AgriChain Visually Grounded Expert Verified Reasoning for Interpretable Agricultural Vision Language Models

TL;DR

AgriChain introduces a large expert-verified dataset and a specialized vision-language model that significantly improves plant disease diagnosis accuracy and interpretability in agriculture.

Contribution

The paper presents AgriChain, a new expert-verified dataset and a fine-tuned model that enhances disease prediction and reasoning interpretability in agricultural vision-language tasks.

Findings

Model achieves 73.1% top-1 accuracy on test set.

Expert-verified explanations closely match human reasoning.

Supervised reasoning improves both accuracy and interpretability.

Abstract

Accurate and interpretable plant disease diagnosis remains a major challenge for vision-language models (VLMs) in real-world agriculture. We introduce AgriChain, a dataset of approximately 11,000 expert-curated leaf images spanning diverse crops and pathologies, each paired with (i) a disease label, (ii) a calibrated confidence score (High/Medium/Low), and (iii) an expert-verified chain-of-thought (CoT) rationale. Draft explanations were first generated by GPT-4o and then verified by a professional agricultural engineer using standardized descriptors (e.g., lesion color, margin, and distribution). We fine-tune Qwen2.5-VL-3B on AgriChain, resulting in a specialized model termed AgriChain-VL3B, to jointly predict diseases and generate visually grounded reasoning. On a 1,000-image test set, our CoT-supervised model achieves 73.1% top-1 accuracy (macro F1 = 0.466; weighted F1 = 0.655), outperforming strong baselines including Gemini 1.5 Flash, Gemini 2.5 Pro, and GPT-4o Mini. The generated explanations align closely with expert reasoning, consistently referencing key visual cues. These findings demonstrate that expert-verified reasoning supervision significantly enhances both accuracy and interpretability, bridging the gap between generic multimodal models and human expertise, and advancing trustworthy, globally deployable AI for sustainable agriculture. The dataset and code are publicly available at: https://github.com/hazzanabeel12-netizen/agrichain