Progress 10/01/04 to 09/30/09
Outputs
OUTPUTS: A large farming systems trial, begun in 1999 to evaluate transition methods for conversion from conventional to organic farming practices, was continued through 2009. Common nematodes found include Pratylenchus crenatus, Xiphinema rivesi, Helicotylenchus spp., Tylenchorhynchus spp. Meloidogyne hapla, and Clarkus papillatus (predator). Population densities remained low for all plant parasites throughout the ten years of this experiment and few differences among compost treatments or crops were statistically significant. Increases over the growing season were not observed, suggesting the presence of suppressive soils. Bacterial feeding nematodes tended to increase over the trial, but differences among compost treatments were not significant at any date. The experiment will continue through 2012. Compost and fertility amendments were evaluated for their effect on potato growth and nematode reproduction. Four replicate plots of three potato cultivars were amended with 0, 20, or 40 tons per acre of dairy manure compost and side-dressed one month after planting with 0 or 500 pounds/acre of blood meal (0 or 60 lb N/Acre). Soil samples were collected at planting, in mid-summer and at harvest, and yields were analyzed. Statistically significant differences in yield were found among fertility treatments, with the greatest response to fertility in the cultivar Keuka Gold, and the least response in All Blue. Nematode populations densities remained low, and did not differ among cultivars or fertility treatments. Grazing management practices were evaluated for control of intestinal parasites of sheep in organic farming systems. Rotational grazing, with or without supplemental protein nutrition and the use of creep gates for lambs are being evaluated. Intestinal parasite population densities were determined from fecal egg counts, and the health of lambs was assessed using FAMACHA scores, live weights, and whether synthetic antihelmintics were required. Lambs from ewes that received protein supplements before lambing were less likely to require antihelmintic treatment than those from ewes without protein supplementation (P < 0.05). However, lambs in flocks that were creep grazed, were slightly more likely to require antihelmintics (P < 0.10). Another experiment was conducted to evaluate the efficacy of the nematode trapping fungus, Arthrbotrys oligospora, against Meloidogyne incognita. Nematode mortality rates in soil inoculated with trapping fungi were greater than in those beakers without fungi (P<0.10), suggesting that Arthrobotrys oligospora provided low levels of control of M. incognita. The incidence of Pasteuria penetrans on Pratylenchus penetrans was determined by extracting lesion nematodes from soils from 23 organic growers and examining the nematodes for presence of attached spores. Lesion nematodes with attached spores were observed in 7 of 36 fields. An experiment to assess suppressiveness of Pasteuria to lesion nematode found that nematode populations were about 30 % lower in soils with Pasteuria than in soils without, but differences were not statistically significant. PARTICIPANTS: The Principle Investigator at West Virginia University is James Kotcon, Associate Professor of Plant Pathology. This Multi-state project involved collaboration with nematologists from Connecticut, Massachusetts, New York, Pennsylvania, Rhode island, Maryland, Florida, Georgia, Alabama, South Carolina, and Michigan, as well as USDA collaborators. Training and Professional Development included annual meetings of the Regional Nematology Research Technical Committee, as well as ongoinig training for three graduate students, and several undergraduate interns. TARGET AUDIENCES: Target audiences included farmers, gardeners, field crop advisors, Extension agents, scientists, consumers, and agency personnel. Frequent nematode diagnostic services and recommendations for nematode management provided asistance to growers and crop advisors. Presentations were also held at national research meetings. Results were translated into Extension publications advising growers and the general public. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Use of chemical nematicides has been restricted, requiring alternative nematode management practices. Use of crop rotation and organic amendments could reduce nematode populations. These studies demonstrate that two organic farming systems have suppressed plant-parasitic nematodes, although the mechanisms remain undetermined. A better understanding of nematode behavior and nematode population dynamics is needed to improve soil management. The impact of organic management practices on crop production represents an approach that can identify improved nematode management for both conventional and organic producers. While biological control agents, such as predatory nematodes, trapping fungi or the bacterium Pasteuria penetrans, are common in agricultural soils, limited success has been achieved in using these agents. More needs to be learned about their biology in order to obtain consistent control of plant-parasitic nematodes common in agriculture.
Publications
- Panaccione, D. G., J. B. Kotcon, C. Schardl, R. Johnson, and J. Morton. 2006. Ergot alkaloids are not essential for endophytic fungus-associated population suppression of the lesion ematode, Pratylenchus scribneri, on perennial ryegrass. Nematology 8:583-590.
- Salinas, K., S. Edenborn, A. Sexstone, and J. B. Kotcon. 2007. Bacterial preferences of the bacterivorous soil nematode Cephalobus brevicauda (Cephalobidae): effect of bacterial type and size. Pedobiologia 51:55-64.
