An inventory of weed diversity data including invasive alien species as emerging threats to agro-ecosystem

Abstract

Weed invasion has emerged as one of the foremost ecological and agricultural challenges, undermining crop productivity and threatening native biodiversity. Agricultural landscapes, particularly in regions of high cultivation intensity, provide ideal conditions for establishing and spreading invasive alien plants. Weed flora was surveyed across ten cultivated fields at six sites in Mysore district, Karnataka, India with monthly visits over 12 months; 1-hectare focal fields; 4 quadrats per field to document species diversity and assess invasive potential. About 51 species was recorded (42 genera, 22 families); Asteraceae (n = 11) and Poaceae (n = 10) were dominant. Parthenium hysterophorus L. was the most widespread (present in 9/10 fields). Using authoritative databases, we classified 15 species as invasive (29.41%). Ethnobotanical interviews indicated mixed local perceptions: several species have medicinal uses that complicate management. Ecological traits that facilitate invasion and recommend targeted early detection, community-based monitoring, and integrated weed management tailored to smallholder cropping systems.