively. When PPC reached 108CFU/g, hourly storage temperature accumulation were 405.8[degrees]C in WO fillets and 496.1[degrees]C in WI fillets. The correlation coefficients of storage temperature accumulation and PPC were higher than 0.8. Results indicate that temperature accumulation plays an important role on bacterial growth pattern on catfish fillets, but other temperature profiles such as magnitude and frequency of temperature fluctuation may also play significant roles on bacterial growth pattern and fresh catfish fillet quality during storage.

9:30 REDUCTION OF GEOSMIN AND 2-METHYLISOBORNEOL COMPOUNDS IN CATFISH FILLETS BY PURE LIME EXTRACT TREATMENT FOLLOWED BY LEMON PEPPER MARINATION

Sovann Kin, Juan L. Silva*, William E. Holmes, and Taejo Kim, Mississippi State University, Mississippi State, MS 39763

The effects of pure lime extract followed by lemon pepper marination on catfish fillet samples spiked with geosmin and 2-methylisoborneol compounds were assessed by a descriptive analysis panel and quantitatively by SPME-GC. The panelists were trained to evaluate the intensity of geosmin and 2-methylisoborneol compounds using Labeled Magnitude Scale (LMS). This consists of a vertical line with verbal labels (barely detectable, weak, moderate, strong, very strong and strongest imaginable) for intensity levels spaced in a quasi-logarithmic fashion. Sensory evaluation indicated that there was a reduction in MIB and geosmin off-flavors of treated samples compared with untreated samples. This suggests that both food-grade ingredients may be used to reduce/eliminate off-flavor compounds from catfish at some point after processing. These ingredients appear to mask and not to reduce/break down the off-flavors in the fish muscle. These ingredients can be added to a marinade or incorporated in an injection/tumbling solution after catfish fillets are processed.

9:45 THE STUDY OF OXIDATIVE STABILITY OF BIODIESEL AND THEIR FEEDSTOCKS

John McGillivray, Juan L. Silva*, and Rafael Hernandez, Mississippi State University, Mississippi State, MS 39762

The price of gasoline is rising and alternative fuels are now looked at as a solution to the rising prices. Fatty acid esters, more commonly called biodiesel, are transesterified vegetable oils and animal fats. Biodiesel made strictly from saturated animal fats will have cold flow problems, and biodiesel made strictly from unsaturated vegetable oils will be prone to autoxidation which will lead to oxidative rancidity and low-quality biodiesel. The objectives of this study were to examine alternative feedstocks for biodiesel production and measure the oxidative rancidity on these feedstocks caused by specific extraction procedures. Catfish and poultry waste streams were obtained from local processing plants and stored in the refrigerator. These two feedstocks along with ground soybeans were extracted using propane, hexane, and supercritical carbon dioxide. After extraction, the samples were tranesterified to form fatty acid methyl esters. The extent of oxidative rancidity was measured using the iodine value (IV), peroxide value (PV), oxidative stability index (OSI), thiobarbituric acid (TBA) and free fatty acids (FFA), anisidine value (AV), allylic position equivalents (APE), bis-allylic position equivalents (BAPE), and microbial plate count on standard plate count agar. Feedstock quality varied with source but the oils proved to be fairly stable to oxidative rancidity. The use of alternative feedstocks to produce biodiesel will expand the market and allow poultry and catfish producers to utilize their waste by-products.

10:00 INFLUENCE OF SANITATION TREATMENT AFTER HARVEST ON SHELF LIFE OF BLUEBERRIES IN MISSISSIPPI

Wei-Chun Chen, Juan L. Silva*, Jelena Stojanovic, and Taejo Kim, Mississippi State University, Mississippi State, MS 39762

More than one million kilograms of blueberries are produced each year in Mississippi. About 50 percent of Mississippi blueberries are sold wholesale through marketing. Extending shelf life of blueberries has become an important issue in the nation. The objective of this study was to evaluate different pretreatments on shelf life of machine-harvested blueberries in Mississippi. Machine picked blueberries were treated with different concentrations of chemical solutions: chlorine (100ppm, 200ppm), peracetic acid (25ppm, 50ppm), ethanol (20%, 70%), and distilled water (control) for 30s. After treatment, blueberries were drained, blot-dried by air and placed in plastic clamshells. Samples were stored at 2-4 Z in a refrigerator and evaluated after 0, 4, 6, 12, 16, 20, 24, and 30 days. Samples were evaluated for aerobic plate counts and yeasts and molds counts. Aerobic plate counts increased by 1.5 log and yeast and mold counts by 2 log after two weeks. Berries treated with chlorine and ethanol had lower counts than those treated with peracetic acid. Pretreatment in blueberries seem important in keeping the quality and increasing shelf-life of blueberries.

