Progress 08/01/10 to 07/31/13
Outputs
Target Audience: Target Audience and Efforts Results of our experiments have had a positive impact for regulators (Idaho State Department of Agriculture and USDA-APHIS) and potato industry (Idaho Potato Commission, Northwest Regional Potato Consortium, and National Potato Council) by informing them of research progress for eradication of PCN. Our research has assured that previously quarantined acreage remains PCN-free, and has helped regulators and the potato industry deal with current infestations and prepare for future risks. Beneficiaries of this project have been growers affected by the PCN quarantine, as well as the Idaho potato industry as a whole by helping to maintain market confidence in the efficacy and durability of the PCN eradication program, and, secondarily, this project has benefited the large number of Idahoans who are involved with all aspects of potato processing, marketing, shipping, etc. A national stakeholder advisory committee held monthly teleconferences, this group consisted of USDA-APHIS and USDA-ARS representatives (located in ID, WA, NY, and Beltsville MD), ISDA, NYSDA, potato industry representatives, the scientific liason for the OR-ID-WA potato commissions, and university scientists from states with potato cyst nematode concerns (ID, NY, OR). A Northwest regional subset of the above group held monthly teleconferences, focusing on potato cyst nematode issues of particular importance to the Pacific Northwest including Idaho. The three main players (USDA-APHIS, University of Idaho, potato industry) remained in constant email contact as well as monthly teleconference calls to ensure smooth implementation of eradication strategies, both for the current methyl bromide fumigation effort as well as for proposed alternative eradication strategies. The scientific liason for the three PNW potato commissions (ID, OR, WA) was also involved in the teleconferences. Thus, a standing mechanism has been in place to ensure effective communication of project results. Information and research results have been presented about the problem through workshops and seminars at the Idaho Potato Conference and at the Idaho Association for Plant Protection and biannual meetings with industry, regulators, and researchers, and annual scientific conferences (American Phytopathological Society, and Society of Nematology). Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? PI L. M.Dandurandtraveled to CPHST Beltsville Laboratory to obtain PCN Training in DNA extraction and molecular diagonistics.September 27, 2011. How have the results been disseminated to communities of interest? Results of our experiments have had a positive impact for regulators (Idaho State Department of Agriculture and USDA-APHIS) and potato industry (Idaho Potato Commission, Northwest Regional Potato Consortium, and National Potato Council) by informing them of research progress for eradication of PCN. Our research has assured that previously quarantined acreage remains PCN-free, and has helped regulators and the potato industry deal with current infestations and prepare for future risks. Beneficiaries of this project have been growers affected by the PCN quarantine, as well as the Idaho potato industry as a whole by helping to maintain market confidence in the efficacy and durability of the PCN eradication program, and, secondarily, this project has benefited the large number of Idahoans who are involved with all aspects of potato processing, marketing, shipping, etc. A national stakeholder advisory committee held monthly teleconferences, this group consisted of USDA-APHIS and USDA-ARS representatives (located in ID, WA, NY, and Beltsville MD), ISDA, NYSDA, potato industry representatives, the scientific liason for the OR-ID-WA potato commissions, and university scientists from states with potato cyst nematode concerns (ID, NY, OR). A Northwest regional subset of the above group held monthly teleconferences, focusing on potato cyst nematode issues of particular importance to the Pacific Northwest including Idaho. The three main players (USDA-APHIS, University of Idaho, potato industry) remained in constant email contact as well as monthly teleconference calls to ensure smooth implementation of eradication strategies, both for the current methyl bromide fumigation effort as well as for proposed alternative eradication strategies. The scientific liason for the three PNW potato commissions (ID, OR, WA) was also involved in the teleconferences. Thus, a standing mechanism has been in place to ensure effective communication of project results. Information and research results have been presented about the problem through workshops and seminars at the Idaho Potato Conference and at the Idaho Association for Plant Protection and biannual meetings with industry, regulators, and researchers, and annual scientific conferences (American Phytopathological Society, and Society of Nematology). What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Pluronics and alginate-based potato seedpiece coating trials were done to evaluate whether Pluronics technology (BASF) would be useful for formulation of the biocontrol fungi. Hyphal growth (in soil) of T. harzianum formulated as pellets either with Pluronics or with our