title: Imazethapyr and imazapic, bispyribac-sodium and penoxsulam: zooplankton and dissipation in subtropical rice paddy water.
abstract: Herbicides are very effective at eliminating weed and are largely used in rice paddy around the world, playing a fundamental role in maximizing yield. Therefore, considering the flooded environment of rice paddies, it is necessary to understand the side effects on non-target species. Field experiment studies were carried out during two rice growing seasons in order to address how the commonly-used herbicides imazethapyr and imazapic, bispyribac-sodium and penoxsulam, used at recommended dosage, affect water quality and the non-target zooplankton community using outdoor rice field microcosm set-up. The shortest (4.9 days) and longest (12.2 days) herbicide half-life mean, estimated of the dissipation rate (k) is shown for imazethapyr and bispyribac-sodium, respectively. Some water quality parameters (pH, conductivity, hardness, BOD5, boron, potassium, magnesium, phosphorus and chlorides) achieved slightly higher values at the herbicide treatment. Zooplankton community usually quickly recovered from the tested herbicide impact. Generally, herbicides led to an increase of cladocera, copepods and nauplius population, while rotifer population decreased, with recovery at the end of the experiment (88 days after herbicide treatment).
authors: Department of Plant Protection, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil. Electronic address: geovane_reimche@yahoo.com.br.
authors: Geovane B
authors: GB
authors: Reimche
authors: Department of Plant Protection, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil.
authors: Sérgio L O
authors: SL
authors: Machado
authors: Department of Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors: Maria Angélica
authors: MA
authors: Oliveira
authors: Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors: Renato
authors: R
authors: Zanella
authors: Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors: Valderi Luiz
authors: VL
authors: Dressler
authors: Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors: Erico M M
authors: EM
authors: Flores
authors: School of Chemistry and Food, Federal Foundation University of Rio Grande (FURG), 95500-000 Santo Antônio da Patrulha, RS, Brazil.
authors: Fábio F
authors: FF
authors: Gonçalves
authors: Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors: Filipe F
authors: FF
authors: Donato
authors: Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors: Matheus A G
authors: MA
authors: Nunes
mesh_terms: D000383:Agriculture; D000818:Animals; D001565:Benzoates / Q000032:analysis / Q000378:metabolism; D001673:Biodegradation, Environmental; D006540:Herbicides / Q000032:analysis / Q000378:metabolism*; D007093:Imidazoles / Q000032:analysis / Q000378:metabolism; D009539:Nicotinic Acids / Q000032:analysis / Q000378:metabolism; D012275:Oryza; D011743:Pyrimidines / Q000032:analysis / Q000378:metabolism; D013449:Sulfonamides / Q000032:analysis / Q000378:metabolism; D014529:Uridine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D015048:Zooplankton / Q000502:physiology*
chemical_list: D001565:Benzoates; D006540:Herbicides; D007093:Imidazoles; D009539:Nicotinic Acids; D011743:Pyrimidines; D013449:Sulfonamides; D014874:Water Pollutants, Chemical; C093630:imazethapyr; C504402:penoxsulam; C549011:bispyribac; C481028:imazapic; D014529:Uridine
keywords: Aquatic ecosystem; Crustacean; Freshwater; Herbicides; Rotifers; Water quality