Decision-Support Tools for Aflatoxin Risk (PGT20) Prediction in Peanuts

This repository contains two R Shiny applications developed to support decision-making for pre-harvest aflatoxin risk prediction in peanut production systems. The tools implement the modeling framework described in the study “Improving Aflatoxin Risk Prediction in Peanut Production: Development of a Decision-Support Tool.” 1. PGT20-DailyTrends An interactive application that allows users to simulate aflatoxin risk trends during the weeks leading up to harvest based on user-provided weather inputs (temperature and rainfall). The tool generates daily predictions of PGT20 under lower-risk and higher-risk scenarios and visualizes predicted risk trajectories together with uncertainty intervals. Daily prediction of PGT20 (probability that peanut loads exceed 20 ppb aflatoxin) Scenario-based forecasts (Lower-Risk and Higher-Risk) based on weather comparison Visualization of risk trends leading up to harvest Live application https://da-young.shinyapps.io/pgt20_tool/ 2. PGT20-Map A spatial visualization tool that displays historical regional patterns of predicted aflatoxin contamination risk across peanut-producing counties in Georgia (2016-2024). Weather data are interpolated using inverse distance weighting (IDW) to generate continuous risk surfaces that illustrate regional variability in environmental conditions associated with aflatoxin contamination. County-level aflatoxin risk prediction Spatial interpolation using Inverse Distance Weighting (IDW) Visualization of risk gradients across the region Live application https://da-young.shinyapps.io/spatial_interpolation_app/