Chlorpyrifos is one of the most used insecticides in agro-ecosystems and is repeatedly applied due to the increase in pest resistance, which leads to environmental accumulation. The aim of this work was to evaluate the effect of chlorpyrifos on growth and aflatoxin B₁ (AFB₁) production by four Aspergillus section Flavi strains, under different water conditions—a_W (0.93, 0.95 and 0.98)—on maize-based medium (MMEA) and maize grains supplied with 0.06 to 1.4 mmol/L of chlorpyrifos. MMEA plates were incubated at 18, 28, and 37 °C and plates with maize grains at 25 °C during 21 days. Chlorpyrifos stimulated the growth and AFB₁ production of non-target organisms, such as Aspergillus section Flavi strains, both at low (0.06 mmol/L) and at high concentrations (1.4 mmol/L) on MMEA and maize grains. Stimulation occurred over a wide range of temperature and a_w conditions. The toxin concentration produced by the two strains on MMEA at 18 °C increased when the concentration of chlorpyrifos also increased, being most significant at 0.6 mmol/L. In conclusion, the presence of chlorpyrifos should be considered as a factor, together with environmental conditions, for the development of effective production practices of maize grains, in order to avoid fungal growth and AFB₁ production, to prevent both economic losses and risks to human and animal health.

毒死蜱是农业生态系统中最常用的杀虫剂之一，由于害虫抗性增加，导致环境积累，因此被反复使用。这项工作的目的是评估毒死蜱对四种Aspergillus section Flavi菌株的生长和黄曲霉毒素 B ₁ (AFB ₁ ) 产量的影响，在不同的水条件下——a _W（0.93、0.95 和 0.98）——在基于玉米的培养基上(MMEA) 和玉米粒提供 0.06 至 1.4 mmol/L 毒死蜱。MMEA 板在 18、28 和 37°C 下孵育，玉米粒在 25°C 下孵育 21 天。毒死蜱刺激非目标生物的生长和 AFB ₁产生，例如曲霉部分Flavi菌株，在 MMEA 和玉米粒上的低浓度 (0.06 mmol/L) 和高浓度 (1.4 mmol/L)。刺激发生在很宽的温度范围和_w条件下。当毒死蜱浓度也增加时，两种菌株在 MMEA 上在 18°C 产生的毒素浓度也增加，在 0.6 mmol/L 时最为显着。总之，毒死蜱的存在应与环境条件一起被视为制定玉米谷物有效生产实践的一个因素，以避免真菌生长和 AFB ₁生产，防止经济损失和人类风险和动物健康。