Source: PURDUE UNIVERSITY submitted to
ECOLOGY OF SOIL-BORNE PLANT PATHOGENS IN IMPORTANT INDIANA CROPS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0191690
Grant No.
(N/A)
Project No.
IND011275
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2006
Project End Date
Sep 30, 2011
Grant Year
(N/A)
Project Director
Westphal, A.
Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907
Performing Department
BOTANY AND PLANT PATHOLOGY
Non Technical Summary
Soil-borne fungi interact with plant-parasitic nematodes in the development of a soil-borne diseases. The occurrence and development of soil-borne diseases is impacted by biological and physical parameters. This project will investigate the interaction between soil-borne fungi and nematodes in development of soil-borne diseases. The nature of a soil-borne disorder of watermelon in Indiana will also be investigated. Studies of the interaction of soil-borne pathogens and beneficial organisms will improve the implementation of sustainable management options for soil-borne diseases.
Animal Health Component
25%
Research Effort Categories
Basic
50%
Applied
25%
Developmental
25%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121429110325%
2121820110220%
2151820112025%
2161820110215%
2161820112015%
Goals / Objectives
The objectives of this project are: 1. Determine the presence and distribution of soil suppressiveness against H. glycines in Indiana. 2. Determine potential association of SDS with soil physical and biological characteristics. 3. Study the interaction of soybean cyst nematode with SDS in disease severity and incidence. 4. Determine the damage potential and management of soil-borne diseases of watermelon in South Indiana.
Project Methods
1. Soil suppressiveness against Heterodera glycines One hundred soils were tested for suppressiveness based on previously developed tests (Westphal and Becker, 1999, 2001; Westphal, 2005). A number of suppressive soils were identified with low nematode reproduction compared to others. Microbes associated with cysts in these suppressive soils will be isolated. Promising biocontrol microbes will be tested for pathogenicity on cyst nematodes. Effects of tillage on reproduction of H. glycines will be examined in long-term tillage trials with Tony Vyn (AGRY). Reproduction was lower under no-tillage conditions than under moldboard plowing with secondary tillage. Tests will investigate why this reduction in nematode reproduction occurs. Soil physical or soil biological factors will be tested for their role in this reduced nematode reproduction. It will be determined whether soil parameters that confer this nematode suppression can be exploited for sustainable management of the nematode. We (in collaboration with W.G. Johnson) investigate the role of winter annual weeds in the population dynamics of H. glycines. 2. Association of SDS and soil physical, chemical and biological characteristics Sudden death syndrome of soybean is a disease with increasing incidence in the north central region. Some parameters conducive for disease development have been identified and the area of risk identified (Scherm and Yang, 1999). There is little information about the interaction of F. solani f.sp. glycines with other soil organisms and soil texture of a particular field. 3. Interaction of H. glycines and F. solani f.sp. glycines We confirmed that H. glycines is the key factor to increase SDS severity (Xing and Westphal, 2006). The future project will investigate the possible mode of action of this interaction. Since nematode populations of different races exist, these will be used to infest the race differential test assortment of soybean cultivars with F. solani f.sp. glycines. Disease development and severity will be evaluated. This will generate information if the nematode and the fungus can damage the plants synergistically. Also, it will be explored if one pathogen can break the resistance present in one soybean cultivar to another pathogen, the question will be asked if nematode infection can break resistance to SDS. 4. Management of soil-borne diseases of watermelon Watermelons are prone to damage by many soil-borne disease problems. While several pathogens can infect watermelon roots, root knot nematodes are among the most notorious infective agents and cause damage almost every year. This project will evaluate the damage potential and possible mitigation of risk for damage by soil-borne organisms. In addition to studies of root knot nematodes on watermelon, a late season vine decline problem will be examined. Mature watermelon vine decline (MWVD) has caused problems in some years in South Indiana. Plant cultural techniques are suspected to be partly involved in the development of this problem. We have demonstrated that this soil-borne disease is biologically incited. Further studies will investigate the etiology of the disorder and possible mitigation.

