Weed Flora Diversity and Community Structure Across Agricultural and Disturbed Habitats of Davangere District, Karnataka, India

Weed lora was surveyed in and around Davangere taluk (Karnataka, India), with focused sampling across the neighbouring localities of Kurki and Tholahunase. Strati ied quadrats were laid in representative habitats, rain ield and irrigated crop ields, fallows, ield margins, roadsides, and canal banks during the monsoon and post-monsoon seasons. Specimens were identi ied using regional loras, and community structure was described using relative frequency, density, and Importance Value Index. The weed assemblage was dominated by Asteraceae, Poaceae, and Amaranthaceae. Widely distributed and persistent species included Parthenium hysterophorus, Ageratum conyzoides, Chromolaena odorata, Lantana camara (in shrub thickets), Cynodon dactylon, Echinochloa colona, Dactyloctenium aegyptium, Cyperus rotundus, Commelina benghalensis, Trianthema portulacastrum, Alternanthera sessilis, Amaranthus spinosus, and Euphorbia hirta. Habitat iltering was evident: grasses and sedges predominated in cultivated and intermittently looded sites, while invasive asters were most abundant along disturbed roadsides and fallows. Seasonal turnover favored fast-growing annuals during kharif, with perennial rhizomatous weeds maintaining a year-round presence. The prevalence of aggressive invasives—especially P. hysterophorus and C. odorata—poses risks to crop productivity, native understory, and human/animal health. Integrated weed management is recommended, combining timely manual/mechanical removal before lowering, residue mulching, competitive cover crops, optimised crop spacing, and judicious, rotation-based herbicide use. Community awareness and coordinated control along linear habitats (roadsides, canal banks) are critical to reduce reinvasion pressure. This baseline assessment provides site-speci ic priorities for weed control and a framework for monitoring management effectiveness across the Davangere University landscape, including Kurki and Tholahunase.