- Salinas, K., Kotcon, J., 2006. Effects of Kodiak (Bacillus subtilis strain GBO3) on Soil-Inhabiting Nematodes near the Rhizosphere of Treated vs. Untreated Snap Bean Seeds In Situ. J. Sustainable Agr. 39:5-12.
- Salinas, K. A., and J. Kotcon. 2005. In vitro culturing of the predatory soil nematode Clarkus papillatus. Nematology 7(1):5-9.
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Progress 01/01/07 to 12/31/07
Outputs
A large farming systems trial, begun in 1999 to evaluate transition methods for conversion from conventional to organic farming practices, was continued through 2006. Common nematodes found include Pratylenchus crenatus, Xiphinema rivesi, Helicotylenchus spp., Tylenchorhynchus spp. Meloidogyne hapla, and Clarkus papillatus (predator). Population densities remained low for all plant parasites throughout the seven years of this experiment and few differences among compost treatments or crops were statistically significant. Increases over the growing season were not observed, suggesting the presence of suppressive soils. Bacterial feeding nematodes tended to increase over the trial, but differences among compost treatments were not significant at any date. The experiment will continue through 2009. Compost and fertility amendments were evaluated for their effect on potato growth and nematode reproduction. Four replicate plots of three potato cultivars were amended with 0,
20, or 40 tons per acre of dairy manure compost and side-dressed one month after planting with 0 or 500 pounds/acre of blood meal (0 or 60 lb N/Acre). Soil samples were collected at planting, in mid-summer and at harvest, and yields were analyzed. Statistically significant differences in yield were found among fertility treatments, with the greatest response to fertility in the cultivar Keuka Gold, with the least response in All Blue. Nematode populations densities remained low, and did not differ among cultivars or fertility treatments. Grazing management practices were evaluated for control of intestinal parasites of sheep in organic farming systems. Rotational grazing, with or without supplemental protein nutrition and the use of creep gates for lambs are being evaluated. Intestinal parasite population densities were determined from fecal egg counts, and the health of lambs was assessed using FAMACHA scores, live weights, and whether synthetic antihelmintics were required. Lambs
from ewes that received protein supplements before lambing were less likely to require antihelmintic treatment than those from ewes without protein supplementation (P < 0.05). However, lambs in flocks that were creep grazed, were slightly more likely to require antihelmintics (P < 0.10). Another experiment was conducted to evaluate the efficacy of the nematode trapping fungus, Arthrbotrys oligospora, against Meloidogyne incognita. Nematode mortality rates in soil inoculated with trapping fungi was greater than in those beakers without fungi (P<0.10), suggesting that Arthrobotrys oligospora provided low levels of control of M. incognita. The incidence of Pasteuria penetrans on Pratylenchus penetrans was determined by extracting lesion nematodes from soils from six organic growers and examining the nematodes for presence of attached spores. Lesion nematode cultures on corn root explants were initiated, in an effort to develop cultures of Pasteuria on Pratylenchus. The goal is to compare
lesion nematode survival and Pasteuria reproduction in vivo and in sterile soil.
Impacts
Use of chemical nematicides has been restricted, requiring alternative nematode management practices. Use of crop rotation and organic amendments could reduce nematode populations. These studies demonstrate that two organic farming systems have suppressed plant-parasitic nematodes, although the mechanisms remain undetermined. A better understanding of nematode behavior and nematode population dynamics is needed to improve soil management. The impact of organic management practices on crop production represents an approach that can identify improved nematode management for both conventional and organic producers.
Publications
- Panaccione, D. G., J. B. Kotcon, C. Schardl, R. Johnson, and J. Morton. 2006. Ergot alkaloids are not essential for endophytic fungus-associated population suppression of the lesion ematode, Pratylenchus scribneri, on perennial ryegrass. Nematology 8:583-590.
- Salinas, K., S. Edenborn, A. Sexstone, and J. B. Kotcon. 2007. Bacterial preferences of the bacterivorous soil nematode Cephalobus brevicauda (Cephalobidae): effect of bacterial type and size. Pedobiologia 51:55-64.
