ABSTRACT
Com o objetivo de verificar o acúmulo de ácido chiquímico em plantas de laranja pêra (Citrus sinensis) num pomar comercial manejado com glifosato, um herbicida sistêmico de amplo espectro, foram coletadas amostras na Fazenda Jequitibá, tradicional no cultivo de citros, situada no Município de Santo Antônio de Posse, SP. O produtor aplicou de forma convencional Roundup® Original a 1.440 g.ha-1 de equivalente ácido (e.a.) do sal de isopropilamino de glifosato em 19/12/ 2006 na entrelinha de 15 plantas, deixando outras cinco como testemunha. A reaplicação de glifosato a 1.260 g.ha-1 de e.a. foi realizada em 2/4/2007. Em ambos os casos, imediatamente antes da aplicação e aos 3, 7, 10, 15, 20 e 35 dias após, foram coletadas 20 folhas de cada planta tanto da área tratada como da não tratada, analisando-se o teor de ácido chiquímico por cromatografia líquida de alta eficiência (CLAE) de forma isocrática após extração por micro-ondas. Os resultados mostraram não ocorrer acúmulo do ácido chiquímico nas plantas de laranja pêra, não havendo diferenças significativas nos teores deste composto entre o material proveniente da área tratada com glifosato e o daquela capinada manualmente.
In order to check the accumulation of shikimic acid in a traditional commercial grove of citrus "Pêra" cultivar (Citrus sinensis) managed for weed control with glyphosate, a systemic herbicide with wide spectrum, samples were collected at Fazenda Jequitibá, in Santo Antonio de Posse County, São Paulo State, Brazil. The producer applied the following treatments of Roundup Original® glyphosate at 1,440 g.ha-1 a.e. of the isopropylamine salt on 19 December 2006 between rows of 15 plants, leaving five others as control. The reapplication of glyphosate at 1,260 g ha-1 was done on 2 April 2007. In both cases, immediately before application and at 3, 7, 10, 15, 20 and 35 days thereafter, 20 leaves from each treated and untreated plants were collected for analysis of the content of shikimic acid by isocratic high performance liquid chromatography (HPLC) assisted with microwave. The results showed no significant differences in levels of shikimic acid between the material from the area treated with glyphosate and that weeded manually.
Subject(s)
Shikimic Acid/analysis , Citrus/parasitology , Herbicides , Chromatography, High Pressure LiquidSubject(s)
Agriculture/methods , Herbicides/analysis , Soil Pollutants/analysis , Water Movements , Arachis , Atrazine/analysis , Brazil , Porosity , Saccharum , Simazine/analysis , Triazines/analysisSubject(s)
Atrazine/analysis , Atrazine/metabolism , Herbicides/analysis , Herbicides/metabolism , Soil Pollutants/analysis , Soil Pollutants/metabolism , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/metabolism , Water Supply , Agriculture , Biodegradation, Environmental , Brazil , Environmental MonitoringABSTRACT
A simple, rapid and quantitative bioassay method was compared to a gas chromatography/mass spectrometry (GC/MS) procedure for the analysis of ametryn in surface and groundwater. This method was based on the activity of ametryn in inhibiting the growth of the primary root and shoot of germinating letuce, Lactuca sativa L. seed. The procedure was sensitive to 0.01 microgram/l and was applicable from this concentration up to 0.6 microgram/l. Initial surface sterilization of the seed, selection of pregerminated seed of certain root lengths and special equipment are not necessary. So, we concluded that the sensitivity of the bioassay method is compatible with the chromatographic method (GC-MS). However, the study of the correlation between methods suggests that the bioassay should be used only as a screening technique for the evaluation of ametryn residues in water.