10:15 CHEMICAL AND QUALITY CHANGES OF SWEET POTATO ROOTS DURING SACCHAR-IFICATION PRETREATMENT WITH AND WITHOUT ADDED ENZYMES TO PRODUCE A SWEET POTATO BEVERAGE

Jelena Stojanovic and Juan L. Silva*, Mississippi State University, Mississippi State, MS 39762

Decreasing starch content of sweet potato (SP) would be crucial step in the processing of a beverage. Our objective was to use endogenous amylases and commercial enzyme mixes to increase sugar content of SP for the production of an acceptable beverage. Sweet potatoes were peeled, minced, mixed with water (75:25), heated and held at 70,,aC for 30 min. Samples were analyzed for total amylolytic activity, reducing sugars, PPO, soluble solids, alcohol insoluble solids, total phenolics and moisture every 10 minutes. The commercial fN-amylase plus glucoamylase mix was added to the blanched sweet potato slurry and incubated at 55,,aC for 30 min. The starch debranching enzyme pullulanase was not present. The process to hydrolyze starch using endogenous enzymes should be carried at 70,,aC for up to 20 min since it produces highest amount of reducing sugars (11g/100g). The PPO activity rapidly decreased in the first 10 min of the treatment thus minimizing browning of the slurry. The commercial enzyme preparation produced the highest amount of reducing sugars but was lower in lightness and hue. Thus, pretreatments of SP prior to extraction of juice can increase sugars and decrease starch thus adding value and new possibilities for the production of an acceptable beverage.

10:30 Break

10:45 EVALUATION OF DIFFERENT TYPES OF MULCHES FOR ORGANIC PRODUCTION OF CUCUMBER

Ravi Chinthakuntla (1*), Rao S. Mentreddy (2), Patrick Igbowke (1), Franklin D. Jackson (1), Frank B. Matta (3), O.U.K. Reddy (4), Molly Jahun (5), Louis Licata (1), and Smith D. Keltra (1), (1) Alcorn State University, Lorman, MS 39096, (2) Alabama A & M University, Normal, AL 35762; (3) Mississippi State University, Mississippi State, MS 39762, (4) West Virginia State University, Institute, WV 25112, and (5) Cornell University, Ithaca, NY 14853

Organic vegetable production is currently expanding at approximately 20% annually and organically produced vegetables fetch premium prices compared to conventionally produced vegetables. Organic production continues to be a small-scale niche-market enterprise as weeds are a major problem limiting its expansion. Various types of mulches have been shown to increase yields through less weeds, better soil moisture conservation and soil temperature regulation in organic production systems. A field trial was conducted therefore, on a Memphis silt loam soil during the 2005 growing season, with the objective of assessing mulching effects on cucumber in organic production system. The plots were arranged in a split-plot design with three mulching treatments: wood mulch, pine mulch, and control No mulch as the main plots and three cucumber varieties obtained from Cornell University, Ithaca, NY as the sub-plots. Each treatment was replicated three times. All varieties were evaluated for insect and disease resistance, and yield and fruit characteristics. Organic fertilizers (bone meal and blood meal) were applied, whereas insects and diseases were controlled with organic (Neem extraction ferti-lome) triple action. Mulching cucumber with wood chips or pine straw resulted in a total fruit yield of 35.5 and 33.0 kg/plant, respectively, compared to 26.6 kg/plant from control treatment. Among varieties both Market-more and Poinsett with an average of 4.7 kg/harvest produced a seasonal total yield of 15 kg/plant, whereas, Control plants produced about 9% lesser yield. In this study, mulching boosted the yield of cucumber by 29% over no mulch control.

11:00 UTILIZING RICE FLOUR TO ADD VALUE TO LOW-FAT CHICKEN NUGGETS

V. Jackson, Mark Schilling*, and P.C. Coggins, Mississippi State University, Mississippi State, MS 39762

The objective of this research was to add value to chicken nuggets by utilizing rice flour in the place of wheat flour to produce a low-fat, gluten-free product that can be consumed by individuals with celiacs disease. Raw chicken breast meat was coated in either a rice or wheat dry batter prior to dipping in whole egg, or dipped in rice or wheat wet batter. The breaded nuggets were then either heat processed by baking or frying. Nuggets from each treatment were evaluated for consumer acceptability, cooked color, shear force, moisture, crude fat, and protein content. A randomized complete block design with 3 replications and 6 treatments was utilized to examine the treatment effects (p<0.05) on chicken nugget quality. There was no difference (p>0.05) in consumer acceptability among the six treatments, and all treatments received an average score of like slightly. Consumers were separated into six different consumer clusters with varying chicken nugget preferences using agglomerative hierarchical clustering. Baked nuggets, (wheat and rice flour), had less (p<0.05) fat and more (p<0.05) protein than fried nuggets. Baking the nuggets reduced the lipid percentage from 30% to about 10% with no decrease in acceptability. Fat content was also lower (p<0.05) in nuggets coated in wet batter for both rice and wheat flour in comparison to those that were fried. This demonstrates the usability of rice flour in the formulation of low-fat chicken nuggets without diminishing quality and the added value component of usability by people with celiacs disease.