standard alginate-bran method was monitored in a time-course study. The Pluronics method did not enhance either radial colony growth or sporulation of the biocontrol fungus, and because it is also a more expensive technology it will not be investigated further. Greenhouse experiments are underway to evaluate the most effective rate for application of the biological control fungi, Trichoderma harzianum or Plectosphaerella cucumerina against PCN. Russet Burbank was planted into soil infested with either T. harzianum or P. cucumerina at a rate of 80 lb/ac, 160 lb/ac, or 320 lb/ac. After 16 wk, nematode reproduction will be evaluated. The efficacy of the bacterial biological control agents Delftia, Variovorax and Pseudomonas sp. were evaluated against PCN. In the PCN only (root dipped in sterile water) treatment an average of 15 nematodes infected the roots, whereas, 62 nematodes were recovered from roots grown in non-infested soil. The bacterial biocontrol agent Delftia greatly reduced total number of nematodes found in potato roots whether plants were root dipped or grown in infested soil. Only one nematode was observed to infect potato roots in these two treatments. Variovorax also decreased nematode infection but only when plants were grown in infested soil where zero nematodes were observed. Pseudomonas treated plants, whether root dipped or planted into infested soil had fewer nematodes than the control but did not reduce infection by the nematode as much as the other two bacterial species. Further experiments to test the ability of these bacterial biocontrol agents to reduce reproduction of the nematode will be conducted. The trap crop/suicide hatch qualitiesof S. sisymbriifolium (sticky nightshade) combined with biocontrol agents were assessed to see if their effects were additive or synergistic. To determine the effect of three different cropping systems (potato, sticky nightshade or soil only-fallow) on population of PCN, soil, amended with either P. cucumerina, or T. harzianum or non-amended, was infested with cysts of PCN and planted with either potato or sticky nightshade. The fallow treatment was amended with the biocontrol agent but not planted. After 21 weeks, viability and hatch of eggs retrieved from cysts that were used to infest at initiation of the experiment was determined. The highest number of viable eggs were retrieved from the soil only treatment. The least number of viable eggs were found in cysts retrieved from the soil only treatment amended with T. harzianum. P. cucumerina did not significantly reduce viability of eggs compared to the soil only treatment. Both sticky nightshade and potato reduce viability of eggs compared to the soil only treatment, but there was no difference in viability between potato and sticky nightshade. In addition of the biological control agents with either potato or sticky nightshade did not further reduce viability of eggs. Juveniles hatched only from the soil-alone treatment, and hatching was greatly reduced in soil-only amended with T. harzianum but not with P. cucumerina. Eggs did not hatch from either potato or sticky nightshade whether or not amended with the biological control fungi. This may indicate some level of quiescence in viable eggs after exposure to one growth cycle of either susceptible host or trap crop. Some of the cysts retrieved have been placed into bioassay to determine their reproductive ability. In bioassay experiments, S. sisymbriifolium almost entirely eliminated reproduction of the nematode population on the succeeding potato crop. We have observed similar results in other laboratory and greenhouse experiments. Cysts were placed in soil containing Brassica juncea, Brassica napis, or Sinapis alba meal at a rate of either 1 ton/acre, 4 tons/acre, or non-amended soil, and incubated at 18?C for two weeks in a completely randomized design. Hatching of PCN was significantly reduced by Brassica juncea at both levels and Brassica napis at 4 tons/acre. There was no significant difference between Brassica napis at 4 tons/acre and Sinapis alba at either rate. After the incubation/fumigation period, 10 cysts were placed in soil (2:1 sand:soil mix) and planted with 4-week-old Russett Burbank tissue culture plantlets. B. juncea at both rates greatly reduced cyst numbers compared to the control. Fumigation with S. alba meal did not reduce average numbers of extracted cysts. Whereas B. napus had fewer cysts at the high rate (4t/acre) compared to the low rate (1t/acre). These results are in agreement with what we observed from the hatching assays. Field 2012 research trials of biocontrol and biofumigant agents were established in a PCN infested field in Idaho Falls, ID with permission from USDA-APHIS. The field site was initially sampled for cysts (April 2012) prior to fumigating with MeBr by USDA-APHIS. After fumigation, the field plot was established in May 2012. Treatments, mustard meal (4 tons/acre), T. harzianum (38kg/acre), P. cucumerina (38kg/acre), or MeBr were applied to the field site in a completely randomized block design with four blocks per treatment. Plots, with the exception of those with biofumigant were planted with barley, a non-host of PCN. Six weeks after treatments were added, a mid-growing season sampling was conducted (July 