Several perennial and annual crops in the northern coast of Peru significantly reduce their productivity due to the damage caused by root-knot nematodes (RKN, Meloidogyne spp.). Routine nematode analyses carried out on these crops detected the presence of Pasteuria penetrans (Thorne) Sayre and Starr endospores attached to second stage juveniles (J2) of RKN. Soil sampling was carried out in different valleys to determine the prevalence and the number of attached endospores of P. penentrans. We also compared whether the differences between population fluctuations of Meloidogyne incognita (Kofoid and White) Chitwood in soils infested and not by P. penetrans were linked to a potential suppressive effect. 17.8% of soil samples collected from grapevine, pepper and banana plants in the valleys of Medio Piura, Bajo Piura, Alto Piura, Chira, San Lorenzo and Olmos showed presence of P. penetrans. No endopores were found in samples from crops such as sugar cane and asparagus. An average of 30.5 endospores per nematode was estimated. The J2 populations found in grapevine cultivated soils not infested with P. penetrans were 1.7 to 2.3 times higher than in soils infested by P. penetrans. The percentages of J2 with endospores were correlated (rho = 0.35; P < 0.02) with the abundance of M. incognita populations. These results confirm the widespread occurrence of P. penetrans in the crops and valleys sampled and its biological potential as a natural suppressor of Meloidogyne spp. populations in the northern coast of Peru. Further long-term surveys are needed to confirm the impact of P. penetrans on nematode regulation and collect isolates for taxonomic, molecular and host-specificity studies.

Copper (Cu) toxicity is a pressing concern for several soils, especially in organic viticulture. The objective of this work was to assess Cu toxicity on the non-target organism Eisenia fetida, employing both traditional and novel tools for early identification of Cu-induced damages. In addition to traditional tests like avoidance and reproductive toxicity experiments, other tests such as the single cell gel electrophoresis (SCGE) and gut microbiome analysis were evaluated to identify early and more sensitive pollution biomarkers. Four sub-lethal Cu concentrations were studied, and the results showed strong dose-dependent responses by the earthworm avoidance test and the exceeding of habitat threshold limit at the higher Cu doses. An inverse proportionality was observed between reproductive output and soil Cu concentration. Bioaccumulation was not detected in earthworms; soil concentrations of potentially bioavailable Cu were not affected by E. fetida presence or by time. On the contrary, the SCGE test revealed dose-dependent genotoxicity for the 'tail length' parameter already at the second day of Cu exposition. Gut microbiome analysis a modulation of microbial composition, with the most aboundant families being Pectobateriaceae, Comamonadaceae and Microscillaceae. Bacillaceae increased over time and showed adaptability to copper up to 165 mg/kg, while at the highest dose even the sensitive Acetobacteriaceae family was affected. The research provided new insights into the ecotoxicity of Cu sub-lethal doses highlighting both alterations at earthworms' cellular level and changes in their gut microbiota.

In the Mediterranean area, vineyard soils are often characterized by a high stone content. In these contexts, where tools commonly adopted for under-row weed control are frequently damaged, the utilization of a chain mower could be a preferable alternative. This research aims to compare a modified mower with chains with other tools commonly employed that control weeds through tillage, such as motorized discs, blade weeder, and rotary star hoe. Weed control effectiveness, effects on weed flora composition, soil compaction, and operative efficiencies were evaluated. The chain mower allowed us to obtain encouraging results of weed biomass reduction (55.4 and 25.4%, between and around vine trunks, respectively), weed height reduction (35.9%), and weed cover reduction (79.2%), comparable to the other tools. All the tools showed a lower weed control efficacy around vine trunks rather than between them (weed biomass reductions of 24.8% and 52.6%, respectively). Results regarding the effect on weed flora composition seem to confirm this trend. Despite the higher chain mower field time (3.78 h ha-1) and fuel consumption (24.24 kg ha-1) compared to the blade weeder and the rotary star hoe, its versatility in stony soil and its lower impact on soil (soil penetration resistances of 1602.42 and 2262.83 kPa in 2022 and 2023, respectively) compared to the other tools make it a potentially advantageous implement for under-row weed management in vineyards. Further studies could be useful to improve chain mower performance, particularly around vine trunks, by evaluating in different planting layouts different dimensions of both the cutting element and feeler, which allows the vine-skipping mechanism.