title: Bioavailability of diuron, imazapic and isoxaflutole in soils of contrasting textures.
abstract: This research was aimed at understanding the dynamics of the herbicides diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], imazapic [2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-5-methylnicotinic acid] and isoxaflutole [5-cyclopropyl-4-(2-methanesulfonyl-4-trifluoromethyl benzoyl)isoxazole] in two soils of different physico-chemical properties. To accomplish such intent, several greenhouse experiments were run. The bioavailability of diuron (0; 1.6 and 3.2 kg ha(-1)), imazapic (0; 98 and 122.5 g ha(-1)) and isoxaflutole (0; 35 and 70 g ha(-1)) was measured in samples from a sandy loam soil and a clay soil, by sowing a bioindicator (Brachiaria decumbens), at 0, 25, 50, 75 and 100 days after herbicides application (DAA). Diuron was very stable in clay soil, providing control equal to or higher than 92% of bioindicator, up to 100 DAA, as assumed by biomass accumulation. No differential effect was observed in sandy loam soil, even when 2x labeled rate were applied. Imazapic provided a short bioavailability in relation to B. decumbens, independent of rates applied. The persistence of isoxaflutole was longer in clay soil (28 to 30 days).
authors.affiliation: Department of Agronomy, State University of Mato Grosso, Tangará da Serra, Brazil.
authors.forename: Miriam H
authors.initials: MH
authors.lastname: Inoue
authors.forename: Rubem S
authors.initials: RS
authors.lastname: Oliveira
authors.forename: Jamil
authors.initials: J
authors.lastname: Constantin
authors.forename: Diego G
authors.initials: DG
authors.lastname: Alonso
authors.forename: Cássio A
authors.initials: CA
authors.lastname: Tormena
mesh_terms: D001673:Biodegradation, Environmental; D001682:Biological Availability; D018533:Biomass; D004237:Diuron / Q000737:chemistry / Q000378:metabolism*; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism*; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism*; D007220:Industrial Waste; D007555:Isoxazoles / Q000737:chemistry / Q000378:metabolism*; D009539:Nicotinic Acids / Q000737:chemistry / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors
chemical_list: D006540:Herbicides; D007093:Imidazoles; D007220:Industrial Waste; D007555:Isoxazoles; D009539:Nicotinic Acids; D012987:Soil; D012989:Soil Pollutants; C415327:isoxaflutole; D004237:Diuron; C481028:imazapic