@article{sullivan_parks_cubeta_gallup_melton_moyer_shew_2010, title={An Assessment of the Genetic Diversity in a Field Population of Phytophthora nicotianae with a Changing Race Structure}, volume={94}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-94-4-0455}, abstractNote={ One hundred fifty-three isolates of Phytophthora nicotianae that were collected over a 4-year period from a single field were subjected to amplified fragment length polymorphism (AFLP) analysis to investigate the effect of different types of resistance in tobacco (Nicotiana tabacum) on genetic diversity in the pathogen population. No race 1 isolates were detected in the field prior to initiating the study, but the race was present in multiple plots by the end of the 4-year period. There were 102 race 0 isolates and 51 race 1 isolates characterized. Seventy-six of the 153 isolates had a unique AFLP profile, whereas the remaining 77 isolates were represented by 27 AFLP profiles shared by at least two isolates. Isolates of both races were found in both the unique and shared AFLP profile groups. Twenty-three of the AFLP profiles were detected in multiple years, indicating a clonal component to the pathogen population. Race 1 isolates that were detected over multiple years were always obtained from the same plot. No race 1 profile was found in more than one plot, confirming the hypothesis that the multiple occurrences of the race throughout the field were the result of independent events and not pathogen spread. Three identical race 0 AFLP profiles occurred in noncontiguous plots, and in each case, the plots contained the same partially resistant variety. Cluster analysis provided a high level of bootstrap support for 41 isolates in 19 clusters that grouped primarily by race and rotation treatment. Estimates of genetic diversity ranged from 0.365 to 0.831 and varied depending on tobacco cultivar planted and race. When averaged over all treatments, diversity in race 1 isolates was lower than in race 0 isolates at the end of each season. Deployment of single-gene resistance initially decreased genetic diversity of the population, but the diversity increased each year, indicating the pathogen was adapting to the host genotypes deployed in the field. }, number={4}, journal={PLANT DISEASE}, author={Sullivan, M. J. and Parks, E. J. and Cubeta, M. A. and Gallup, C. A. and Melton, T. A. and Moyer, J. W. and Shew, H. D.}, year={2010}, month={Apr}, pages={455–460} }
 @article{antonopoulos_melton_mila_2010, title={Effects of Chemical Control, Cultivar Resistance, and Structure of Cultivar Root System on Black Shank Incidence of Tobacco}, volume={94}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-94-5-0613}, abstractNote={ Black shank, caused by the hemibiotrophic oomycete Phytophthora parasitica var. nicotianae, is a major disease of tobacco (Nicotiana tabacum). The rise of race 1 in the late 1990s, after extensive cropping of cultivars possessing the Php gene, confirming immunity to race 0 of P. parasitica var. nicotianae, imposed new challenges to black shank management. The effects of tobacco cultivars and chemical controls with mefenoxam (Ridomil Gold) on black shank incidence were investigated in naturally infested fields. Twenty-five cultivars were tested and the highest resistance for races 0 and 1 of P. parasitica var. nicotianae was provided by RJR 75 and SP 227 based on field and laboratory studies. When race 1 was prevalent, mefenoxam was effective to control black shank. An initial application at an early stage of tobacco growth, such as a few days before or after transplant, was essential to successfully control the disease. In greenhouse experiments, cultivars carrying the Php gene produced fewer and shorter adventitious roots than cultivars possessing only partial resistance to all races of P. parasitica var. nicotianae. Strategies such as use of mefenoxam, especially at an early stage, when adventitious roots are emerging, and planting a cultivar with high partial resistance or possessing the Ph gene when race 1 or race 0, respectively, predominates are critical factors in reducing loss due to P. parasitica var. nicotianae. }, number={5}, journal={PLANT DISEASE}, author={Antonopoulos, Dimitrios F. and Melton, Thomas and Mila, Asimina L.}, year={2010}, month={May}, pages={613–620} }