2012). Each plot was again sampled for cysts and levels of biocontrol agent in soil and rhizosphere. Plants were collected to determine infection levels of the biocontrol agents. We conducted bioassays from field cysts collected in May when we set up the experiment, from field cysts sampled in July, and from cysts collected in August. We found 14 cysts from bioassay of May sampled cysts and four cysts from the methyl bromide treated plots in the July sampling, and no cysts from the August sampling. The field site for this trial was the same field site that was used last year for field testing of mustard meal and 2 biological control agents against PCN, with an additional Solanum sisymbriifolium treatment. The field site was used for the 2nd year field testing of mustard meal, Trichoderma harzianum, and Plectosphaerella cucumerina. The field site has undergone a 2nd cycle of fumigation by USDA-APHIS with methyl bromide in May 2013. Soil samples from each plot were taken 3 times over the summer (July and August). Cysts from each soil sample will be extracted and enumerated. Viability of eggs will be determined with meldola’s blue, and hatching of eggs will be determined through standard hatching assays. In addition, cysts extracted from each experimental plot will be placed into a bioassay following USDA-APHIS protocol under greenhouse conditions to determine their reproductive ability. We are currently evaluating the number of cysts from each plot and determining there viability, ability to hatch and reproductive ability (bioassay). The results of soil and root plating (August 20, 2013 sampling) indicate that both P. cucumerina and T. harzianum proliferated and persisted in soil and on roots of barley similar to last year’s results. This indicates that both of these agents can compete under field conditions.
Publications
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2012
Citation:
Dandurand, L. M. October 2012. PCN Eradication Strategies Update. Biannual USDA-APHIS PCN Meeting. Pasco, WA.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2012
Citation:
Dandurand, L. M., November 7-8, 2012. Biology and control of potato cyst nematode. 2012 Idaho Association of Plant Protection, Jerome, ID.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2012
Citation:
Dandurand, L. M., October 18-19, 2012. Trap crop related research at the UI PCN laboratory. UI Potato Team Retreat, Albion, ID.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2012
Citation:
Dandurand, L. M. July 2012. Eradication of Pale Cyst Nematode. Video Conference with Infested Field Grower Group. Idaho Falls, ID.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2010
Citation:
Boydston, R.A., Hojtahedi, H., Bates, C., Zemetra, R., and Brown, C.R. 2010. Weed hosts of Globodera pallida from Idaho. Plant Disease 94:918.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2013
Citation:
Dandurand, L. M., Brown, C. R., Filip, C. J., Gajjar, P. 2013. Potential of Solanum sisymbriifolium as a trap crop for the control of the pale cyst nematode, Globodera pallida. Society of Nematology, Meeting Abstracts
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2013
Citation:
Dandurand, L. M., Knudsen, G. R., Brown, C. R., Filip, C. J., Gajjar, P. 2013. Potential of Solanum sisymbriifolium and the biological control fungi, Trichoderma harzianum and Plectosphaerella cucumerina to control Globodera pallida, the pale cyst nematode.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Dandurand, L.M. 2013. Novel Eradication Strageties for Pale Cyst Nematode. Potato Progress vol. 13 (10). www.nwpotatoresearch.com
- Type:
Journal Articles
Status:
Published
Year Published:
2011
Citation:
Gao, X., King, B., Worapong, J., Johnson, J.B., and Zemetra, R.S. 2011. Hatching patterns of field and greenhouse populations of Globodera pallida from Idaho, USA. International Journal of Nematology. 21(1):1-6.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2011
Citation:
Gao, X., Price, W.J., Bates, C., VanSickle, M.J., Worapong, J., Johnson, J.B., and Zemetra, R.S. 2011. Mustard seed meal reduces viability and hatching of Globodera pallida. Society of Nematologists Meeting abstracts pg. 85-86.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2010
Citation:
Gao, X., Worapong, J., Johnson, J.B., and Zemetra, R.S. 2011. Improving reproduction of the Idaho population of the pale cyst nematode, Globodera pallida, for use in studies to control and/or eradicate PCN in Idaho. American Phytopathological Society abstracts
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2010
Citation:
Gao, X., Price, W.J., Worapong, J., King, E., Johnson, J.B., and Zemetra, R.S. 2010. The effect of mustard seed meal on viability of Globodera pallida. Society of Nematologists Meeting abstracts pg. 57.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2012
Citation:
Knudsen, G. R., and L. M. Dandurand. 2012. Predictive model of eradicative and management strategies for pale cyst nematode, APS Annual Meeting, Providence, RI.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2012
Citation:
Worapong, J., J. Johnson, and L. M. Dandurand. 2012. Potential of nematophagous fungi for control of the pale cyst nematode, Globodera pallida, APS Annual Meeting, Providence, RI.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2011
