Agri-R1: Empowering Generalizable Agricultural Reasoning in Vision-Language Models with Reinforcement Learning
Wentao Zhang, Lifei Wang, Lina Lu, MingKun Xu, Shangyang Li, Yanchao Yang, Tao Fang
TL;DR
Agri-R1 addresses data efficiency, interpretability, and cross-domain robustness in agricultural vision-language diagnosis by combining automated reasoning data synthesis with GRPO-based reinforcement learning. A two-stage pipeline first generates reasoning exemplars using DeepSeek-VL2 and filters them with GPT-4, then trains a 3B model with a domain-aware, three-component reward under group-relative policy optimization. Results on CDDMBench show substantial gains in disease recognition (+23.2% relative), knowledge QA (+33.3%), and cross-domain generalization (+26.1 points), with ablations confirming the synergy between reasoning data and GRPO. The approach eliminates manual CoT annotation and delivers data-efficient, interpretable reasoning that remains robust under domain shifts, enabling practical deployment in resource-constrained agricultural settings.
Abstract
Agricultural disease diagnosis challenges VLMs, as conventional fine-tuning requires extensive labels, lacks interpretability, and generalizes poorly. While reasoning improves model robustness, existing methods rely on costly expert annotations and rarely address the open-ended, diverse nature of agricultural queries. To address these limitations, we propose \textbf{Agri-R1}, a reasoning-enhanced large model for agriculture. Our framework automates high-quality reasoning data generation via vision-language synthesis and LLM-based filtering, using only 19\% of available samples. Training employs Group Relative Policy Optimization (GRPO) with a novel proposed reward function that integrates domain-specific lexicons and fuzzy matching to assess both correctness and linguistic flexibility in open-ended responses. Evaluated on CDDMBench, our resulting 3B-parameter model achieves performance competitive with 7B- to 13B-parameter baselines, showing a +23.2\% relative gain in disease recognition accuracy, +33.3\% in agricultural knowledge QA, and a +26.10-point improvement in cross-domain generalization over standard fine-tuning. Ablation studies confirm that the synergy between structured reasoning data and GRPO-driven exploration underpins these gains, with benefits scaling as question complexity increases.
