Pesticide Residue Laboratory, Department of Entomology, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, 173 230 Solan, HP, India.
Chemosphere. 2013 Aug;92(8):949-54. doi: 10.1016/j.chemosphere.2013.02.069. Epub 2013 Mar 29.
A new combinational fungicide formulation trifloxystrobin 25%+tebuconazole 50% (Nativo 75WG), introduced as a part of resistance management strategy, was studied for dissipation behaviour on apple fruits. Nativo 75WG was sprayed twice at the rate of 400 g and 800 g a.i. ha(-1) equal to trifloxystrobin application rate of 100 and 200 g a.i. ha(-1) and tebuconazole at application rate of 200 and 400 g a.i. ha(-1) at four different locations in the Northwest Himalayan region of India. The fruit samples collected at 10d interval and soil samples taken at harvest time were analyzed after second spray. The residual concentrations of trifloxystrobin, its acid metabolite CGA 321113 and tebuconazole were measured. Residues of both fungicides were determined by using gas chromatograph, Agilent 6890N having electron capture detector. The mean initial deposits of trifloxystrobin at four locations were found to be in the range of 0.333-0.387 mg kg(-1) and 0.512-0.714 mg kg(-1) at the application rate of 100 and 200 g a.i. ha(-1), and half-life were found between 19.38-24.93 d and 19.84-28.86 d at the respective doses. The Σ-trifloxystrobin and tebuconazole residues were below determination limit in 40 d apple fruits and soil samples. Initial deposits of trifloxystrobin and tebuconazole were below their Codex MRLs at the respective single doses. The half life value of the tebuconazole deposits ranged between 19.38-25.99 d and 19.84-28.86 d at the respective single and double dose. The study thus suggests 1d pre harvest interval for safe consumption of apple fruit after the application of Nativo 75 WG at single dose.
一种新的复配杀菌剂三氟醚唑 25%+戊唑醇 50%（Nativo 75WG），作为抗性管理策略的一部分被引入，其在苹果果实上的消解行为进行了研究。Nativo 75WG 以 400 g 和 800 g ai ha（-1）的两次剂量喷雾，相当于三氟醚唑应用率 100 和 200 g ai ha（-1）和戊唑醇在印度西北喜马拉雅地区的四个不同地点以应用率 200 和 400 g ai ha（-1）进行喷雾。第二次喷雾后 10d 间隔采集的果实样品和收获时采集的土壤样品进行分析。测定三氟醚唑、其酸代谢物 CGA 321113 和戊唑醇的残留浓度。使用气相色谱仪，Agilent 6890N 型电子俘获检测器测定两种杀菌剂的残留量。四个地点的初始三氟醚唑沉积平均值在 0.333-0.387mg kg（-1）和 0.512-0.714mg kg（-1）范围内，在 100 和 200 g ai ha（-1）的应用率下，半衰期分别为 19.38-24.93d 和 19.84-28.86d。在 40d 苹果果实和土壤样品中，Σ-三氟醚唑和戊唑醇的残留量低于检测限。在各自的单剂量下，初始三氟醚唑和戊唑醇的沉积量低于其法典最大残留限量。戊唑醇沉积半衰期在各自单剂量和双剂量下分别为 19.38-25.99d 和 19.84-28.86d。因此，该研究建议在应用 Nativo 75WG 单剂量后，苹果果实的安全采收间隔为 1d。
