Impact of agricultural practices and environmental variables on plant-parasitic nematode communities in fields at a landscape scale

Abstract

Agricultural practices shaping plant-parasitic nematode (PPN) assembly are still unclear, and this limits our understanding of the impact of anthropic disturbances on the resilience of PPN communities and the emergence of agronomic problems. Here the abundance and diversity of PPN in France’s oilseed rape production area was determined by sampling 72 fields over two consecutive years. We identified and counted PPN taxa and collected anthropic and environmental variables for the past 5 years. PPN were assigned to seven genera and one family including PPN that have not been identified to genus level. Using multiple correspondence analyses, we selected the main variables and tested their effect on the abundance of each taxon with mixed generalised linear models. We emphasise that at the landscape scale investigated, crop rotations were no longer a major factor impacting the PPN communities. However, we observed that tillage and pesticides had a significant impact on several taxa.

Diversity of plant parasitic nematodes characterized from fields of the French national monitoring programme for the Columbia root-knot nematode

“…The extraction protocol was the same as in Garcia et al . [ 21 ]. Briefly, mobile stages were extracted from 300 mL of fresh soil according to EPPO protocol for nematode extraction [ 52 ], using an Oostenbrink elutriator (Meku, Germany).…”

“…The effects of the variables on the abundance variation of each PPN taxon were evaluated, using a statistical strategy similar to that described by Garcia et al . [ 21 ]. Briefly, we first used Multiple Correspondence Analysis (MCA) using the “FactoMineR” R-package [ 61 ] to describe our dataset and to select the main contributing variables without any a priori knowledge [ 62 , 63 ].…”

“…: profound tillage, soil texture, or heavy metal content) [ 11 , 14 , 15 ]. There are, to our knowledge, only a few studies dealing with a larger number of variables and/or at broad spatial scales [ 20 , 21 ]. In the present study, we sampled fields that are part of the French monitoring programme for M .…”

“…However, studies often focus on a few environmental conditions or crop practices at the same time (e. g.: profound tillage, soil texture, or heavy metal content) [11,14,15]. There are, to our knowledge, only a few studies dealing with a larger number of variables and/or at broad spatial scales [20,21]. In the present study, we sampled fields that are part of the French monitoring programme for M. chitwoodi in several geographical areas in order to (i) describe the diversity and abundance of PPN communities in fields including a root crop in the crop rotation, (ii) evaluate whether cultivation practices identified in the literature at smaller scales in fact shape PPN communities at larger scale and (iii) assess the potential impact of environmental variables on PPN communities, including climate and physico-chemical conditions of soil.…”

Evidence of strong gene flow among French populations of the carrot cyst nematode Heterodera carotae

“…Twenty‐two populations were collected at the field scale: two fields in the Mont St‐Michel area, five fields in the Val‐de‐Saire area and 15 in the Créances area. Following the method of Garcia et al (), 10 sample points were defined along the longest diagonal of each field. Samples from each point were taken at a depth of 15 cm using a manual auger (diameter 2.5 cm) and pooled, resulting in one sample per field.…”