11:15 IMPROVED RICE IRRIGATION TECHNIQUE PROTECTS GROUND WATER SUPPLIES AND REDUCES NPS RUNOFF

Joni Cooks (1), Joseph H. Massey (1*), Cade Smith (1), Alton Johnson (2), Ashley Andrews (1), Jim Thomas (1), Phil Tacker (3), Shawn Lancaster (3), and Earl Vories (4), (1) Mississippi State University, Mississippi State, MS 39762, (2) Alcorn State University, Lorman, MS 39096, (3) University of Arkansas, Fayetteville, AR 72701 and (4) USDA ARS Portageville, MO 63873

Over the past two years, studies have been conducted at five rice farms located throughout the Mississippi Delta and parts of northeast Arkansas. The rice fields have been used as a way to examine typical farming techniques used by current rice farmers and introducing them to a more environmentally friendly way to supply water to their fields. Farmers were introduced to an intermittent method of watering which allowed for breaks in watering instead of their typical continuous flooding of the fields. As the watering methods being the only variable between different rice paddies, research has found no difference in rice yields when using the intermittent flooding technique. However, water use was decreased by 30% over continuous flooding. Capture of rainfall was increased by approximately 70%, reducing non-point source runoff from the fields by approximately 50%. Adoption of intermittent rice irrigation would help to protect ground water supplies being used to irrigate most farms in this region.

11:30 Divisional Poster Session

CHELATE-INDUCED SOLUBILITY OF METAL ENHANCES PHYTO-EXTRACTION OF CADMIUM-CONTAMINATED SOILS BY WHEAT (TRITICUM AESTIVUM L.)

Jennifer Ntoni*, Maria F. Begonia, Gregorio B. Begonia, Oscar Hundley, Tyronza Lee, and Darla Gilliard, Jackson State University, Jackson, MS 39217

Phytoextraction is gaining acceptance as a cost-effective and environmentally friendly phytoremediation strategy for reducing toxic metal levels from contaminated soils. Cognizant of the potential of this phytoremediation technique as an alternative to expensive, engineering-based remediation technologies, this study was conducted to determine whether the addition of synthetic chelates can further enhance the shoot uptake of cadmium (Cd). Seeds were planted in plastic tubes containing top soil and peat (2:1, v:v) spiked with various levels (0, 250, 500 mg Cd/kg dry soil) of cadmium nitrate. At seven weeks after emergence, aqueous solutions of EGTA and acetic acid were applied to the root zone, and plants were harvested at 0, 5, and 7 days after chelate addition. Results revealed that wheat was relatively tolerant to moderate levels of Cd as shown by non-significant differences in root and shoot biomass among treatments. Root Cd concentration increased with increasing level of soil-applied Cd. Further increases in root Cd were attributed to chelate amendments. Translocation index, which is a measure of the partitioning of the metal to the shoots, was significantly enhanced with chelate addition especially when both EDTA and acetic acid were used. Maximum translocation index occurred at 5 days after chelate addition. This observation coincided with the time when maximum amounts of Cd were bioavailable in the soil solution as shown in a corollary chelate-induced metal solubility study.

PHYTOREMEDIATION OF RDX AND TNT CONTAMINATED SOILS USING NATIVE GRASSES

A frachanna Butler (1,2*), Victor Medina (2), and Maria F. Begonia (1), (1) Jackson State University, Jackson, MS 39217 and (2) US Army Engineer Research and Development Center, Vicksburg, MS, 39180

Firing range contamination and sustainability are major issues for the United States military. Munition and firing range test sites operate throughout the U.S. and beyond covering acres of land and water. Munitions fired, dropped, and disposed of on those ranges have become harmful to its environment. The chemical constituents and by-products of those munitions pose a toxic threat to public health and natural ecosystems as they move through its natural surroundings. The commonly used explosives, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and trinitrotoluene (TNT) are often found in soil and groundwater from military firing ranges. Because continued training with live ammunition is still needed, the cleanup of these contaminants may prove to be expensive. Also, the application of environmental maintenance designed to support other uses could interfere with routine training and testing operations. To avoid high cost and site interferences, one alternative being considered to manage military firing ranges is the use of native grasses via phytoremediation. Phytoremediation uses living plants for in situ and ex situ remediation of contaminated soil, sludges, sediments and ground water, and is a promising biotechnology for cleanup of contaminated sites. It has been indicated in other studies that phytoremediation is effective which concludes that it could be a useful approach at active firing ranges. Our research evaluates the biological removal and physical stabilization of RDX and TNT contaminated soils with the addition of Cyperus esculentus (Yellow nutsedge). Lysimeters were designed to assimilate natural rainfall to allow for the collection of leachate flowing through the soil as well as runoff from the soil surface. The anticipated result of this research is to stabilize the contaminants and reduce the amount of RDX and TNT in the soil surface runoff and leachate.

