title: Copper release from chemical root-control baskets in hardwood tree production.
abstract: The City of Montreal, Canada, evaluated the environmental impact and usefulness of in-ground copper (Cu)-treated baskets in controlling root growth of hardwood trees in nursery culture. Using baskets planted with 5-yr-old Norway maple (Acer platanoides L.) trees, the amount and temporal pattern of Cu release from the basket surface into soil was determined for two copper formulations: Cu metal powder and Cu(OH)2. Release of both Cu formulations from the basket surface decreased exponentially over time, with Cu concentration at the basket surface dropping to 2% of the initial Cu applied by the end of the second field season. Total Cu content increased significantly in the soil around the baskets (from 7 to 28 mg Cu kg(-1) soil) and in the baskets (from 7 to 50-70 mg Cu kg(-1) soil) over the two years of the study. Three levels of phosphorus application (33, 66, and 100% of the regular nursery rate of 465 kg ha(-1) yr(-1)) did not affect release of Cu from the basket surface. The release of Cu metal at 28 and 105 d in the field was significantly increased by inoculation with the symbiotic arbuscular mycorrhizal fungus (AMF) Glomus intraradices Schenck & Smith; however, AMF inoculation had no affect on Cu(OH)2 release. Trees grown in Cu-treated baskets and inoculated with G. intraradices had similar colonization to non-inoculated trees, suggesting that inoculation was not very effective and that AMF inoculum was already present in the root ball of the trees at planting. After two years, copper basket-grown trees had significantly less root colonization than isolated control trees growing in the open field. This strongly suggests that conditions inside the baskets were not favorable to AMF.
authors.affiliation: Dep. of Natural Resource Sciences, McGill Univ., Ste-Anne-de-Bellevue, QC, Canada.
authors.forename: Sonja
authors.initials: S
authors.lastname: Kosuta
authors.forename: Chantal
authors.initials: C
authors.lastname: Hamel
authors.forename: Yolande
authors.initials: Y
authors.lastname: Dalpé
authors.forename: Marc
authors.initials: M
authors.lastname: St-Arnaud
mesh_terms: D031002:Acer / Q000187:drug effects* / Q000254:growth & development; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D005308:Fertilizers; D016468:Forestry / Q000379:methods; D006801:Humans; D006878:Hydroxides / Q000737:chemistry / Q000494:pharmacology*; D038821:Mycorrhizae; D010758:Phosphorus; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D012987:Soil / Q000032:analysis*
chemical_list: D005308:Fertilizers; D006878:Hydroxides; D012987:Soil; D010758:Phosphorus; C001606:cupric hydroxide; D003300:Copper