A HISTORY OF SOUTHERN REGIONAL PROJECTS ON SOILBORNE PLANT PATHOGENS, 1956-1999

Donald R. Sumner
University of Georgia, Tifton

The following is quoted from C. T. Wilson (7) "In November, 1953, The Southern Agricultural Experiment Station Directors approved a regional project in soil biology, with the understanding that the work would be activated in 1954-55, if additional funds were appropriated by Congress. C. T. Wilson was appointed Administrative Advisor and instructed to organize a technical committee and prepare a regional outline. The Technical Committee, consisting of C. E. Scarsbrook, Alabama; J. E. Giddens, Georgia; J. O. Andes and H. E. Reed, Tennessee; and E. T. York, North Carolina, met in January, 1954 to develop a project outline." There were three major interests of the committee: 1) biological transformation of N and decomposition of organic residues in soil, 2) developing an understanding of the soil microbiological aspects of plant diseases, and 3) studies on the factors affecting the soil microflora. The outline developed was rejected by the Southern Regional Research Committee because they felt that it was too broad and there were not enough scientists in the Southern Region to cover all areas outlined. Two more Technical Committee meetings were held in 1954 and 1955, and two different projects were approved: Southern Regional Project S-26 "The Relation of Soil Microorganisms to Soilborne Plant Pathogens" was established in 1956 and terminated June 30, 1972; and S-35 that was concerned with other areas of soil biology.

The first Technical Committee of S-26 was E. A. Curl, Alabama, J. H. Bond, South Carolina, and J. O. Andes and L. F. Johnson, Tennessee. The project had two objectives:

1. To determine the interrelationships of pathogenic and nonpathogenic soil microflora and the effect of these relationships on the incidence and severity of plant diseases.

2. To develop more effective means of using antagonistic reactions and associated biological phenomena among soil microorganisms to control plant diseases.

In 1967 the project was revised with two objectives:

1. Determine the behavior of soilborne plant pathogens as influenced by soil microorganisms, living plants, plant residues, and soil amendments.

2. Develop new and improved techniques for studying soil microbial communities.

The first Administrative Advisor was C. T. Wilson, Virginia, and he was replaced by P. H. Massey, Jr., Virginia, in 1966. Others who served on the technical committee at times were: N. D. Fulton, Arkansas; P. Decker, Florida; C. R. Jackson, Georgia; B. J. Bloomfield, L. Henson, W. D. Valleau, Kentucky; S. J. P. Chilton, Louisiana; W. Witcher, South Carolina; L. S. Bird, Texas; K. H. Garren, Virginia; W. A. Ayers, V. R. Boswell, C. B. Davey, E. B. Lambert, J. D. Menzies, G. C. Papavizas, ARS, USDA; J. M. Barnes, J. F. Fulkerson, E. L. LeClerg, W. D. McClelan, CSRS, USDA; W. A. Campbell, A. A. Foster, C. S. Hodges, E. G. Kuhlman, Forest Service, USDA.

During the organization of the project, the technical committee realized the need for a manual on on methods for research on soilborne pathogens and other microorganisms. In 1956 a book was published as a contribution of S-26 (6). An extensive revision of the book was published in 1972 (5). At the end of S-26 a Southern Cooperative Series Bulletin was published through the Research Division of VPI and State University (7).

The Southern Regional Research Committee recommended a new area of work, and a planning meeting was held in Atlanta in March, 1972 to discuss "Rhizosphere Ecology and Bioenvironmental Control of Plant Diseases". The S-26 Technical Committee had suggested that the following disciplines be included: plant pathology, microbiology, protozoology, plant physiology, biochemistry, plant breeding, toxicology, and soil science.

S-90 " Rhizosphere Ecology as Related to Plant Health and Vigor’ was approved in 1972 with the following objectives:

1. To determine quantitatively and qualitatively rhizosphere microorganisms and root exudates(including seed exudates), their roles in propagule response, fungistasis, and microbial interactions.