SEED TREATMENTS VS. IN-FURROW TREATMENTS FOR NEMATODE, INSECT, AND FUNGI CONTROL

Julie Anna Blessitt* and Gabe L. Sciumbato, Delta Research and Extension Center, Mississippi State University, Stoneville, MS 38776

Insecticide, nematicide, and fungicide seed treatments were compared to the performance of insecticide, nematicide, and fungicide applied in-furrow. Eight trials were planted in DP 444 BG/RR at 4 seed/row ft on multiple dates and in multiple locations. Seedling survival two and four weeks after planting; thrip counts at three and six weeks after planting; reniform nematode populations at planting, midseason, and at harvest; and yield were collected for each trial. Reproductive factors for reniform populations were calculated for comparison. Results will show if seed treatments perform comparative to in-furrow applications of insecticides, nematicides, and fungicides. Few differences were seen in individual trials on any data collected. There were also few significant differences across all trials and locations.

THE DEVELOPMENT OF A GENOMIC LIBRARY OF PINUS TAEDA

Annita Avery (1*), Daniel Peterson (2), Zenaida V. Magbanua (2), Dipaloke Mukherjee (2), and Supaphan Thummasuwan (2), (1) Tougaloo College, Tougaloo, MS 39174 and (2) Mississippi State University, Mississippi State, MS 39762

Loblolly pines (Pinus taeda) have other common names including old-field pine, bull pine, and rosemary pine. Loblolly pine is important to the economics of the southeast United States because it makes up half of the total wood production and about 80% of pine seed production for the Unite States. Loblolly pine is also a source of renewable fiber, lumber, biofuel, paper, shade, etc. Loblolly pines grow in wet, low places, and are cold to lerant. The present study of loblolly Pine is in its infancy stage; however, a DNA library was developed to study structure, specific trait, genes, pharmaceutical, and economic value and to find specific gene functions for genetic engineering. We isolated DNA from loblolly pine, and dA re-sidue was added to each fragmented 5' end. pGEM plasmid vector was linearized and a single dT re-sidue was added to each 3' end. Ampicillin was the plasmid's antibiotic resistance gene and lacZ was the reporter gene. E. coliu was transformed with the resulting Loblolly pine DNA pieces. The colonies were picked using a Q-pix2 picking robot. Future steps are to sequence the clones and analyze the sequence for genes. This project supported by the Mississippi Functional Genomics Network.

MYROTHECIUM VERRUCARIA'S EFFECTIVE ABILITY AS A BIOHERBICAL AGENT AGAINST MORNINGGLORY (IPOMOEA) SPECIES

T. McCallister (1*), R.E. Hoagland (2), C.D. Boyette (2), M.A. Weaver (2), and Rachel Beecham (1), (1) Mississippi Valley State University, Itta Bena, MS 38941 and (2) USDA-ARS, SWSRU, Stoneville, 39776

(MV) is an experimental bioherbicide which has been studied on numerous weeds ranging from kuduz to morning-glories. Along with the original strand of MV, an organosilicon surfactant (Silwet L-77) and an invert emulsion were added to the original strand. Selections of morningglories were chosen for the experiment. The species were grown to the first-second leaf stage. At that growth period MV spores were prepared in a mixture of Silwet L-77 or an invert emulsion. The species were sprayed with MV, invert emulsion, or a MV plus an invert emulsion mix. After the application of the fungal mixtures the species were placed in the dew chamber for 15-18 hours and later moved to the greenhouse. The damage of MV was assessed and further tests were conducted to determine more biological reactions to the fungus. Chlorophyll analysis as well as biomass reductions were also conducted. Ivyleaf, moonvine, and palm-leaf morningglories were quite tolerant to the MV, while pitted, multi-color, moonflower, and cypressvine showed extreme injury. MV alone may be tolerant by several species but coupled with an invert emulsion can increase its potency. The invert emulsion plus MV increased the damage to moonvine over just MV. The results of the greenhouse study shows that there are great differences between the bioherbicidal ability to suppress the weeds but used with an invert emulsion may provide to be an effective agent against the bothersome weeds, morningglories (Ipomoea) species in some cases.

