Sustainable Biocontrol Strategies Using Bioactive Weed Fractions Against Alternaria alternata in Cash Crops ": A first report

Climate change increasingly affects agriculture, global biodiversity, and species dispersal, necessitating adaptive strategies for sustainable agricultural practices. In Himachal Pradesh, the agricultural sector is embracing diversification, focusing on producing off-season vegetables such as tomato, capsicum, broccoli, potato, ginger, soybean, oilseeds, and pulses. This shift towards cash crops enhances farmer income and aligns with the region's agro-climatic conditions, promoting economic sustainability. This study investigates the sustainable potential of formulations derived from various weed plants ( Parthenium hysterophorus, Lantana camara, Artemisia roxburghiana ) as biocontrol agents against fungal infections caused by Alternaria alternata in cash crops. Employing GCMS analysis, we identified key bioactive compounds: Beta-Caryophyllene (C15H24) in L. camara, 2-Chloroethyl linoleate (C20H35ClO2) in P. hysterophorus, and 2-(1,2,2-trimethylcyclopenten-3-en-1-yl) acetaldehyde (C10H16O) in A. roxburghiana. These compounds represent a sustainable alternative to synthetic fungicides, aligning with integrated pest management practices that reduce chemical inputs and enhance ecological balance. Molecular docking studies were conducted to evaluate the binding interactions between these bioactive compounds and the Alternaria alternata allergen protein Alt a1, compared to the antifungal drug Fluconazole. Notably, the ligand Tricyclo [4.4.0.01,5] deca-3,5,7,9-tetraene from L. camara exhibited the highest binding affinity (-3.98 Kcal/mol), suggesting its potential as a viable biopesticide. Key residues involved in protein-ligand interactions—VAL32, LYS63, LYS41, and TYR147—were identified as critical targets for mitigating A. alternata infections. This research underscores the significance of utilizing natural plant-derived compounds in sustainable agriculture, contributing to the resilience of cash crops while fostering biodiversity conservation. By integrating such biocontrol strategies, we can enhance food security and promote sustainable farming practices in the face of climate change.