 @article{sullivan_melton_shew_2005, title={Fitness of races 0 and 1 of Phytophthora parasitica var. nicotianae}, volume={89}, ISSN={["0191-2917"]}, DOI={10.1094/PD-89-1220}, abstractNote={ Deployment of tobacco (Nicotiana tabacum) varieties with complete resistance to race 0 of Phytophthora parasitica var. nicotianae has led to a rapid increase in the field populations of race 1 in North Carolina. In a field study, population levels of race 1 decreased relative to race 0 when cultivars with partial resistance to both races were planted, suggesting that race 1 isolates were less fit than race 0 isolates. Experiments were conducted to quantify differences in aggressiveness and survivability of the two races. Tobacco varieties with low, moderate, or high levels of partial resistance were inoculated with 60 pathogen isolates, and symptom development was monitored for 3 weeks. Race 0 isolates were more aggressive than race 1 isolates on cultivars with moderate or high levels of partial resistance; incubation periods were shorter and root rot severity was greater with race 0 isolates. Isolates of race 1, however, caused greater stunting of plants with moderate and high levels of partial resistance than race 0 isolates. Field microplots were infested with either a single race or an equal mixture of each race. Soil samples were collected at the end of two growing seasons and again the following spring. Pathogen populations declined from 40 to 80% during winter months, but population declines for race 0 were lower than for race 1 in each treatment over each winter. Race shifts from race 1 to race 0 that were observed in the presence of cultivars with partial resistance appear to be primarily the result of differences in aggressiveness of the races, with a possible minor effect of enhanced overwintering survival of race 0 compared with race 1. }, number={11}, journal={PLANT DISEASE}, author={Sullivan, MJ and Melton, TA and Shew, HD}, year={2005}, month={Nov}, pages={1220–1228} }
 @article{sullivan_melton_shew_2005, title={Managing the race structure of Phytophthora parasitica var. nicotianae with cultivar rotation}, volume={89}, ISSN={["0191-2917"]}, DOI={10.1094/PD-89-1285}, abstractNote={ Deployment of tobacco cultivars with single-gene, complete resistance to race 0 of the tobacco black shank pathogen, Phytophthora parasitica var. nicotianae, has resulted in a rapid increase in the occurrence of race 1 of the pathogen in North Carolina. Cultivar-rotation studies were conducted in three fields to assess how different levels and types of resistance affected the race structure and population dynamics of the pathogen when deployed in fields initially containing single or mixed races of the pathogen. In a field with both races present, a high level of partial resistance in cv. K 346 was most effective in reducing disease and decreasing the proportion of race 1 in the pathogen population. The deployment of complete resistance in cv. NC 71 resulted in intermediate levels of disease control and race 1 became the predominate race. The cv. K 326, with a low level of partial resistance, had the highest levels of disease, and race 0 was the dominant race recovered. In a field where no race 1 was detected initially, disease incidence was high with the use of partial resistance. Complete resistance was very effective in suppressing disease, but race 1 was recovered after only one growing season. By the end of the third growing season, race 1 was recovered from most treatments where single-gene resistance was deployed. A high level of partial resistance was most effective in suppressing disease in a field where race 1 initially was the predominant race. A rotation between cultivars with single-gene resistance and cultivars with a high level of partial resistance should provide the most effective approach to black shank management. This rotation will reduce disease incidence and minimize race shifts in the pathogen and, over time, should prolong the usefulness of the Ph gene for black shank control in commercial production of tobacco. }, number={12}, journal={PLANT DISEASE}, author={Sullivan, MJ and Melton, TA and Shew, HD}, year={2005}, month={Dec}, pages={1285–1294} }