THE EFFECT OF THE HERBICIDE GLUFOSINATE ON SOIL BIOLOGICAL ACTIVITY

Kamalesh Thanappan (1*), Robert .M. Zablotowicz (2), Krishna N. Reddy (2), and Joseph Wahome (1), (1) Mississippi Valley State University, Itta Bena, Mississippi 38941 and (2) USDA-ARS, Southern Weed Science Research Unit, Stoneville, Mississippi 38776

Glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] is a derivative of a natural product used as a nonselective herbicide. Transgenic crops resistant to glufosinate have been released and the use of this compound is expected to increase dramatically, thus a need to understand the environmental effects of this compound. The studies were conducted to assess glufosinate effects on soil biological processes as a component of evaluating risks associated with use of this herbicide. The effects of glufosinate on soil respiration, alkaline phosphatase activity and fluorescein diacetate (FDA) hydrolytic (esterase and lipase) activity were assessed in conventional tilled (CT) and no-tilled (NT) Dundee silt loam soil. Soil was treated with glufosinate at 0, 0.83, 1.66 and 3.22 kg ha-1 rates or non-treated. In the NT soil all glufosinate rates increased soil respiratory activity (~ 18%) during 7-day incubation, however glufosinate had no effect in CT soil. All rates of glufosinate reduced FDA hydrolysis in NT soil for only 24 h, while in CT soil FDA activity was significantly reduced for 96 h. Soil phosphatase activity was increased by the two lower rates of glufosinate. Minor detrimental effects of glufosinate on soil biological activity were observed and certain processes such as phosphatase and respiration were actually increased by glufosinate.

GENERATION OF LOBLOLLY PINE DNA LIBRARY

LaShonda Robertson* and Daniel Peterson, Tougaloo College, Tougaloo, MS 39174 and Mississippi State University, Mississippi State, MS 39762

Loblolly pine is classified in several ways. It is in the plant kingdom and in the division of Coniferophyta, the class of Pinopsida and family of Pinace. It is one of the pines native to the southeastern United States. Loblollies are disease resistant, drought resistant, and cold tolerant. Loblolly pines are sometimes called Oldfield pine because they have a rapid growth rate; Bull pine because it is often large in size; and Rosemary pine because it has a distinctive fragrance. Loblolly pine is the model gymnosperm because there is more genetic information for Loblolly pine than for any other gymnosperm. In order to investigate the genomic structure of Loblolly pine DNA we worked on creating a Loblolly pine DNA Library. DNA was isolated from pine needles and sheared to produce 1-2 kb residues. The size of the sheared DNA was checked using agarose gels. The DNA pieces were then inserted into pGEM T-Easy vector that included an ampicillin resistant gene and a LacZ reporter gene. The vectors were transformed into E. Coli and colonies that exhibited a white color, indicating these colonies contained the vector. The colonies were picked using a Q-pix picking robot. 384-well plates containing enriched broth were inoculated with the good colonies. DNA was isolated from these pine clones. The next steps will be to sequence the clones and analyze the sequence for genes. The program was supported by Mississippi Functional Genome Network

DIAGNOSIS, TREATMENT AND PREVENTION OF DISEASE ON FIRST YEAR BLACKBERRY, RUBUS SPP

Edward Heard* and Frank B. Matta, Mississippi State University, Mississippi State, MS 39762

The purpose is to provide local growers with effective methods of disease management for establishment of blackberry crops. Objectives include identification of disease causing organisms, management recommended by Mississippi Extension Service, and preventative methods to reduce incidence of common diseases. The blackberry research plot is located on MAFES North Farm, at Mississippi State. Symptoms and sign of foliar and floral pathogens were identified using a microscope and a moisture chamber at Mississippi State Plant Pathology Lab. Diseases detected are as follows: inter-veinal leaf blotch, Mycosphaerella confusa; floral gray mold and dieback, Alternaria sp.; and crown gall, Agrobacterium tumefaciens. Treatment thresholds were based on stand reduction. Alternated fungicide applications of pyraclostrobin + boscalid (FRAC group 11+7), captan (multi-site) and azoxystrobin (group 11) in late summer and early autumn managed foliar and floral diseases occurring after heavy rains. Preventative pre-plant root dip in Agrobacterium radiobacter suspension is recommended to manage crown gall. Suppressive soil disease Phytophthora root rot is prevented by minimal irrigation, allowing soil to dry frequently. Limited use of phosphorus fertilizer decreases late season flowers that allow an entry point for pathogens into the plant. Integrated disease management provides effective methods for blackberry crop establishment in Mississippi.

INFLUENCE OF CHELATES ON THE SOLUBILITY AND BIOACCUMULATION OF LEAD BY COFFEEWEED (SESBANIA EXALTATA RAF.)

Gloria S. Miller*, Maria F. Begonia, Gregorio B. Begonia, Diahanna Hackett, Jennifer Wallace, and Crystal Tyson, Jackson State University, Jackson, MS 39217