2. To determine interactions of root nutrient uptake and balance, root exudation, and rhizosphere microorganisms.

3. To refine essential techniques for studying root exudation, microbial interaction, root nutrient uptake, and develop other methodology for implementing objectives 1 and 2.

4. To analyze implementation potential of the results obtained to improve plant health and vigor while lessening any unfavorable impact of agricultural practices on the environment.

Because there was the potential of new federal funds, there were 30 scientists at the first meeting of the Technical Committee in 1972. However, new funds were not forthcoming, and participation in the project was less in later years. The first Administrative Advisor was R. J. McCracken, North Carolina Experiment Station. He was replaced by J. Lawrence Apple, North Carolina Experiment Station, in 1973. Technical Committee members were: E. A. Curl and R. Rodriguez-Kabana, Alabama; J. P. Jones, S. S. Woltz, R. A. Kinloch, D. H. Hubbell, N. C. Schenck, R. T. McMillan, D. J. Mitchell, and E. P. Ducharme, Florida; F. F. Hendrix, R. W. Roncadori, D. Phillips, G. A. Couvillon, J. Giddins, W. M. Powell, S. M. McCarter, D. R. Sumner, and F. A. Pokorny, Georgia; D. M. Huber, Indiana; C. E. Rieck, Kentucky; A. D. Larson, Louisiana; G. L. Barnes, Oklahoma; W. Witcher and C. L. Lane, South Carolina; L. F. Johnson, Tennessee; L. S. Bird, Texas; G. J. Griffin and M. G. Hale, Virginia; G. C. Papavizas, P. Dukes, K. H. Garren, P. H. Van Schaik , R. M. Sayre, G. Fassuliotis, D. M. Porter, W. A. Ayers, and R. D. Lumsden, ARS, USDA; and J. M. Barnes and J. F. Fulkerson, CSRS, USDA.

S-90 was revised January 1, 1978 and terminated December 31, 1982. The objectives in the revision were:

1. To advance basic knowledge and understanding of the quantitative and qualitative nature of root and seed exudates and of microbial components of the rhizosphere with special regard to the influence of cultivars, physical and chemical soil factors, nutrients and pesticides.

2. To determine interactions of rhizosphere components with plant resistance, with pathogen survival and proliferation, and with disease potential.

3. To further develop and refine essential techniques for studying root exudation, microbial interaction, and root nutrient uptake, and develop other methodology for implementing objectives 1 and 2.

4. To analyze the potential for implementation of research results to improve plant health and vigor while lessening any unfavorable impacts of agricultural practices on the environment.

J. L. Apple was replaced as Administrative Advisor by J. M. Davidson, Florida Experiment Station, in 1981. Technical Committee members were: E. A. Curl, R. Rodriguez-Kabana, P. A. Backman, and A. J. Latham, Alabama; J. P. Jones, N. C. Schenck, R. T. McMillan, and D. J. Mitchell, Florida; D. R. Sumner and G. A. Couvillon, Georgia; D. M. Huber, Indiana; J. W. Hendrix, Kentucky; D. M. Benson, North Carolina; G. L. Barnes, Oklahoma; C. L. Lane and H. D. Skipper, South Carolina; L. F. Johnson, Tennessee; L. S. Bird, Texas; G. J. Griffin and M. G. Hale, Virginia; A. J. Kappelman, Jr., C. M. Heald, A. W. Johnson, D. J. Weaver, E. J. Wehunt, J. H. Edwards, P. D. Dukes, K. H. Garren, R. M. Sayre, D. M. Porter, W. A. Ayers, and R. D. Lumsden, ARS, USDA. The CSRS representative was J. F. Fulkerson.

A new project, S-186 " Management of soil microorganisms affecting the health and vigor of plants" was approved from 1983 to 1989.

The objectives were:

1. To determine the influence, interactions, and distribution of soil microorganisms that suppress pathogens and promote plant health and vigor.

