Xiao Shenglan, Li Zijian, Fantke Peter
School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, China.
Quantitative Sustainability Assessment, Department of Technology, Management and Economics, Technical University of Denmark, Lyngby, Denmark.
Pest Manag Sci. 2021 Nov;77(11):5096-5108. doi: 10.1002/ps.6549. Epub 2021 Jul 22.
There is a continuous need to advance pesticide plant uptake models in support of improving pest control and reducing human exposure to pesticide residues. The periderm of harvested root and tuber crops may affect pesticide uptake, but is usually not considered in plant uptake models. To quantify the influence of the periderm on pesticide uptake from soil into potatoes, we propose a model that includes an explicit periderm compartment in the soil-plant mass balance for pesticides.
Our model shows that the potato periderm acts as an active barrier to the uptake of lipophilic pesticides with high K , while it lets more lipophobic pesticides accumulate in the medulla (pulp). We estimated bioconcentration factors (BCFs) for over 700 pesticides and proposed parameterizations for including the effects of the periderm into a full plant uptake modeling framework. A sensitivity analysis shows that both the degradation half-life inside the tuber and the lipophilicity drive the contributions of other aspects to the variability of BCFs, while highlighting distinct dynamics in the periderm and medulla compartments. Finally, we compare model estimates with measured data, showing that predictions agree with field observations for current-use pesticides and some legacy pesticides frequently found in potatoes.
Considering the periderm improves the accuracy of quantifying pesticide uptake and bioconcentration in potatoes as input for optimizing pest control and minimizing human exposure to pesticide residues in edible crops.
持续需要改进农药植物吸收模型，以支持改善害虫防治并减少人类接触农药残留。收获的块根和块茎作物的周皮可能会影响农药吸收，但在植物吸收模型中通常未被考虑。为了量化周皮对农药从土壤吸收到马铃薯中的影响，我们提出了一个模型，该模型在农药的土壤-植物质量平衡中纳入了一个明确的周皮隔室。
我们的模型表明，马铃薯周皮对高K的亲脂性农药的吸收起到了积极的屏障作用，而它会让更多的疏脂性农药在髓（果肉）中积累。我们估计了700多种农药的生物富集系数（BCFs），并提出了将周皮效应纳入完整植物吸收建模框架的参数化方法。敏感性分析表明，块茎内部的降解半衰期和亲脂性都驱动了其他方面对BCFs变异性的贡献，同时突出了周皮和髓隔室中不同的动态变化。最后，我们将模型估计值与实测数据进行比较，结果表明预测值与当前使用的农药以及马铃薯中常见的一些遗留农药的田间观测结果一致。
考虑周皮可提高量化马铃薯中农药吸收和生物富集的准确性，为优化害虫防治和最大限度减少人类接触食用作物中的农药残留提供依据。