Phytoextraction is gaining popularity as a cost-effective and environmentally benign phytoremediation strategy for reducing toxic metal levels from contaminated soils. This study was conducted to further evaluate the suitability of Sesbania exaltata as one of the potential crop rotation species for phytoextraction. Specifically, the objective of this experiment was to determine whether the addition of ethylenediaminetetraacetic acid (EDTA) alone or in combination with acetic acid can further enhance the bioaccumulation of lead (Pb). Seeds were planted in plastic tubes containing top soil and peat (2:1, v:v) spiked with various levels (0, 1000, 2000 mg Pb/kg dry soil) of lead nitrate. At seven weeks after emergence, aqueous solutions of EDTA and acetic acid were applied to the root zone, and plants were harvested at 0, 5, and 7 days after chelate addition. Results revealed that coffeeweed was relatively tolerant to moderate levels of Pb as shown by non-significant differences in root and shoot biomass among treatments. Root Pb concentration increased with increasing level of soil-applied Pb. Further increases in root Pb were attributed to chelate amendments. Translocation index, which is a measure of the partitioning of the metal to the shoots, was significantly enhanced with chelate addition especially when both EDTA and acetic acid were used. Maximum translocation index occurred at 5 days after chelate addition. This observation coincided with the time when maximum amounts of Pb were bioavailable in the soil solution as shown in a corollary chelate-induced metal solubility study.

FRIDAY AFTERNOON

Exhibit Hall B

1:15 PESTICIDE RUNOFF FROM WARM-SEASON TURFGRASS SYSTEMS

Peter Ampim (1), Joseph H. Massey (1*), Barry Stewart (1), Cade Smith (1), Alton Johnson (2), Ashley Andrews (1), Kevin Armbrust (1), Rick Maiers (1), and Joni Cooks (1), (1) Mississippi State University, Mississippi State, MS 39762 and (2) Alcorn State University, Lorman, MS 39096

Anticipated rising pesticide use associated with increasing turf area across the nation may impair water quality in urban areas. Improving the accuracy of computer models currently used to predict turf pesticide runoff may enhance urban water systems protection. This study is part of a larger national research effort designed to improve the understanding and modeling of turf pesticide runoff. The specific objectives of the project are to investigate the effects of warm-season turfgrass species, mowing height and plot size on pesticide runoff. The turfgrass species include bermudagrass (Cynodon dactylon [L] Pers. x Cynodon transvalensis Burtt-Davy) and zoygrass (Zoysia japonica Steud.). The turfgrass species were maintained as either golf course fairways or residential lawns. The runoff plots were arranged in a split-plot design and were sloped at 3% with minimal cross slope. Following a standardized field protocol, 2, 4-D herbicide, flutolanil fungicide, and chlorpyrifos insecticide were co-applied at 1.12 kg ai/ha, 2.24 kg ai/ha and 2.24 kg ai/ha, respectively. A conservative tracer, KBr, was also applied at 10 kg/ha immediately before initiation of simulated rainfall. Simulated rainfall was applied to the plots at a rate of 38.1 mm/h for 90 min., 24 h after pesticide application. Runoff water from the plots was collected at approximately five-minute intervals. Collected runoff water and application monitor samples were analyzed by reverse phase High Performance Liquid Chromatography (HPLC) using UV-Vis detection. Maximum observed concentrations (ppb), total masses (g), and percentages of the applied chemicals observed in runoff water will be presented.

1:30 PHARMACEUTICAL SORPTION BY CORAL MUCUS AS A BIO-INDICATOR OF WASTEWATER CONTAMINATION

Ashley Andrews*, Joseph H. Massey, Kevin Armbrust, and Cade Smith, Mississippi State University, Mississippi State, MS 39762

In many coastal regions of the world, surface waters are being overloaded with nutrients. There is much controversy between different groups regarding the origin of these nutrients as with the hypoxia zone in the Gulf of Mexico. Researchers have found that coral mucus contains proteins and carbohydrates and is exuded at a rate of ~ 1.7 L/ m2 per day. Because of its physicochemical properties, coral mucus may sorbed organic contaminants found only in wastewater effluents. This project will analyze coral mucus for human-related drugs previously detected in wastewater. Analytical methods for drugs such as selective serotonin reuptake inhibitors (SRRIs) will be developed for coral mucus collected off the coast of Florida. If this proves successful, coral mucus has the potential of being used as a biomarker for wastewater effluent.

1:45 BLUEBERRY BIOMASS AND FRUIT QUALITY, AND GROUND WATER QUALITY IN A HEAVY SOIL AS AFFECTED BY ANIMAL AND FOREST WASTE

Girish K. Panicker (1*), Ahmad H. Al-Humadi (1), Cedric A. Sims (1), James Spiers (2), Juan L. Silva (3), and Frank B. Matta (3), (1) Alcorn State University, Alcorn State, MS 39096, (2) USDA Small Fruit Research Station, Poplarville, MS 39470, and (3) Mississippi State University, Mississippi State, MS 39762