 @article{ng'ambi_rufty_barker_melton_1999, title={Identification of sources of resistance to four species of root-knot nematodes in tobacco}, volume={31}, number={3}, journal={Journal of Nematology}, author={Ng'ambi, T. B. S. and Rufty, R. C. and Barker, K. R. and Melton, T. A.}, year={1999}, pages={272–282} }
 @article{leidy_sheets_melton_house_1998, title={Residues of iprodione and dimethomorph on flue-cured and burley tobaccos}, volume={42}, number={1998}, journal={Tobacco Science}, author={Leidy, R. B. and Sheets, T. J. and Melton, T. A. and House, J.}, year={1998}, pages={18–26} }
 @article{melton_wood_porter_1996, title={Evaluation of nematicides during the third year of use, 1995}, volume={51}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Wood, B. K. and Porter, D.}, year={1996}, pages={194} }
 @article{melton_wood_porter_1996, title={Nematicides during the third year of use for Southern root-knot on tobacco, 1995}, volume={51}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Wood, B. K. and Porter, D.}, year={1996}, pages={195} }
 @article{melton_wood_porter_1995, title={Evaluation of nematicides during the second year of use for southern root-knot, 1994}, volume={50}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Wood, K. and Porter, D.}, year={1995}, pages={208} }
 @article{melton_wood_porter_1995, title={Evaluation of nematicides during the second year of use, 1994}, volume={50}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Wood, K. and Porter, D.}, year={1995}, pages={209} }
 @article{melton_barker_koenning_powell_1995, title={Temporal efficacy of selected nematicides on Meloidogyne species on tobacco}, volume={27}, number={3}, journal={Journal of Nematology}, author={Melton, T. A. and Barker, K. R. and Koenning, S. R. and Powell, N. T.}, year={1995}, pages={263} }
 @article{melton_wood_porter_1994, title={Comparison of fosthiazate to commonly used nonfumigant and fumigant nematicides, 1993}, volume={49}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Wood, K. and Porter, D.}, year={1994}, pages={188} }
 @article{melton_porter_wood_1994, title={Evaluation of fungicide and nematicide combinations for the control of root knot and black shank, 1993}, volume={49}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Porter, D. and Wood, K.}, year={1994}, pages={190} }
 @article{melton_wood_porter_1994, title={Evaluation of nematicide combinations for the control of root-knot nematode, 1993}, volume={49}, journal={Fungicide and Nematicide Tests}, author={Melton, T. A. and Wood, K. and Porter, D.}, year={1994}, pages={189} }
 @article{melton_powell_1991, title={EFFECTS OF 2-YEAR CROP ROTATIONS AND CULTIVAR RESISTANCE ON BACTERIAL WILT IN FLUE-CURED TOBACCO}, volume={75}, ISSN={["0191-2917"]}, DOI={10.1094/PD-75-0695}, abstractNote={The incidence of bacterial wilt, caused by Pseudomonas solanacearum, was reduced and the yield of flue-cured tobacco (Nicotiana tabacum) was increased by cultivar resistance and by 1-yr rotation to corn, fescue, or soybeans as compared with continuous tobacco. In general, crop value and yield were highler and disease index lower when tobacco was grown after soybeans than after fescue, corn, or tobacco. The value, yield, and disease index for tobacco grown after corn and after fescue did not differ (...)}, number={7}, journal={PLANT DISEASE}, author={MELTON, TA and POWELL, NT}, year={1991}, month={Jul}, pages={695–698} }
 @article{melton_powell_1991, title={Effects of nematicides and cultivars on Rotylenchulus reniformis and flue-cured tobacco yield}, volume={23}, number={4}, journal={Journal of Nematology}, author={Melton, T. A. and Powell, N. T.}, year={1991}, pages={712} }
 @article{melton_phillips_imbriani_barker_1991, title={First report of Globodera tabacum solanacearum on flue-cured tobacco outside Virginia}, volume={75}, number={10}, journal={Plant Disease}, author={Melton, T. A. and Phillips, J. A. and Imbriani, J. L. and Barker, K. R.}, year={1991}, pages={1074} }