Treated wastewater as irrigation source: a microbiological and chemical evaluation in apple and nectarine trees

摘要: Abstract The use of secondary treated wastewater (STW) for irrigation is considered as a strategy to mitigate water shortage in summer periods. Unfortunately, the utilization STW agriculture not exempt from environmental and health risks, being potential source toxic chemicals (e.g. heavy metals) human pathogens Salmonella spp. Escherichia coli). aim this work verify whether apple nectarine trees with may lead metal microbial contamination shoot, leaf fruit tissues. Three-year old were grown pots drip irrigated separately, one season, using either tap (TW) or STW. did affect trace element concentration B, Na, Zn) both leaves fruits. Heavy concentrations tissues lower than international limits consumption species. Independently species, total bacterial count (TBC) on shoot was almost double plants compared TW-irrigated ones. No E. coli found fruit; few coliforms (TC) detected fruits, far below European microbiological foodstuff. Finally, laboratory trial, aimed at evaluating possible mechanisms translocation inside plants, carried out 3-month peach rootstock (i.e. GF 677), artificially inoculated two strains, characterized by different level pathogenicity (disarmed DH5α 1576). Populations strains isolated epiphytic endophytic only root level. Nonetheless, population 1576 generally higher strain. Colonization epigeal part never observed. These results are promising STW, especially orchards, since does wet canopy consequently final product.