Consumers are more concerned with health issues than ever before and numerous medical studies point to horticultural crops as a critical factor of healthy diet. While a lot of research and extension activities have been carried out on sustainable production systems in agronomic crops, there have been very few studies on horticultural crops. Rabbiteye blueberry (Vaccinium ashei Reade var. Tifblue) was grown on Memphis Silt Loam soil (Typic Hapludalph, silty, mixed, thermic). Two treatments of organic manures (worm castings--W, cow manure--C) were applied in basins around each plant. Control treatment received regular inorganic fertilizer. All treatments received pine bark and pine needle uniformly. No chemicals were applied to control pests, diseases and weeds. Leaf area index (LAI), percent canopy cover, canopy width and height, stem diameter, and yield were significantly higher in organic plants treated with worm castings. There was no significant difference in size, diameter, and degree brix of the fruit. No pathogenic organism from organic manures was found in fruits. Concentrations of nitrate-N and P were higher in the surface soil with organic manures, but there was no trend in N or P enrichment in lower layers of the soil. The leaching of N and P into subsurface layers from inorganic fertilizer was highly significant. The results show that blueberry can be grown successfully on heavy soils with forest waste that can increase soil acidity and worm castings are excellent organic manure for this crop.

2:00 ANALYSIS AT THE MICROSCOPIC LEVEL OF FUNGAL SPORE INOCULA APPLIED TO STRAWBERRY LEAVES FOR FUNGICIDE SCREENING EXPERIMENTS

Maritza Abril (1*), Kenneth J. Curry (1), and Barbara J. Smith (2), (1) University of Southern Mississippi, Hattiesburg, MS 39406 and (2) USDA-ARS, Small Fruit Research Station, Poplarville, MS 39470

The artificial inoculation of plants with fungal spores to test fungicide resistance is almost always reported with an inoculum concentration and general mechanism of application. A measure of the inoculum which actually arrives on the test plant is rarely assessed or reported. This opens the possibility of evaluating a fungicide as successfully protective when in fact the level of inoculum actually on the plant was insufficient for macroscopic manifestation of disease. The usual safeguard against this type of misinterpretation is the evaluation of an appropriate control. We have explored qualitatively and quantitatively at the microscopic level the disposition of fungal spore inocula (Colletotrichum acutatum) applied to strawberry leaves. Spraying both surfaces of an experimental leaf to the point of run off with various concentrations of spore inocula invariably leads to a lower concentration of spores than predicted on the adaxial surface of the leaf, and the abaxial surface of the leaf retains almost no spores! Thus the inoculum is considerably less than the experimenter believed it to be. A careful consideration of accuracy and precision in preparing spore inocula and various sources of error inherent in the inoculation process should prove beneficial to anyone undertaking fungicide screening experiments.

2:15 COLLECTING ISOLATES OF PHYTOPHTHORA CINNAMOMI FOR SCREENING BLUEBERRY CULTIVARS RESISTANT TO PHYTOPHTHORA ROOT ROT DISEASE

Melinda Miller-Butler (1*), Ann Curry (1), Kenneth J. Curry (1), and Barbara J. Smith (2), (1) University of Southern Mississippi, Hattiesburg, MS 39406 and (2) USDA-ARS Small Fruit Research Station, Poplarville, MS 39470

Phytophthora cinnamomi causes a severe root rot on many woody plant species including blueberry. We have isolated strains of Phytophthora cinnamomi from rabbiteye blueberry (Vaccinium ashei) cv. 'Tifblue' to use to identify phenotypes of this root rot fungus that express different levels of pathogenicity. (Milholland [1975] reported that V. ashei. cultivars are generally more resistant than V. corymbosum cultivars.) Infected blueberry roots and soil from an infested field were placed on Phytophthora selective culture media containing appropriate antibiotics to inhibit fungi and bacteria. Isolations were also attempted from (1) plant bait traps using root and soil with pieces of leaf tissue from susceptible plants: blueberry, avocado, and rhododendron floated in water, and from (2) roots embedded in apple or pear fruit. Our ultimate goal is use the collected Phytophthora phenotypes to develop plant tissue culture and greenhouse screening techniques to identify blueberry germplasm resistant or at least tolerant to Phytophthora root rot that will lead to root rot resistant cultivars which offer a means of controlling this disease in commercial blueberry fields.

2:30 Break

2:45 INFLUENCE OF ZINC COATING PLUG TRAYS ON THE PERFORMANCE OF MARIGOLD TAGETES PATULA, ZINNIA ZINNIA SP AND VINCA CATHARANTHUS ROSEUS

Pam Reid*, Frank B. Matta, and David H. Tatum, Mississippi State University, Mississippi State, MS 39762

The objective of this research was to investigate how zinc chloride influenced growth, levels of IAA, and root cell division of three bedding plant species. Plug trays used for growing Marigold Tagetes patula, Zinnia Zinnia sp and Vinca Catharanthus roseus were treated with Zinc Chloride at 0, 7, 14, 21, and 28 percent using white latex paint as the source of zinc. The plants were grown in a greenhouse at 85[degrees] F/65[degrees] F (day/night temperature) for 12 weeks. Plants were then harvested and plant and root fresh and dry weights were taken. To determine if indole-3-acetic-acid (IAA) was activated by zinc, trypthophan levels were measured. In addition, root cross-sections were examined microscopically to determine cell division. In this paper, vegetative growth (plant and root), trypthophan (IAA precursor), and the amount of root cell division as influenced by zinc chloride are reported.

