Association Between Abiotic Factors and Chili Aflatoxin Contamination in Sindh Province, Pakistan, in Two Years with Contrasting Rainfall Patterns

Aflatoxins, carcinogenic secondary metabolites produced by Aspergillus flavus and related species, contaminate various economically significant crops, posing serious health risks to humans and resulting in substantial economic losses due to trade rejections. Chili, a prominent cash crop of Pakistan contributing to the country's gross domestic product, has experienced a decline in production and export due to aflatoxin contamination exceeding regulatory limits. Abiotic factors are known to modulate A. flavus growth, crop stress, and subsequent accumulation of aflatoxins in crops. In this study, the potential impact of soil and weather factors on chili aflatoxin contamination was examined over 2 years with contrasting rainfall patterns. Chili aflatoxin concentrations were significantly lower in the year with frequent, heavy rainfall, suggesting that drought stress plays an important role in contamination risk. The association between soil properties and chili aflatoxin contamination varied between the 2 years, suggesting that interactions between soil moisture and fertility impact fungal growth and aflatoxin production. The results indicate that drought stress is a major contributor to aflatoxin contamination risk in chili that should be considered in the context of climate change and increased frequency of extreme weather events in Pakistan. Furthermore, improved irrigation management and soil amendments should be a focus of aflatoxin mitigation research for chilies in Pakistan. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .