First Report of Meloidogyne partityla on Pecan in Florida.

Pecan (Carya illinoensis (Wagenh.) K. Koch) is an important tree in the southern United States for commercial nut production and residential use. Meloidogyne partityla (pecan root-knot nematode) is only known to parasitize trees in the Juglandaceae including pecan, walnut, and hickory. In the United States, it has been reported on pecan in Texas, New Mexico, and Georgia and internationally in South Africa. Portions of a large pecan nursery in Madison County, Florida were infested with an unknown species of root-knot nematode. The pecan trees at this nursery are grafted onto rootstock and grown in the field until the trees are large enough to sell as bare-root transplant stock in several states including and adjoining Florida. Trees infected by the root-knot nematodes were stunted, had extensive galling and rotting of the root system, and pulled from the ground relatively easily compared with noninfected trees. Attempts to rear these nematodes on tomato in the greenhouse were unsuccessful. Young egg-laying females were isolated directly from pecan roots for speciation. Enzymes extracted from females were resolved with polyacrylamide gel electrophoresis [4% stacking (pH 6.8) and 8% separating gel (pH 8.8) with Tris-glycine buffer]. The esterase (Est) and malate dehydrogenase (Mdh) phenotypes of the unknown Meloidogyne sp. were consistent with those reported for M. partityla. In addition, specimens of M. partityla maintained by the USDA Southeastern Fruit and Tree Nut Research Laboratory in Byron, GA were obtained and their Est and Mdh phenotypes compared with the unknown Meloidogyne sp. under identical electrophoretic and enzyme staining protocols. The Est and Mdh phenotypes of the two isolates were identical. Therefore, we conclude that the root-knot nematodes infesting the pecan nursery in Florida are M. partityla. To our knowledge, this is the first report of this nematode in Florida and also the first report of this nematode from infected nursery stock. It is unknown how long the field has been infested but clearly, there is potential for spread of M. partityla to locations around Florida and bordering states. This nematode may be widespread throughout pecan-growing regions of the United States. References: (1) K. P. N. Kleynhans. Phytophylactica 18:103, 1986. (2) A. P. Nyczepir et al. Plant Dis. 86:441, 2002. (3) J. L. Starr et al. J. Nematol. 28:565, 1996. (4) S. H. Thomas et al. Plant Dis. 85:1030, 2001.

Synthesis of an L-quinovose-containing disaccharide.

The synthesis of a versatile L-rhamnose monosaccharide synthon is described. This synthon is used in the synthesis of a disaccharide containing the rare sugar, 6-deoxy-L-glucose, linked to the 3-C-hydroxymethyl group of methyl 2,3-O-isopropylidene 3-C-(hydroxymethyl)-beta-D-erythrofuranoside.

Management of Root-knot and Reniform Nematodes in Ultra-Narrow Row Cotton with 1,3-Dichloropropene.

Ultra-narrow row cotton studies were conducted during 1999 at two field sites in northern Florida. One site was naturally infested with Meloidogyne incognita Race 3 and the other with Rotylenchulus reniformis. The fumigant 1,3-dichloropropene (1,3-D) was applied broadcast at rates of 0, 16, 32, 48, 64, 80, and 96 kg ai./ha in replicated plots before planting Delta Pine 655 BRR cotton in 25-cm-wide rows. Post-harvest soil population densities at the root-knot nematode site had a significant (P

First Report of Tomato spotted wilt virus in Habanero and Tabasco Peppers in Florida.

In spring 2000, symptoms similar to thrips-vectored spotted wilt disease caused by Tomato spotted wilt virus (TSWV) were observed on habanero (Capsicum chinense) and tabasco (Capsicum frutescens) peppers in north Florida. Habanero peppers were from commercial fields grown for specialty markets and tabasco peppers were from research plots. Symptoms observed were leaf necrosis, fruit drop, necrotic stem lesions, and stunting. Fruit symptoms included chlorotic and necrotic spotting and distinct ring pattern and distortion. The incidence of symptomatic habanero peppers was 7 to 8% in one of the three production fields visited, and a lower incidence in two other fields (all in Jackson County). In tabasco pepper, TSWV was detected in spring and fall 1999, and spring 2000 seasons in 10 to 15% of the plants (Gadsden County). Adjacent tomato fields contained scattered plants exhibiting symptoms of TSWV. Diagnosis of TSWV from symptomatic stems, leaves, and fruit of habanero and tabasco peppers was confirmed by a double antibody sandwich enzyme linked immunosorbent assay (ELISA) using a commercially available kit (Agdia Inc., Elkhart, IN). ELISA values ranged from 1.57 to 1.95 for habanero pepper and 0.80 to 0.95 for tabasco pepper. The mean ELISA value of the negative controls was 0.001. To further verify TSWV infection, immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) was performed (1). The primer pair 5'-ATGTCTAAGGTTAAGCTC-3' and 5'-TTAAGCAAGTTCTGTGAG-3' represented the first and last 18 bases of the coding region of the nucleocapsid gene of TSWV, respectively, and produces approximately 800 bp PCR product (1). IC-RT-PCR gave a single DNA band of expected size in both habanero and tabasco samples, while no amplification was found in an uninfected pepper sample. This is the first report of TSWV on habanero and tabasco peppers in Florida. TSWV continues to be an economically important disease constraint to the production of tomato, pepper (C. annuum), peanut, and tobacco in the southeastern United States (observations from Georgia and Florida). Meanwhile, the known host range is expanding to include new species of cultivated vegetables. References: (1) R. K. Jain et al.. Plant Dis. 82:900, 1998.

Utility of Mi Gene Resistance in Tomato to Manage Meloidogyne javanica in North Florida.

Three field trials were conducted to determine response of Meloidogyne javanica to tomato cultivars containing the Mi gene for resistance in sequential tests. Trials were conducted in spring and fall 1997 and spring 1998 on the same site. Tomatoes were grown on polyethylene mulch at a site initially treated with methyl bromide and then infested with M. javanica via drip tubing. Cultivars with the Mi gene were 'PSR 8991994' and 'Sanibel', and susceptible cultivars were 'Colonial' and 'Agriset 761'. The resistant cultivars greatly suppressed root galling in the three tests. Population densities of second-stage juveniles also were low in soil samples collected from resistant cultivars. Tomato fruit yields were significantly increased in only one test when using resistant cultivars. However, the susceptible cultivars are high-yielding and recommended for north Florida production, while the cultivars containing the Mi gene are not as well adapted. In the three successive crops, no evidence of resistance-breaking biotypes of M. javanica was observed. With further incorporation into adapted cultivars, the Mi gene resistance could be a valuable tool to manage M. javanica in north Florida stake tomato production.

Surgical outcomes in pure frontal lobe epilepsy and foci that mimic them.

In this study we examined 37 subjects with a diagnosis of intractable frontal lobe epilepsy (FLE) based on non-invasive pre-surgical evaluation. Twenty-six underwent chronic intracranial ictal recordings (CIR) with video monitoring; 20 of these went on to surgical resection. Eleven underwent surgery without CIR. Retrospectively, we determined that 19 had pure FLE, 12 had frontal plus extrafrontal epileptogenic zones, and six others did not have FLE. We analysed the whole group and individual categories to evaluate the determinants of surgical outcome. Sixty percent of the pure frontal group is seizure free with all having > or = 75% reduction. The frontal-plus group had only 10% seizure free with 70% having > or = 75% reduction. Being in the pure frontal group was associated with better outcomes than the 'frontal-plus' group (P < 0.05; chi-square). Subjects with FSIQ > or = 85, focal pathologies and 18FDG-PET scans which were normal or had focal abnormalities (P < or = 0.05, all, chi-square) were more likely to have excellent outcomes. MRI abnormalities, surface EEG, and location and size of resection were not predictive of surgical outcomes. Rasmussen's encephalitis, incomplete surgical strategies and bilateral foci were apparent in those with poor outcomes, and surgical size predicted post-operative deficits (chi-square; P < 0.001). We conclude that careful, hypothesis-driven implants and operating procedures can result in good surgical outcomes for frontal lobe epilepsy subjects even when lesions are not apparent on routine neuroimaging.

Responses of Cotton Yield and Meloidogyne incognita Soil Populations to Soil Applications of Aldicarb and 1,3-D in Florida.

In four tests conducted in loamy-sand soils in northern Florida, cotton lint yield increased and post-harvest soil populations of Meloidogyne incognita were more effectively suppressed by 1,3-dichloropropene (1,3-D) than aldicarb when both nematicides were evaluated over a range of recommended rates. Significant positive relationships existed between lint yield and rates of 1,3-D in three tests, whereas only one significant positive relationship occurred between lint yield and aldicarb rates. Yield increases ranged from 16% to 124%, depending on rate of 1,3-D, and 35% in one aldicarb-treated test. Only a weak negative relationship between post-harvest soil densities of second-stage juveniles (J2) and aldicarb rates was determined by combining data from the four tests. Aldicarb failed to suppress post-harvest J2 soil population densities in any test. All rates of 1,3-D significantly reduced post-harvest M. incognita J2 soil population densities in two tests and provided a stronger negative correlation between nematode soil densities and rates than aldicarb when all test data were combined for each nematicide.

The safety and efficacy of chronically implanted subdural electrodes: a prospective study.

BACKGROUND: The popularity of subdural electrodes for the presurgical evaluation of patients with intractable seizures is increasing. However, few reports have prospectively dealt with their efficacy and safety. METHODS: We conducted a 5-year prospective study of patients evaluated by the California Comprehensive Epilepsy Program, who subsequently underwent subdural electrode implantation at one of two institutions. Efficacy was examined by ultimate outcome with regards to postsurgery resection seizure frequency. Fifty-five patients underwent 58 implant procedures and postresection outcomes were available in 47 patients. Safety was defined by the incidence of expected and unexpected complications, and neuropathologic examination of tissue specimens. RESULTS: The most common expected adverse effects during implant were fever < or = 102 degrees (41%), cerebrospinal fluid leakage (19%), headache (15%), and nausea (4%). There were no infections. Unexpected adverse events included fever > 102 degrees F (5%), migraine (5%), iatrogenic electrode dysfunction (5%), and temporalis muscle fibrosis (5%). The incidence of pathologic findings suggestive of foreign body reaction was 10%. There were no permanent sequelae. Surgical outcomes were excellent in all (> or = 75% seizure reduction) with 50% seizure free regardless of the focus. CONCLUSIONS: Subdural electrodes are a safe, easy, and efficacious tool for evaluating seizure foci prior to resective surgery. They should no longer be considered investigational devices.

Evaluation of Fosthiazate for Management of Meloidogyne javanica in Florida Flue-cured Tobacco.

One grower trial and two experiment station tests were conducted to evaluate a new nematicide, fosthiazate, for management of Meloidogyne javanica in Florida flue-cured tobacco. Fosthiazate was applied broadcast and incorporated at rates ranging from 21 to 84 g/100 m(2) and compared with 1,3-dichloropropene at 240 and 460 ml/100 m(2) and fenamiphos at 67 g/100 m(2). All fosthiazate treatments increased tobacco yields and reduced root galling. Application of 1,3-D provided the highest tobacco yields and greatest reductions in root galling. The fenamiphos treatment outperformed all fosthiazate treatments in tobacco yield and root gall reduction. Fosthiazate may therefore have limited utility compared with 1,3-D and fenamiphos as a nematicide for tobacco in peninsular Florida.

Ethoprop depletion from soil as influenced by simulated rainfall.

Two field microplot tests were conducted in sandy soil to evaluate retention of ethoprop in relation to simulated rainfall levels. Ethoprop was applied at the equivalent of 13.5 kg a.i./ha, and simulated rainfall was added at rates of 2.5, 7.5, 15.0, and 22.5 cm over a 6-day period. Ethoprop concentration in the soil at 5-, 10-, and 40-day intervals indicated that it was depleted rapidly with increased rainfall levels. The 2.5-cm level of simulated rainfall reduced ethoprop concentration to one-half in the 0 to 15 cm depth within 10.7 days, whereas the 22.5 cm of rain shortened this period to 1.7 days. Soil samples taken 10 days after ethoprop treatment and inoculated with Meloidogyne javanica indicated that 2.5 cm of rain rendered the nematicide ineffective against M. javanica.

Altered patterns of dynorphin immunoreactivity suggest mossy fiber reorganization in human hippocampal epilepsy.

Dynorphin A(1-17), an opioid peptide that is normally present in the hippocampal mossy fiber system, was localized immunocytochemically in the hippocampal formation of control autopsy and temporal lobe epilepsy (TLE) specimens. In control tissue, dynorphin-like immunoreactive (Dyn-IR) structures were confined to the mossy fiber path and were most highly concentrated in the polymorph (hilar) region of the dentate gyrus. Very few Dyn-IR structures were present in the molecular and granule cell layers of the dentate gyrus. In contrast, in all TLE specimens, Dyn-IR elements were present in these layers. The extent of aberrant staining varied among the TLE specimens, and 2 major patterns were observed. The first was a relatively wide band of reaction product in the inner one-third to one-fourth of the molecular layer (8 cases), and the second was a more limited distribution of immunoreactive fibers and presumptive terminals in the granule cell and immediately adjacent supragranular regions (2 cases). The extent of aberrant Dyn-IR structures appeared to be related to the amount of cell loss in the polymorph and CA3 fields and to dispersion of the granule cell somata. Specimens processed with the Timm's sulfide silver method for heavy metals provided independent evidence for the distribution of mossy fibers. In both control and TLE specimens, the patterns of labeling were virtually identical to those of dynorphin localization. These findings suggest that sprouting of mossy fibers or their axon collaterals has occurred in hippocampal epilepsy and that the reorganized fibers contain at least one of the neuropeptides that are normally present in this system. Such fibers could form recurrent excitatory circuits and contribute to synchronous firing and epileptiform activity, as suggested in studies of experimental models of epilepsy.

Chemical Control of Nematodes on Flue-cured Tobacco in Brazil, Canada, United States, and Zimbabwe.