Progress 10/01/06 to 09/30/11

Outputs
OUTPUTS: An online review of the causes and management of sudden death syndrome in soybean has been distributed on the web. Research papers on resistance of soybean cultivars to nematodes (Heterodera glycines and Meloidogyne incognita) and impact of microbial inoculants on growth and fruit yield of watermelons have been published. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Soybean farmers, plant pathologists, nematologists PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Greenhouse and field experiments were conducted to evaluate the resistance of soybean varieties (groups II to IV) to the nematode species Meloidogyne incognita and Heterodera glycines. high yielding soybean varieties with resistance and tolerance to Meloidogyne incognita were identified. Watermelon seedlings grown in soilless potting mixes were inoculated with two commericial inocula of mycorrhizal fungi. These treatments increased the yield of early fruits and improved growth in soils that were infested with the nematode Medoidogyne incognita.

Publications

  • Robinson, A. F., A. Westphal, C. Overstreet, G. B. Padgett, S. M. Greenberg, T. A. Wheeler, and S. R. Stetina. 2008. Detection of suppressiveness against Rotylenchulus reniformis in soils from cotton (Gossypium hirsutum) fields in Texas and Louisiana. Journal of Nematology 40:35-38.
  • Kruger, G. R., L. J. Xing, A. LeRoy, and A. Westphal. 2008. Meloidogyne incognita resistance in soybean under Midwest conditions. Crop Science 48:716-726. Online: doi:10.2135/cropsci200704.0196.
  • Westphal, A., J. J. Camberato, N. L. Snyder, and L. J. Xing. 2008. Effects of inoculations with mycorrhizal fungi of soilless potting mixes during transplant production on watermelon growth and early fruit yield. HortScience 43:354-360.
  • Westphal, A., T. S. Abney, L. J. Xing, and G. Shaner. 2008. Sudden death syndrome of soybean. The Plant Health Instructor. Online, doi:1.1094/PHI-I-2008-0102.01.
  • Xing, L. J. and A. Westphal. 2007. Inhibition of Fusarium virguliforme by prokaryotes in vitro. Subtropical Plant Sciences 59:24-29.


Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: National and international recognition for his studies of suppressive soils is reflected in the numerous requests for his contributions in various publication formats. For example, he was invited to publish a review article of methods for detecting and describing soil suppressiveness against plant-parasitic nematodes (Westphal, 2005), an article that has become a key resource for nematologists interested in biological control of nematodes. A press release on this article was published on July 1, 2005 (http://news.uns.purdue.edu/UNS/html4ever/2005/050701.Westphal.nema.h tml). Dr. Westphal's current work generates large interest and thus he has been invited to present at several symposia this summer. He will present at the joint Annual meeting of the Society of Nematologists and the American Phytopathological Society in summer 2007. Dr. Westphal's work generates interest outside of his disciplinary societies, e.g., he was invited to present at the Annual meeting of the Ecological Society of America in summer 2007. He has an open invitation from the Suez Canal University in Egypt to visit and to consult on the management of soil-borne disease problems in that country. TARGET AUDIENCES: Plant pathologists and entomologists

Impacts
The soybean cyst nematode (SCN) and sudden death syndrome (SDS) are damaging soybean synergistically. Traditional management practices for SCN and SDS are insufficient to ensure sustainability of soybean-corn production systems. Limited effectiveness in reducing disease pressure and the variability of the causal organism of the disease complex put the sustainability of usefulness of host plant resistance at risk. Dr. Westphal discovered dual-suppressive soils against this disease complex. This is an exceptional novel report of soils that suppress a plant disease complex because no single example of such has been reported previously. Soil suppressiveness developed against the disease complex sudden death syndrome under continuous monoculture of soybean in non-tilled fields in non-treated field plots, whereas preseason-fumigated and re-infested plots became highly conducive. Elucidating the mode of action that allows for the concomitant suppression of a nematode and a fungus will generate novel and fundamental information on how pathogens interact and other microorganisms within soil. Dr. Westphal has been investigating the effect of winter annual weeds on soybean cyst nematode populations with Dr. William Johnson (BTNY). In this project, it was confirmed SCN reproduces on winter annual weeds during Indiana winter conditions.