2. To evaluate the influence of chemical compounds, germplasm, and cultural practices on soil microorganisms affecting plant health and vigor.

3. To devise, modify, and evaluate techniques for determining the identity, interactions, and effects on plants of biological, chemical, and physical soil components.

4. To develop feasible management procedures for optimum plant health and protection of the environment.

The objectives were organized as Research Coordinating Units. Chairpersons for each RCU coordinated planning and reporting of the research in each unit.

The Administrative Advisor was J. M. Davidson, Florida Experiment Station. Technical Committee members were: E. A. Curl, Alabama; N. C. Schenck, Florida; D. R. Sumner, Georgia; D. M. Huber, Indiana; J. W. Hendrix and R. S. Ferriss, Kentucky; E. P. Dunigan, R. W. Schneider, and J. W. Hoy, Louisiana; W. J. Manning, Massachusetts, W. E. Batson, Mississippi; J. L. Peterson and R. F. Myers, New Jersey; D. M. Benson and A. G. Wollum, North Carolina; L. L. Singleton, Oklahoma; L. F. Johnson, Tennessee; L. S. Bird, K. M. El-Zik, C. M. Kenerley, and C. M. Rush, Texas; G. J. Griffin and P. M. Phipps, Virginia; D. M. Porter, W. A. Ayers, D. Fravel, and R. D. Lumsden, ARS, USDA. The CSRS representative was J. F. Fulkerson.

A new project, S-241 " Management of rhizosphere dynamics to control soilborne pathogens and promote plant productivity" was approved from 1990 to 1995.

The objectives were:

1. To determine the critical biotic and abiotic factors necessary for the establishment and enhancement of biocontrol agents and other organisms in soil and in the rhizosphere of plants.

2. To determine the components of genetic diversity of soilborne microorganisms that will facilitate the development of transformation systems, classification systems and assays for monitoring these populations.

3. To determine the effects of edaphic and biological factors and chemicals , germplasm and cultural management factors on soilborne plant pathogens and plant productivity..

The objectives were organized as Research Coordinating Units. Chairpersons for each RCU coordinated planning and reporting of the research in each unit. Regional seed treatment experiments with cotton, soybean, and snapbean were conducted, and regional tillage and cropping systems experiments were coordinated. Results of the regional experiments were summarized each year in the annual report.

The first Administrative Advisor, J. M. Davidson, Florida Experiment Station, was replaced in 1991 by E. R. Emino, Florida Experiment Station. Technical Committee members were: E. A. Curl, Alabama; C. S. Rothrock, Arkansas; N. C. Schenck and F. N. Martin, Florida; D. R. Sumner, Georgia; D. M. Huber, Indiana; J. W. Hendrix and R. S. Ferriss, Kentucky; R. W. Schneider, and J. W. Hoy, Louisiana; W. J. Manning, Massachusetts, W. E. Batson, Mississippi; J. L. Peterson, New Jersey; D. M. Benson and J. B. Ristaino, North Carolina; L. L. Singleton, K. E. Conway, and C. C. Russell, Oklahoma; L. F. Johnson and M. F. Windham, Tennessee; K. M. El-Zik, C. M. Kenerley, and P. M. Thaxton, Texas; P. M. Phipps, Virginia; D. M. Porter and D. Fravel, ARS, USDA.

A new project, S-269 " Biological control and management of soilborne plant pathogens for sustainable crop production" was approved from 1995 to 2000.

The objectives were:

1. Selection and optimization of biological control agents, and evaluation of seed treatment and other application techniques, to enhance biological control of diseases caused by soilborne plant pathogens.

2. Determination of the applicability and efficacy of biological control agents across different pathogens, crop species, and cultivars to select biological control agents for more effective disease control..

3. Implementation of management strategies including crop sequences , tillage, and other cultural practices to promote biological control with indigenous organisms.

