Prevalence and diversity of plant parasitic nematodes in Northern Ireland grassland and cereals, and the influence of soils and rainfall

Abstract

The prevalence and diversity of plant parasitic nematodes in Northern Ireland cereal and grassland was determined from 191 agricultural fields. A total of 18 nematode genera were detected, including economically important pests, Meloidogyne spp., Heterodera spp. and Pratylenchus spp., each of which were above economic damage thresholds in a significant proportion of the sites (92.4%, 70% and 28.6%, respectively). The detection of the root knot nematode, Meloidogyne minor (6% prevalence), was significant given its recent emergence across the turf grass sector and the prospect of M. minor becoming a common agricultural pest. Analyses of nematode prevalence and abundance highlighted significant associations with grass and cereals, soil types, soil grade (proxy for soil quality) and rainfall levels. Specifically, nematode populations varied between the two major soils (brown earths and gleys), while significant trends for increased nematode diversity and greater prevalence of both Meloidogyne and Pratylenchus with increasing rainfall were also observed. Multivariate analyses were performed to determine interactive effects and the relative importance of the factors affecting nematode populations. Notably, rainfall, in combination with either crop type or soil grade, had a significant effect on nematode abundance and diversity. The findings suggest significant changes in nematode populations have occurred over the last several decades and the possibility that these are linked to changing climate and cropping practices are discussed, as well as future concerns for plant parasitic nematode management.

Quantifying the economic cost of invertebrate pests to New Zealand’s pastoral industry

“…Of the damaging species present in this country which have been recorded (or observed) from pasture or forage crops there are four species each of Meloidogyne (M. trifoliophila, M. hapla, M. fallax and M. naasi); Heterodera (H. trifolii, H. aucklandica, H. avenae and H. schachtii) and Pratylenchus (P. penetrans, P. crenatus, P. neglectus and P. thornei) (Knight et al 1997;Mercer et al 1997, L. Waeyenberge, pers comm., pers obs). In addition, a recent incursion of M. minor into New Zealand (Zhao et al 2017) represents a species which, while mostly a pest of turf (Entwistle et al 2014), has become established in pasture situations overseas (Fleming et al 2016).…”

Aanwezigheid en dichtheden van plantparasitaire nematoden in Nederlands productiegrasland

“…Bij de Heteroderidae geeft het ontbreken van cystenonderzoek een onderschatting van de werkelijke dichtheden. Het ontbreken van cystenonderzoek kan ook de reden zijn dat het geslacht Punctodera niet werd aangetroffen (Fleming et al 2016). Om de dichtheid van de familie Trichodoridae betrouwbaar vast te stellen, moet er tenminste tot 30 cm diep bemonsterd worden (in plaats van tot 10 cm), aangezien deze nematoden zich over de diepte van de bouwvoor kunnen verplaatsen.…”

“…Bovenstaande gegevens duiden op een mogelijke verschuiving in de soortsamenstelling over de afgelopen decennia. Fleming et al (2016) suggereerden een dergelijke verschuiving voor Noord-Ierland, waarbij deze verschuiving (ook) gelinkt werd aan veranderingen in gewasmanagement.…”

Parallel Microbial Ecology of Pasteuria and Nematode Species in Scottish Soils

“…with exact matches to both M. chitwoodi and M. fallax with 99.7% identity to M. minor has a read abundance μl −1 ≥ 1 in 9.2% of successfully amplified ESFN samples. Fleming et al (2016) recently surveyed cereal and grassland soils in Northern Ireland, finding that M. minor was prevalent in 6% of soils tested. The abundance of this ZOTU is, however, typically low.…”