Publications

  • Creech, J. E., J. Faghihi, V. R. Ferris, A. Westphal, and W. G. Johnson. 2007. Influence of intraspecific henbit (Lamium amplexicaule) and purple deadnettle (Lamium purpureum) competition on soybean cyst nematode (Heterodera glycines) reproduction. Weed Science: In Press.
  • Creech, J. E., J. B. Santini, S. P. Conley, A. Westphal, and W. G. Johnson. 2007. Purple deadnettle (Lamium purpureum) and soybean cyst nematode (Heterodera glycines) response to cold temperature regimes. Weed Science: In Press.
  • Kruger, G. R., Xing, L. J., Santini, J., and A. Westphal. 2007.Distribution and Damage Caused by Root-Knot Nematodes on Soybean in Southwest Indiana. Plant Health Progress: In Press.
  • Kruger, G. R., L. J. Xing, A. LeRoy, and A. Westphal. 2007. Usefulness of Meloidogyne incognita resistance in soybean under Midwest conditions. Crop Science: In Press.
  • Creech, J. E., A. Westphal, V. R. Ferris, J. Faghihi, T. J. Vyn, J. B. Santini, J. B., and W. G. Johnson. 2007. Influence of winter annual weed management and crop rotation on soybean cyst nematode (Heterodera glycines) and winter annual weeds. Weed Science: In Press.
  • Creech, J. E., J. S. Webb, B. G. Young, J. P. Bond, S. K. Harrison, V. R. Ferris, J. Faghihi, A. Westphal and W. G. Johnson. 2007. Development of soybean cyst nematode (Heterodera glycines) on henbit (Lamium amplexicaule) and purple deadnettle (Lamium purpureum). Weed Technology: In Press.


Progress 10/01/05 to 09/30/06

Outputs
One hundred soils were tested for suppressiveness based on previously developed tests (Westphal and Becker, 1999, 2001; Westphal, 2005). A number of suppressive soils were identified with low nematode reproduction compared to others. Microbes associated with cysts in these suppressive soils will be isolated. Promising biocontrol microbes will be tested for pathogenicity on cyst nematodes. Effects of tillage on reproduction of H. glycines will be examined in long-term tillage trials with Tony Vyn (AGRY). It will be determined whether soil parameters that confer this nematode suppression can be exploited for sustainable management of the nematode. We (in collaboration with W.G. Johnson) investigated the role of winter annual weeds in the population dynamics of H. glycines. The potential for reproduction of H. glycines on weed roots under field conditions was confirmed (Creech et al. 2005). The hypothesis of transferability of soil suppressiveness against H. glycines was confirmed under greenhouse and field conditions (details under IND055075G) Sudden death syndrome of soybean is a disease with increasing incidence in the north central region. Some parameters conducive for disease development have been identified. There is little information about the interaction of F. solani f.sp. glycines with other soil organisms and soil texture of a particular field. A dual-suppressive soil was identified that reduces SDS severity and SCN reproduction (details under IND055075G). We confirmed that H. glycines is the specific key factor to increase SDS severity and that not every plant-parasitic nematode has SDS severity increasing effects (Xing and Westphal, 2005, 2006). The future project will investigate the possible mode of action of this interaction. It will be explored if one pathogen can break the resistance present in one soybean cultivar to another pathogen, the question will be asked if nematode infection can break resistance to SDS. Watermelons are prone to damage by many soil-borne disease problems. While several pathogens can infect watermelon roots, root knot nematodes are among the most notorious infective agents and cause damage almost every year. Cultural methods for root knot nematode suppression are currently being evaluated.

Impacts
Awareness of soil-borne diseases is greatly increased. Management tactics for soil-borne diseases are being improved and awareness of the most effective use of information about the biology of the pathogens and pests is fostered.

Publications

  • Creech, J. E., W.G. Johnson, J. Faghihi, V. Ferris and A. Westphal. 2005. First report of soybean cyst nematode reproduction on purple deadnettle under field conditions. Crop Management doi:10.1094/CM-2005-0715-01-BR.
  • Xing, L.-J., and A. Westphal. 2005. A method for field infestation with Meloidogyne incognita. Journal of Nematology 37:500-503.
  • Xing, L.-J., and A. Westphal. 2006. Interaction of Fusarium solani f. sp. glycines and Heterodera glycines in sudden death syndrome of soybean. Phytopathology 96:763-770.


