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dc.contributor.supervisor Tenuta, Mario (Soil Science) Daayf, Fouad (Plant Science) en
dc.contributor.author Mahran, Amro
dc.date.accessioned 2009-06-22T15:32:08Z
dc.date.available 2009-06-22T15:32:08Z
dc.date.issued 2009-06-22T15:32:08Z
dc.identifier.uri http://hdl.handle.net/1993/3157
dc.description.abstract Root-lesion nematodes, Pratylenchus spp., are serious pathogens of potato plants worldwide. Several management practices can control Pratylenchus spp.; however, they all have shown some limitations. Therefore, environmentally-safe, low-cost, and effective control strategies are needed as possible alternative to currently used strategies. This thesis was designed to assess if liquid hog manure (LHM) holds such potential. The objectives of this thesis were to determine: (i) the prevalence and identity of species of Pratylenchus spp. in Manitoba potato fields, (ii) if short-chain volatile fatty acids (VFA) in LHM are the constituents responsible for the manure’s toxicity to Pratylenchus spp. using solution exposure experiments (iii) the effectiveness of LHM in killing Pratylenchus spp. in soil, and (iv) the impact of LHM on nematode communities. Pratylenchus spp. were detected in 39% of 31 potato fields surveyed in Manitoba with population densities ranging, for positive fields, from 45 to 631 nematodes kg-1 fresh soil. Morphometrics of female nematodes and molecular diagnosis (using species-specific PCR primers) showed that the species of Pratylenchus present in the potato fields to be P. neglectus. Potato, cv. Russet Burbank, showed to be a poor host to two populations of Pratylenchus spp. from Manitoba potato fields. Accordingly, P. neglectus does not seem to be a limitation to potato production in Manitoba; thus, P. penetrans, the most widely spread and damaging species to potato was used in the successive studies of assessing the use of LHM to control Pratylenchus spp. in potato fields. VFA (acetic, propionic, n-butyric, isobutyric, n-valeric, isovaleric, and n-caproic acids) accounted for the majority of the lethal effect of LHM to P. penetrans under acidic conditions. VFA in LHM killed Pratylenchus spp. in soil and acidification seemed to enhance its ability when VFA concentration in the manure is low. LHM did not act as a soil fumigant eliminating soil trophic interactions but increased bottom-up food web interactions. VFA in LHM persisted in the soil for four days with biological degradation being their mode of loss. In conclusion, LHM is potentially an effective and low-cost strategy to control Pratylenchus spp. and its efficacy can be improved by acidification. en
dc.format.extent 1598340 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject Nematode en
dc.subject Pratylenchus en
dc.subject Liquid Hog Manure en
dc.subject Biological Control en
dc.subject Volatile Fatty Acids en
dc.subject Identification en
dc.subject Soil Health en
dc.subject Communities Analysis en
dc.subject Polymerase Chain Reaction en
dc.subject Soil en
dc.title Suppression of the root-lesion nematode using liquid hog manure en
dc.degree.discipline Plant Science en
dc.contributor.examiningcommittee Hanson, Mark (Environment & Geography)Fernando, Dilantha (Plant Science) Chen, Senyu (University of Minnesota) en
dc.degree.level Doctor of Philosophy (Ph.D.) en
dc.description.note October 2009 en


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