This paper presents PlantDeBERTa, a high-performance open-source language model specifically designed to extract structured knowledge from plant stress response literature. Based on the DeBERTa architecture, it is fine-tuned using a carefully curated corpus of expert-annotated abstracts focusing on diverse biotic and abiotic stress responses in lentils (Lens culinaris). Combining Transformer-based modeling, rule-based language postprocessing, and ontology-based entity normalization, it accurately and semantically captures biologically meaningful relationships. The annotated base corpus, using a hierarchical schema aligned with the crop ontology, encompasses molecular, physiological, biochemical, and agronomic dimensions of plant adaptation. PlantDeBERTa demonstrates strong generalization across diverse entity types, demonstrating the feasibility of robust domain adaptation in resource-poor scientific fields. By providing a scalable and reproducible framework for high-resolution entity recognition, it addresses a critical gap in agricultural NLP and paves the way for intelligent, data-driven systems in plant genomics, phenotyping, and agricultural knowledge discovery. Models are distributed openly to increase transparency and accelerate interdisciplinary innovation in computational plant science.