A survey was conducted in four major flue-cured tobacco producing countries to determine use of nematicides for control of plant-parasitic nematodes on flue-cured tobacco. Included in the survey were scientists from Brazil, Canada, the United States, and Zimbabwe. Nematicides were used on 60-95% of the flue-cured tobacco crop in these regions. The choice of fumigant and nonfumigant nematicides, however, varied greatly as influenced by the edaphic factors, nematode species, and other pests present. The major nematicides, application methods, and efficacy evaluation systems used in these countries were addressed.

Effect of Meloidogyne incognita and M. javanica on Leaf Water Potential and Water Use of Tobacco.

Greenhouse lysimeter and field microplot tests were conducted to evaluate the effects of Meloidogyne incognita and M. javanica on plant water relations and growth performance of NC 2326 flue-cured tobacco. In the greenhouse, afternoon leaf water potential values at 8-11 weeks after transplanting were lower by as much as 0.22 MPa in plants infected with either nematode than in the control plants. From 11 to 22 weeks, leaf water potential values were similar in all treatments. Over the course of the 22-week experiment, all infected plants showed similar evapotranspiration patterns, and plants in these treatments used 87-88% of the water utilized by noninfected plants. Biomass production from nematode-infected plants, however, was only about 50% of the biomass of control plants. The field microplot study showed water use patterns similar to those in the lysimeter study.

Nicotine Content of Tobacco Roots and Toxicity to Meloidogyne incognita.

The motility of Meloidogyne incognita second-stage juveniles (J2) and their ability to induce root galls in tomato were progressively decreased upon exposure to nicotine at concentrations of 1-100 mug/ml. EC values ranged from 14.5 to 22.3 mug/ml, but J2 motility and root-gall induction were not eliminated at 100 mug/ml nicotine. Nicotine in both resistant NC 89 and susceptible NC 2326 tobacco roots was increased significantly 4 days after exposure to M. incognita. The increase was greater in resistant than in susceptible tobacco. Root nicotine concentrations were estimated to be 661.1-979.1 mug/g fresh weight. More M. incognita were detected in roots of susceptible than in roots of resistant tobacco. Numbers of nematodes within resistant roots decreased as duration of exposure to M. incognita was increased from 4 to 16 days. Concentrations of nicotine were apparently sufficient to affect M. incognita in both susceptible and resistant tobacco roots. Localization of nicotine at infection sites must be determined to ascertain its association with resistance.

Distribution of field corn roots and parasitic nematodes in subsoiled and nonsubsoiled soil.

A field trial was conducted for 2 years in an Arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. Soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. At 30 and 60 days, in-row nematode population densities to 60 cm deep were not affected by subsoiling compared with population densities in nonsubsoiled plots. After 90 days, subsoiling had not affected total root length or root weight at the 20 depth-row position sampling combinations, but population densities of Meloidogyne incognita and Criconemella spp. had increased in subsoiled corn. Numbers of Pratylenchus zeae were not affected. Subsoiling generally resulted in a change in distribution of corn roots and nematodes in the soil profile but caused little total increase in either roots or numbers of nematodes. Corn yield was increased by subsoiling.

Corn response to subsoiling and nematicide application.

A 2-year field study evaluated the influence of subsoiling and nematicide application, alone and in combination, on the growth and yield of field corn in a sandy soil in north-central Florida. The field had a 25-30-cm-deep tillage pan (plowpan) and was infested with Belonolaimus longicaudatus, Hoplolaimus galeatus, Trichodorus christei, and Pratylenchus spp. Subsoiling increased corn yield both years, and the residual effect of subsoiling in the first year increased yields in the second year. Preplant application of DD injected in-row increased yields and reduced nematode populations. At-planting applications of DD injected in-row and carbofuran in-furrow or in a band were less effective than subsoiling in increasing yields and reducing nematode numbers. Interactions between subsoiling and nematicide treatments occurred in the second year.

Population Development and Pathogenicity of Meloidogyne javanica on Flue-cured Tobacco as Influenced by Ethoprop and DD.

Growth of flue-cured tobacco as influenced by Meloidogyne javanica and the effectiveness of DD and ethoprop to manage this nematode were evaluated over two growing seasons. Populations of M. javanica, root galling, plant height, steam crown diameter, whole plant weight, and yield were monitored at approximately 2-week intervals beginning 28 days after transplanting. Treatment influence on nematode population development, root galling, and plant growth generally followed a pattern in descending order of efficacy: DD (187 liters/ha), ethoprop (27, 18, or 9 kg a.i./ha), and control. In all treatments, nearly season-long increases in M. javanica populations and root galling were observed. Correlation coefficients relating nematode populations or root galling to final tobacco yield suggested either method may be used successfully to evaluate nematicide efficacy in research plots. Plant growth parameters most affected by M. javanica in order of decreasing severity were cured leaf yield, whole plant weight, plant height, and stem diameter.