3:00 INVESTIGATIONS INTO ITALIAN RYEGRASS (LOLIUM MULTIFORUM) RESISTANCE TO GLYPHOSATE 

James Blessitt (1*), Daniel H. Poston (1), Tom W. Eubank (1), and Clifford H. Koger (2), (1) Mississippi State University, Mississippi State, MS 39762, (2) CGPRU USDA-ARS, Stoneville, MS 39776

Glyphosate, most commonly sold under the trade name Roundup, is a non-selective herbicide that is widely used for weed removal prior to planting and also for postemergence weed control in glyphosate-tolerant crops. At several locations in the Mississippi delta in 2005, glyphosate did not control Italian ryegrass prior to planting. At all locations, glyphosate was applied at a commonly used rate that normally controls ryegrass and acceptable control was not achieved. Followup applications were made at all locations usually at a rate 2 times the normally applied dose. Control was still not achieved. Field and greenhouse studies were conducted to investigate the susceptibility of 3 Italian ryegrass populations to glyphosate. Seed were collected in the spring of 2005 from 2 field locations where glyphosate did not provide control. Seed were also collected from a 3rd location that had very little exposure to herbicides and was known to be susceptible to glyphosate. This population was used as a susceptible control. Glyphosate was applied at 0, 0.09, 0.19, 0.38, 0.75, 1.5, 3, and 6 lbs ae/acre. Plants grown from seed collected in fields where glyphosate did not control ryegrass appear to be approximately 3-fold more tolerant to glyphosate than known susceptible plants based on GR50 values derived from dose response curves.

3:15 INVESTIGATIONS ON THE USE OF STEROL INHIBITOR FUNGICIDES AS SEED TREATMENTS TO CONTROL SEEDLING DISEASES AND ASIAN SOYBEAN RUST

Bonnie C. Wells* and Gabe L. Sciumbato, MAFES/DREC, Stoneville, MS 38776

Soybeans are commonly treated with fungicides to control seedling diseases, such as those caused by Pythium sp. and Rhizoctonia solani. A new threat to the state's soybean crop is Asian soybean rust (ASR), which causes premature defoliation and can reduce yields by 80 percent. Sterol inhibiting fungicides (SI-fungicides) are effective in controlling ASR when applied at the initial stages of flowering. However, foliar fungicides are expensive and ASR may attack prior to flowering. Research was conducted to see if the SI-fungicides are phytotoxic to soybeans and determine their activity against seedling diseases and ASR. Fungicide treatments consisted of two standard seed treatments and eight SI-fungicides used for ASR control. Experimental design was a randomized complete block with four replications. Stand counts were recorded two and four weeks after planting. Yield data were collected. Results show no significant increases in seedling survival or yield for the standard seed treatments azoxystrobin and pyraclostrobin, indicating low disease pressure. All the SI-fungicides, except flutriafol and tebuconazole, significantly decreased seedling survival and yield. Propiconazole proved phytotoxic with an 89 percent average yield loss. No results were obtained for ASR seed treatment controls due to the absence of the disease. Research is in progress to evaluate different rates of flutriafol and tebuconazole to determine how long they are effective in controlling disease when used as a seed treatment.

3:30 SWEETPOTATO PRODUCTION AND UTILIZATION IN MISSISSIPPI

Falisha McDonald*, Patrick Igbokwe, Liang Huam, Juliet Huam, Franklin Chukwuma, Larry Russell, Arkon Burks, and Veronica Igbokwe, Alcorn State University, Alcorn State, MS 39096

Field studies were used in 2001 and 2002 growing seasons to investigate the effect of conventional (intensive-synthetic input) monocropping, transitional (reduced-synthetic input) and organic (non-synthetic input) multiple cropping systems on Beauregard sweetpotato (Ipomoea batatas) survival, yield, quality, and soil properties. Sweetpotato potential for becoming raw material for the development of value-added products was also investigated. These studies were conducted on a northern Mississippi Dexter silt loam soil. A randomized complete block (RCB) experiment design, with four replications of each cropping system (treatment) was used. Data analysis was by the analysis of variance, while means were separated by the Least significance difference (LSD) test. The effect of cropping systems on sweetpotato survival was significant in 2002. Root yield was significant for No.1 and No.2 sweetpotato grades in 2001, but only for No.1 in 2002. Root mineral compositions were significant for phosphorus, potassium, calcium, and magnesium 2001, whereas, root nitrogen, dry matter, protein, crude fiber, fat and ash contents were significant in 2002. In general, soil properties appeared to be improved after the second year of investigation. Taste test results suggest that the value-added products were different in appearance, flavor and texture.

3:45 Divisional Business Meeting