The objectives were organized as Research Coordinating Units. Chairpersons for each RCU coordinated planning and reporting of the research in each unit. Under RCU I, regional evaluations on selected biocontrol agents were done on direct-seeded cotton, wheat, and snap bean. Under RCU III, regional tests were done on different management and cultural practices on different soil types.

The Administrative Advisor was E. R. Emino, Florida Experiment Station. Those who served on the Technical Committee at times were: D. J. Collins, P. A. Backman, and J. Kloepper, Alabama; C. S. Rothrock, Arkansas; M. L. Elliott and L. E. Datnoff, Florida; D. R. Sumner, Georgia; D. M. Huber, Indiana; J. W. Hendrix, Kentucky; R. W. Schneider, and J. W. Hoy, Louisiana; W. E. Batson, Mississippi; D. M. Benson, North Carolina; L. L. Singleton, and K. E. Conway, Oklahoma; A. P. Keinath, South Carolina; B. H. Ownley, Tennessee; K. M. El-Zik, and P. M. Thaxton, Texas; and C. M. Howell, ARS, USDA.

Participants in RCU I submitted a Southern Regional IPM grant proposal "Evaluation of biological seed treatments to control seedling diseases of cotton and snapbean", and a grant was approved for $104,892 to support the regional research from 1997-1999. Results of the regional seed treatment tests were published in Biological & Cultural Tests published by the American Phytopathological Society (1-4).

Literature Cited

1. Batson, W. E., Jr., J. Caceres, P. Backman, M. Benson, P. M. Brannen, M. A. Cubeta, M. L. Elliott, D. M. Huber, A. P. Keinath, B. Ownley, C. S. Rothrock, R. W. Schneider, C. E. Molsenbocker, D. R. Sumner, and P. Thaxton. 1998. Efficacy of biological seed treatments for control of the cotton seedling disease complex, 1997. Biological and Cultural Tests 13:21-22.

2. Batson, W. E., Jr., J. Caceres, P. Backman, M. Benson, P. M. Brannen, M. A. Cubeta, M. L. Elliott, D. M. Huber, A. P. Keinath, C. S. Rothrock, R. W. Schneider, C. E. Molsenbocker, and D. R. Sumner. 1998. Efficacy of biological seed treatments for control of seedling diseases of snap bean, 1997. Biological and Cultural Tests 13:145-146.

3. Batson, W. E., Jr., J. Caceres, M. Benson, P. M. Brannen, C. Canaday, K. Conway, M. A. Cubeta, M. L. Elliott, J. Fajardo, D. M. Huber, A. P. Keinath, B. Ownley, C. S. Rothrock, and D. R. Sumner. 1998. Biological seed treatments for control of seedling diseases of snap bean, 1998. Biological and Cultural Tests 14:149-150.

4. Batson, W. E., Jr., J. Caceres, M. Benson, P. M. Brannen, M. A. Cubeta, K. Conway, M. L. Elliott, J. Fajardo, D. M. Huber, A. P. Keinath, M. Newman, B. Ownley, C. S. Rothrock, R. W. Schneider, C. E. Molsenbocker, D. R. Sumner, and P. Thaxton. 1999. Biological seed treatments for control of the seedling disease complex of cotton 1998. Biological and Cultural Tests 14:25-26.

5. Johnson, L. F., and E. A. Curl. 1972. Methods for research on the ecology of soil-borne plant pathogens. Burgess Publishing Co., Minneapolis, MN. 178 p.

6. Johnson, L. F., E. A. Curl, J. H. Bond, and H. A. Fribourg. 1959. Methods for studying soil microflora-plant disease relationships. Burgess Publishing Co., Minneapolis, MN. 178 p.

7. Papavizas, G. C., ed. 1974. The relation of soil microorganisms to soilborne plant pathogens, a summary of contributions to the Southern Regional Project S-26. Southern Cooperative Series Bulletin 183, VPI and State Univ., Blacksburg. 98 p.