Progress 10/01/04 to 09/30/05

Outputs
The program focuses on the ecology of soil-borne pathogens and pests. Dr. Westphal investigates aspects of interactions of soil-borne organisms in the systems of (1) sudden death syndrome of soybean (SDS), (2) on soybean cyst nematodes (SCN), (3) root knot nematodes (RKN), and (4) etiology of mature watermelon vine decline (MWVD). (1) Ecology and biological control of sudden death syndrome of soybean (SDS) The crucial role of SCN on the severity of SDS was demonstrated. Field methods have been developed that allow collecting consistent data. Other projects in this program portion evaluate the effects of different crop sequences on root health in fields with a history of SDS. Soybean crops in a corn-soybean rotation had mediocre root health compared to that in biocide-treated soil that was included in these tests. Investigations continue on how this impacts development of SDS and soybean yield. Field infestation methods are adapted to this kind of study. Greenhouse and laboratory methods have been developed to test biocontrol organisms for potential against the fungal pathogen. Of four commercially available bacterial biocontrol organisms two exerted fungal inhibition in vitro. Additional studies investigate the role of plant nutrients in this complex of root health questions. (2) See IND55075G 0193505. (3) Root knot nematodes on Indiana crops Root knot nematodes are a notorious problem in the southern part of Indiana where watermelons are grown. Growers are increasing their awareness on aspects of nematodes. New chemistry or application timing and technique for known chemistry are investigated. Potential improvements of crop sequences that are currently based on host crops of the southern root knot nematode by incorporating resistant cultivars of the host crops or by enriching cover crop periods with nematode-antagonistic plants are ongoing. A German oilseed radish cultivar with resistance against the southern root knot nematode, that infects watermelon in South Indiana, has shown potential as a cover crop under simulated field conditions. The damage potential of this nematode in soybean in Indiana has been documented. Threshold level information for the nematode on watermelon has been generated. (4) Mature Watermelon Vine Decline (MWVD) Various hypotheses for a late-season vine collapse have been proposed. We demonstrated that the cause of this problem is biological. In field microplots, we found that methyl bromide is the most effective fumigant in reducing this disease. In greenhouse experiments, soil treated at 60 degrees C heat treatment for 30 minutes no longer exhibited MWVD). Potential watermelon pathogens from watermelon roots were isolated and are currently tested for pathogenicity on watermelon. Colonization rates were similar like for the standard host onion.

Impacts
The expected impacts are subdivided into: (1) improved understanding of the infection conditions of the fungal pathogen of SDS to improve management of the disease; (2) see IND55075G 0193505; (3) improve management of RKN by improved variety selection and implementation of nematode-antagonistic cover crops; (4) understand the etiology of MWVD.

Publications

  • Xing, L. J. and A. Westphal 2005. Development of sudden death syndrome in two soybean lines in field microplots infested with Fusarium solani f. sp. glycines and Heterodera glycines. Presented at the Annual meeting of the Society of Nematologists, Ft. Lauderdale, FL, July 9-13, 2005.
  • Kruger, G. and A. Westphal 2005. Damage by Meloidogyne spp. to soybean in Indiana. Presented at the Annual Meeting of the Society of Nematologists, Ft. Lauderdale, FL, July 9-13, 2005.
  • Xing, L. J. and A. Westphal 2005. In vitro test for inhibition of Fusarium solani f. sp. glycines with biocontrol agents. Phytopathology 95:S184.