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Progress 01/01/06 to 12/31/06
Outputs
A large farming systems trial, begun in 1999 to evaluate transition methods for conversion from conventional to organic farming practices, was continued through 2006. Common nematodes found include Pratylenchus crenatus, Xiphinema rivesi, Helicotylenchus spp., Tylenchorhynchus spp. Meloidogyne hapla, and Clarkus papillatus (predator). Population densities remained low for all plant parasites throughout the seven years of this experiment and few differences among compost treatments or crops were statistically significant. Increases over the growing season were not observed, suggesting the presence of suppressive soils. Bacterial feeding nematodes tended to increase over the four years of the trial, but differences among compost treatments were not significant at any date. The experiment will continue through 2009. Preference of a bacterial-feeding nematode, C. brevicauda, for various bacteria was evaluated in paired trials. C. brevicauda reproduction was greatest on a
soil bacterium, tentatively identified as Bacillus mycoides. Reproduction was low on E. coli, and lowest on a nematode-associated bacterium, related to Flexibacter sancti. C. brevicauda was attracted toward E. coli at significantly higher levels than toward B. thuringiensis, B. pumilus, three soil bacteria, and one nematode-associated bacterium. C. brevicauda tended to be attracted to bacteria with smaller cell size, and tended to prefer Gram negative to Gram positive bacteria. An experiment evaluated thyme oil preparations for root knot nematode management in greenhouse tomato beds. ProMax (3.5 % thyme oil) significantly reduced populations of Meloidogyne compared to untreated plots. However, population densities of lesion, spiral and dagger nematodes tended to be higher in treated plots. Results of Nematode Biocontrol Activity assays were inconclusive, as survival and infectivity of Meloidogyne incognita was significantly greater in sterilized thyme-treated soil than in non-treated
controls.
Impacts
Use of chemical nematicides has been restricted, requiring alternative nematode management practices. Use of crop rotation and organic amendments could reduce nematode populations. These studies demonstrate that two organic farming systems have suppressed plant-parasitic nematodes, although the mechanisms remain undetermined. Alternative products such as thyme oil may also reduce nematode damage, although the effect was relatively small in this study. A better understanding of nematode behavior and nematode population dynamics is needed to improve soil management.
Publications
- Salinas, K., Kotcon, J., 2006. Effects of Kodiak (Bacillus subtilis strain GBO3) on Soil-Inhabiting Nematodes near the Rhizosphere of Treated vs. Untreated Snap Bean Seeds In Situ. J. Sustainable Agr. In Press.
- Salinas, K. A., and J. Kotcon. 2005. In vitro culturing of the predatory soil nematode Clarkus papillatus. Nematology 7(1):5-9.
- Panaccione, D. G., J. B. Kotcon, C. Schardl, R. Johnson, and J. Morton. 2006. Ergot alkaloids are not essential for endophytic fungus-associated population suppression of the lesion nematode, Pratylenchus scribneri, on perennial ryegrass. Nematology 8:583-590.
- Salinas, K., S. Edenborn, A. Sexstone, and J. B. Kotcon. 2006. Feeding preferences of the bacterivorous soil nematode Cephalobus brevicauda (Cephalobidae): effect of bacterial type and size. Pedobiologia (in press).
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Progress 01/01/05 to 12/31/05
Outputs
A large farming systems trial, begun in 1999 to evaluate transition methods for conversion from conventional to organic farming practices, was continued through 2005. A vegetable crop trial and a field crop trial evaluated a high input, compost-intensive management system versus a low-input system that relies on green manures and cover crops. High input treatments received 10 tons/acre of composted dairy manure annually. Cover crops were planted and plowed in as green manures in low input plots. Soil samples were analyzed for plant-parasitic and predatory nematodes, and assayed for nematode biocontrol agent activity. Pratylenchus crenatus, Xiphinema rivesi, Helicotylenchus spp., Tylenchorhynchus spp. Meloidogyne hapla, and Clarkus papillatus (predator) were the most common nematodes present. Population densities remained low for all plant parasites throughout this experiment and differences among compost treatments or crops were not statistically significant,
suggesting the presence of suppressive soils. Predatory nematode population densities were also low, but were significantly higher in plots with compost than plots without. Bacterial feeding nematodes tended to increase over the four years of the trial, but compost treatments did not differ. Data analyses continued on experiments assessing nematode suppression by endophyte infected fescue and in trials to evaluate biocontrol potential of the predatory nematode, Clarkus papillatus.
Impacts
Alternative management systems for nematodes represent a high priority for horticultural and field crops because chemical nematicides have become less available due to regulatory restrictions. The use of biologically-based pest management tactics will be important in conventional and alternative cropping systems.
Publications
- Molinari, S., F. Lamberti, L. W. Duncan, J. Halbrendt, J. Kotcon, G. Abawi, R. Robbins, A. Nyczepir, M. McKenry, J. Magunacelaya, R. Crozzoli, R. Lemos, P. Nagy, M. Moens, and D. J. F. Brown. 2005. SOD polymorphism in Xiphinema americanum-group (Nematoda: Longidoridae). Nematology 6(6):867-876
- J. R. Hendricks and J. B. Kotcon. 2005. Nematode management in Malus domesticus using endophyte-infected fescue as ground cover. Journal of Nematology. (accepted for publication)
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