Research project reports on nematode pests of potatoes

Biology of potato cyst nematodes (PCN)

 11120020 PhD: Characterisation of potato cyst nematode populations in Great Britain for sustainable crop management (2013-2018)

• national survey of the occurrence of the two PCN species in GB and the G. pallida pathotypes present
• comparison of lab-based methods to test PCN viability

 R433 PhD: Population dynamics of potato cyst nematodes in relation to temperature (2010-2013)

• rate and amount of PCN hatching according to temperature
• monitoring of field trials to understand if a second generation of PCN occurs in GB

 Sampling soils for PCN

1100006 Proficiency testing of potato cyst nematode (PCN) soil testing laboratories (2015-2016)

• proficiency of seven GB laboratories to assess the level of soil infestation by potato cyst nematode

11120017 Fellowship: Development of a Succession Potato Nematologist (2015-2018)

• soil sampling for PCN
• lab proficiency testing
• the PCN problem in Scotland and grower interviews about their approaches to PCN management

 R287 Validation of quantitative DNA detection systems for PCN (2006-2008)

• DNA-based diagnostics for testing soil for PCN, without the need to extract cysts from soil

Potato varieties and the management of PCN 

An educational tool (PCN calculator) was developed to demonstrate how PCN populations change with factors such as the variety grown, soil type and whether nematicides are used. It requires information on variety tolerance and resistance to PCN.  Projects were undertaken to generate tolerance data.

   R464 Assessment of variety tolerance to potato cyst nematode damage (2005-2006)

• tolerance of 10 potato varieties based on small plot trials

 R432 Assessment of variety tolerance to potato cyst nematode damage (2010-2012)

• tolerance of 12 potato varieties based on small plot trials

 11120026 Assessment of variety tolerance to potato cyst nematode damage (2015-2018)

• 1 tonne boxes, with and without introduced PCN inoculum, were used to test if the system would generate consistent information on variety tolerance

 11120019 PhD: Identification of avirulence genes in potato cyst nematode (PCN) as tools for assessing durability of resistance (2015-2018)

• molecular techniques were used to assess the likelihood that variety resistance to G. pallida will breakdown
• combining a range of different resistance sources in a single variety will be the most durable approach

11120021 PhD: Pyramiding resistances to potato cyst nematodes (PCN) to produce potato cultivars with durable and broad-spectrum resistance (2014-2018)

• studied the genetic basis of H2 resistance
• H2 provides resistance against G. pallida pathotype Pa1 whilst also conferring a lower level of control of pathotypes Pa2/3
• location of the H2 gene mapped to potato chromosome 5
• preliminary breeding combining resistance to G. rostochiensis (H1), G. pallida (H3) and H2 produced plants that were highly resistant to both species of PCN

Other management options

R468 PCN trap crops (2013-2016)

• pot-based evaluation of Solanum species as trap crops for PCN
• information on their optimum seed rates and herbicide sensitivity

  114R476 Biofumigation for PCN control (2014-2019)

• field evaluation of biofumigants for PCN management
• comparison of incorporation techniques
• impact of nitrogen and sulphur rates on biofumigant biomass and PCN numbers post-incorporation.

 CP 129 Establishing biofumigation as a sustainable replacement for pesticides (2014-2019)

• seedling density and isothiocyanate-release 
• rate of loss of biofumigant compound(s) after incorporation
• toxicity of volatile halide compounds to potato cyst nematode (PCN) juveniles
• sensitivity of Rhizoctonia solani and Verticillium dahliae to isothiocyanates
• decline in viability of PCN during growth of a brown mustard crop and after its incorporation 
• biofumigation and free-living nematodes 

 R254 Development of drip irrigation as a delivery system for the improved targeting and control of nematode pests in potatoes (2004-2007)

• hatching profiles for PCN cysts
• efficacy of oxamyl applied as a granule or as a liquid via drip irrigation systems

R269 Managing the decline of potato cyst nematodes (PCN): maximising natural decline and population suppression (2006 - 2009)

• factors that affect PCN decline rates between potato crops
• techniques for measuring decline rates
• fungal parasites of PCN and their sensitivity to fungicides
• lab studies of PCN hatch in the presence of Solanum sisymbriifolium
• effects of granular nematicides or fungal pathogens on PCN multiplication

Management of free-living plant parasitic nematodes (FLN)

R440 Free living nematodes – risks for potatoes (2011-2015)

• DNA-based detection of Longidorus, Paratrichodorus and Trichodorus species
• sampling guidelines for testing soil for FLN and tobacco rattle virus (TRV)
• impact of (Para)Trichodorus direct feeding damage on yield and processing quality
• testing alternative control options
• identifying molecular markers to facilitate the breeding of new potato varieties with resistance to TRV 

R255 Improvement of a diagnostic test to allow more precise localisation of Tobacco Rattle Virus in fields (2004-2006)

• molecular diagnostics used to map the occurrence of TRV in the roots of weeds in fields prior to potato cropping

R276 Research review on free-living nematodes & TRV spraing (2006)

• distribution of free-living nematodes and TRV
• effects of TRV on potatoes

11120009 PhD: Assessing the impact of root lesion nematode infestations on the production of potatoes (2016-2020)

• sampling potato fields for presence of root lesion nematodes
• improved molecular diagnostics for detection of Pratylenchus species
• Impact of penetrans on potato yield

Root-knot nematodes

11120024 A literature review of the root-knot nematodes (Meloidogyne species) that pose a threat to potato production in GB (2019)

• information on species of concern, their host ranges, identification and control.