Progress 10/01/03 to 09/29/04

Outputs
The program focuses on the ecology of soil-borne pathogens and pests. Soil-borne plant pathogens interact with each other and with soil-borne non-pathogenic microorganisms. Dr. Westphal investigates these aspects in sudden death syndrome of soybean (SDS) and the soybean cyst nematode. The program parts are: Biocontrol of SDS, biocontrol of soybean cyst nematode, etiology of MWVD and importance of root knot nematodes on Indiana crops. Biocontrol of SDS. The identification of antagonists against Fusarium solani f.sp. glycines, causal organism of SDS, will improve management strategies for SDS. Biocontrol organisms could augment current management options for SDS. This disease is of increasing importance throughout the North Central Region. Symptoms - root rot, leaf drop and premature death -are exacerbated by wet soil at the beginning of reproductive stages of soybean, and lead to substantial yield loss. Commercial biocontrol organisms active against soil-borne fungi are tested in vitro and in the greenhouse for their antagonistic potential against F. solani f.sp. glycines. In a first screen, two of four biocontrol organisms inhibited growth of the fungal pathogen in vitro and had activity against a number of strains of the pathogen. Candidate biocontrol products are currently evaluated in greenhouse and field tests. Biocontrol of soybean cyst nematodes. See: IND055075G, 0193505. Etiology of MWVD. MWVD reduces yields due to premature death of the plant and sun exposure of the fruit; it has occurred in southern Indiana since the mid-1980s. In greenhouse and field experiments, various non-selective and selective treatments have been employed to elucidate the nature of the disorder. Initial tests indicated that the disorder is biologically incited. In a field test, soil fumigation (in particular soil fumigation with methyl bromide) increased plant growth in comparison with the non-treated control. In greenhouse experiments, when problem soil was heat-treated at 60 degree C or hotter for 30 minutes before planting, MWVD was eliminated. Rhizopycnis vagum, a potential watermelon pathogen previously not reported in Indiana, was isolated from symptomatic watermelon roots in greenhouse tests after designing modified isolation procedures. Root knot nematodes in southern Indiana crop sequences. Dr. Westphal confirmed root knot nematodes on soybean and corn, the rotational crops of watermelon. The consideration of the entire crop sequence in management decisions is essential since chemical nematode control options are difficult to implement in southern Indiana: soils are often too wet and too cold in spring to permit effective treatments. Dr. Westphal raises awareness of this crop sequence-encompassing problem and works on improvement of this crop sequence design. In one project, he tests soybean cultivars for resistance to root knot nematodes. This will provide the option to growers to use nematode-resistant soybean cultivars rather than those that are susceptible in fields with known infestations with root knot nematodes. This is the foundation for an integrated management of the root knot nematodes in a sequence rather than single-crop approach.

Impacts
Studies of the interaction of soil-borne pathogens and beneficial organisms will improve the implementation of sustainable management options for soil-borne diseases.

Publications

  • Xing, L.J. and A. Westphal 2004. Effect of soybean cyst nematode, soil moisture and infestation level on sudden death syndrome of soybean. Phytopathology 94:S112


Progress 10/01/02 to 09/30/03

Outputs
Westphal's program focuses on the ecology and management of soil-borne diseases. Biocontrol of Sudden Death Syndrome of soybean: Sudden Death Syndrome (SDS), caused by Fusarium solani f.sp. glycines, recently renamed Fusarium virguliforme, is a soil-borne disease of increasing importance throughout the North Central Region of the United States. This late season disease is a combination of a root rot, leaf drop, and premature death of the soybean that leads to substantial yield loss. In this project, commercial biocontrol organisms against soil-borne fungi are tested in vitro and in the greenhouse for antagonistic potential against Fusarium solani f.sp. glycines. Tester strains are placed together with strains of the fungal pathogen. Growth patterns are compared under the influence of different biocontrol organisms. Westphal's group developed a greenhouse bioassay that will allow testing of biocontrol organisms for their potential to reduce severity of SDS. In addition, soybean field soils are tested for soil suppressiveness against the disease. Biocontrol/soil suppressiveness against the soybean cyst nematode: The soybean cyst nematode, Heterodera glycines, is one of the most important soil-borne problems of soybean throughout the soybean belt. Effective crop sequences and selection of resistant cultivars provide some relief from the pest. Populations of the cyst nematode can overcome particular sources of resistance in soybean germplasm. This places success of management of the cyst nematode with the use of host plant resistance at risk. Natural biological control has been identified for close relatives of the soybean cyst nematode. In such soils, nematode population densities typically remain at low levels and cause only limited plant damage. Westphal developed several techniques for detecting and monitoring soil suppressiveness against cyst nematodes. Currently, >100 soils in the North Central region are surveyed for suppressiveness against the soybean cyst nematode. Etiology of the Mature Watermelon Vine Decline (MWVD): A late season vine collapse, the mature watermelon vine decline (MWVD), has occurred in southern Indiana since the mid-1980. MWVD leads to quantitative and qualitative yield losses. In greenhouse and field experiments, the growth response following the application of various non-selective and selective treatments have indicated that the disorder is biologically incited. In a field test, soil fumigation (in particular soil fumigation with methyl bromide) increased plant growth in comparison to the non-treated control. In greenhouse experiments, heat treatments of 60 degrees Celcius or higher for 30 minutes eliminated MWVD form problem soil from near Vincennes. Candidate fungal plant pathogens were isolated from symptomatic watermelon roots in greenhouse tests after designing modified isolation procedures. Application of Koch's Postulates to demonstrate pathogenicity of these fungi is in progress. This project is supported by soybean grower groups (United Soybean Board, North Central Research Program, and the Indiana Soybean Board), the National Research Initiative-Competitive Grants Program within CSREES, and in-house.