Citation:
Worapong, J., Johnson, T., Gao, X., Kuhl, J.C., Bates, C., Johnson, J.B., and Zemetra, R.S. 2011. Identification of five fungal species isolated from non-viable eggs of a sing Globodera pallida cyst based on a polyphasic approach. Society of Nematologists Meeting abstracts pg. 169-170.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2010
Citation:
Worapong, J., Bates, C., Gao, X., Meacham, T.E., Johnson, J.B., and Zemetra, R.S. 2010. Screening of microorganisms associated with cysts of Globodera pallida isolated from southern Idaho fields. Society of Nematologoists Meeting abstracts pg. 120-121.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2013
Citation:
Dandurand, L. M. March 2013. PCN Eradication Strategies 2012 Update. Biannual USDA-APHIS PCN Meeting. Boise, ID.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2013
Citation:
Dandurand, L. M. January 2013. Pale Cyst Nematode: Biology and Eradication Strategies. Idaho Potato Conference. Pocatello, ID.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2013
Citation:
Dandurand, L. M. January 2013. Trap Crop Research for PCN Eradication. Idaho Potato Conference. Pocatello, ID.
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Progress 08/01/10 to 07/31/11
Outputs
OUTPUTS: The UI-Potato Cyst Nematode project goals include developing protocols for the production of Globodera pallida (wPCN) cysts for use in control and eradication studies, and to conduct research on both short term and long term control strategies for wPCN. A major challenge for the program initially was the production of cysts from field collected cysts from southern Idaho. This obstacle has been overcome and in the past 12 months over 29,000 cysts have been produced for use in control and eradication studies. With each successive generation of cyst production, the Idaho-PCN population's reproduction rate improved. At the onset, the average egg hatching rates of PCN field cysts was 2.8% in 2008. In subsequent generations there was an increase in hatching rate from 14.5% for the F1 generation to 44.5% in the F2 generation. This increase is likely due to improvement in the viability of the eggs in the cysts and improvement of the culturing of the Idaho-PCN population. One challenge still remains in understanding the life cycle of wPCN and that is the duration of diapause required for hatching. A twelve month study is underway to determine the optimum diapause period for the Idaho strain of wPCN. This should further increase the production of wPCN cysts for research. In terms of short term control strategies, two areas of research have been pursued, bio-control and biofumigation. In the area of biocontrol, both fungi and bacteria were isolated from field derived cysts that may have potential use as biocontrol agents. Evaluation of two of the bacterial strains showed both reduced viability and hatching of wPCN after infection. A single cyst that contained only non-viable eggs provided five different fungal strains. Phytopathogenicity tests of the isolated fungi showed that they were not pathogenic to Desiree or Russet Burbank potato cultivars. Testing Brassica juncea seed meal as potential bio-fumigant on PCN cysts showed a reduction in both viability and hatching of wPCN after exposure of the cysts to seed meal for one to three weeks. At 3 weeks of cyst exposure egg viability was 67.2% in the control, and 44.7-50.7% in the other treatments. The corresponding egg hatching rate was 9.1% in the controls and 0.5 - 1.4% for the other treatments. Evaluation of three commercial soil fumigants for their potential as replacements for methyl bromide showed that all three were effective in reducing hatching of wPCN. Screening of potato germplasm and breeding lines for resistance to wPCN continues with several genotypes showing promise as part of a long term control strategy. The project has also facilitated research in the area of identification of trap crops/species, alternative host of wPCN, and isolation of the diffusate factor involved in hatching inducement of wPCN. PARTICIPANTS: The research project conducts collaborative research with the following individuals/research programs: R. Navarre - USDA-ARS Prosser - diffusate studies and trap crops; R. Boydston- UDDA-ARS Prosser - alternative host studies; R. Novy -USDA-ARS Aberdeen - breeding for wPCN resistance; C. Brown - USDA-ARS Prosser - breeding for wPCN resistance. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Due to the initial low rate of cyst production, extended life cycle of wPCN due to its diapause period, and the level of demand on available wPCN cysts, experiments associated with this project were delayed. With the increase in production of cysts in summer 2009 and 2010 experiments could be initiated. The extended life cycle required between generation (4 months for hatch to harvest and 3-6 months diapause has also delayed experiments. In May of 2011 program director Robert Zemetra left the University of Idaho for a position at Oregon State University leading to further delays. Because of these delays it is necessary to request extension of the project for an additional 12 months (until 07/31/2012) to complete the proposed research on short term and long term control strategies.
Impacts
The production of the F1, F2 and F3 generations of wPCN from Idaho has resulted in a more consistent production of cysts. This has resulted in an increased number of cysts (>29,000) for use in control and eradication studies by this project and other USDA-ARS projects associated with control and eradication of wPCN. More consistent hatching of the F1, F2 and F3 cysts has resulted in more reliable and successful experiments in both the greenhouse and laboratory. The isolation and identification of fungi and bacteria that have bio-control potential on wPCN will allow for deployment of these micro-organisms in Idaho fields to reduce the potential of hatching of wPCN cysts in the field. Since the microorganisms were collected from field derived cysts they would already be present in the Idaho potato production fields and would not require the introduction of a new or foreign organism into the fields. The results of the bio-fumigant study using B. juncea field meal could lead to the use of an organic method to fumigate potato fields to reduce the potential of hatching by wPCN. Since the seed meal is from a crop grown in Idaho and the Pacific Northwest there would be ready supply of the seed meal and would provide producers of the B. juncea with an additional market for their crop. The fumigant efficacy research has identified potential alternative soil fumigants for the control of wPCN other than Methyl Bromide. This will allow for the potential for the use of a soil fumigant to reduce wPCN viability even if Methyl Bromide is no longer available. Screening of potato genotypes from the USDA-ARS breeding programs could lead to the development of resistant potato genotypes which would be the ultimate long term control strategy for wPCN. Facilitating research on trap crops, alternative hosts and diffusates with USDA-ARS research programs has produced information on which weed species can produce wPCN and identification of the diffusate factor that can be used to potentially induce hatch when no suitable host is available, reducing the threat of wPCN in Idaho potato fields. Research on viability testing in this project has resulted in the addition of hatching studies to determine the effectiveness of repeated field fumigation to eradicate wPCN from Idaho potato fields.
Publications
- Boydston, R.A., Hojtahedi, H., Bates, C., Zemetra, R., and Brown, C.R. 2010. Weed hosts of Globodera pallida from Idaho. Plant Disease 94:918.
- Gao, X., Price, W.J., Worapong, J., King, E., Johnson, J.B., and Zemetra, R.S. 2010. The effect of mustard seed meal on viability of Globodera pallida. Society of Nematologists Meeting abstracts pg. 57.
- Worapong, J., Bates, C., Gao, X., Meacham, T.E., Johnson, J.B., and Zemetra, R.S. 2010. Screening of microorganisms associated with cysts of Globodera pallida isolated from southern Idaho fields. Society of Nematologoists Meeting abstracts pg. 120-121.
- X. Gao, King, B., Worapong, J., Johnson, J.B., and Zemetra, R.S. 2011. Hatching patterns of field and greenhouse populations of Globodera pallida from Idaho, USA. International Journal of Nematology. 21(1):1-6.
- Gao, X., Price, W.J., Bates, C., VanSickle, M.J., Worapong, J., Johnson, J.B., and Zemetra, R.S. 2011. Mustard seed meal reduces viability and hatching of Globodera pallida. Society of Nematologists Meeting abstracts pg. 85-86.
- Worapong, J., Johnson, T., Gao, X., Kuhl, J.C., Bates, C., Johnson, J.B., and Zemetra, R.S. 2011. Identification of five fungal species isolated from non-viable eggs of a sing Globodera pallida cyst based on a polyphasic approach. Society of Nematologists Meeting abstracts pg. 169-170.
- Gao, X., Worapong, J., Johnson, J.B., and Zemetra, R.S. 2011. Improving reproduction of the Idaho population of the pale cyst nematode, Globodera pallida, for use in studies to control and/or eradicate PCN in Idaho. American Phytopathological Society abstracts
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