Impacts
Studies of the interaction of soil-borne pathogens and beneficial organisms will improve the implementation of sustainable management options for soil-borne diseases.

Publications

  • Xing, L.J., Santini, J.B., and A. Westphal 2003. Soybean root necrosis in response to infestation levels of Fusarium solani f.sp. glycines. Abstract presented at the North Central APS meetings, East Lansing, MI, June 25-27, 2003.
  • Westphal, A., and D.S. Egel 2003. Evidence for biological nature of mature watermelon vine decline. Abstract presented at the 8th International Congress of Plant Pathology, Christchurch, NZ Proceedings ICPP Vol. 2:259.


Progress 10/01/01 to 09/30/02

Outputs
Westphal's program focuses on the ecology of soil-borne diseases. Biocontrol of Sudden Death Syndrome of soybean: Sudden Death Syndrome (SDS), caused by Fusarium solani f.sp. glycines, is a soil-borne disease of increasing importance throughout the North Central Region of the United States. This late season disease is a combination of a root rot, leaf drop and premature death of the soybean that leads to substantial yield loss. In this project, commercial biocontrol organisms against soil-borne fungi are tested in vitro and in the greenhouse for antagonistic potential against Fusarium solani f.sp. glycines. First, tester strains are placed together with strains of the fungal pathogen on different media plates. Growth patterns are compared under the influence of different biocontrol organisms. Secondly, soybean field soils are tested for soil suppressiveness against the disease. Biocontrol/soil suppressiveness against the soybean cyst nematode: The soybean cyst nematode, Heterodera glycines, is one of the most important soil-borne problems of soybean throughout the soybean belt. Effects of crop sequence and cultivar selection provide some relief from the pest. Diversity of nematode populations makes nematode damage a continuous risk for soybean production. The nematode occurs in different populations with varying virulence to sources of host plant resistance. A race or HG-type system has been developed to help in cultivar selection. Natural biological control has been identified for close relatives of the soybean cyst nematode. In such soils, nematode population densities typically remain at low levels and cause only limited plant damage. Several biocontrol organisms have been proposed. Westphal developed several techniques for detecting and monitoring soil suppressiveness against cyst nematodes during his dissertation research. These techniques will be used in this project. Etiology of the Mature Watermelon Vine Decline (MWVD): A late season vine collapse, the mature watermelon vine decline (MWVD) has occurred in southern Indiana since the mid-1980. MWVD leads to quantitative and qualitative yield loss due to premature death of the plant and due to sun exposure of the fruit. Westphal's program systematically explores the nature of this disorder. In greenhouse and field experiments, the growth response following the application of various non-selective and selective treatments have indicated that the disorder is biologically incited. In a field test, soil fumigation (in particular soil fumigation with methyl bromide) increased plant growth in comparison to the non-treated control. In greenhouse experiments, heat treatments of higher and equal to 60 degree Celcius for 30 minutes eliminated MWVD from Vincennes problem soil. Candidate fungal plant pathogens were isolated from symptomatic watermelon roots in greenhouse tests after designing modified isolation procedures. Koch's Postulates to demonstrate pathogenicity of this fungus are in progress. Support is provided by soybean grower groups (United Soybean Board, Indiana Soybean Board), the National Research Initiative-Competitive Grants Program within CSREES, and in-house support.

Impacts
Studies of the ecology of soil-borne diseases will improve the implementation of sustainable management options.

Publications

  • No publications reported this period