Abstract

Current study was conducted to assess various survival strategies by morphological and physiological character expressions by the weed, Poa annua, after applying different herbicidal treatments in five contrasting habitats. Morphological traits such as root and shoot length, leaf area, leaf count, dry and fresh leaves, fresh and dry weight were observed and analyzed against different treatments of herbicides. Mineral analysis and measurement of photosynthetic pigments were included in the physiological parameters. Poa annua proved to be an opportunistic plant showing resistance against treatments of Novex, Bromoxynil, Trump and Sulfosulfuron.

Mean root length, mean shoot length were rather promoted after application of Trump and Bromoxynil indicating negative effects of these herbicides. Mean dry leaves, however, increased after every application indicating positive effect on weed plants. Over all, chlorophyll a, b and carotenoids also increased after application. Mineral uptake was favored for few minerals and disfavored for others depicting changes in plant physiology after spraying of herbicides. Current study, based on results, concludes that herbicidal treatment on species did not significantly alter the growth of weed which indicated resistance in plants. So, for management of weed, chemical control proved to be insignificant. Altered strategy of different field doses or using a combination of herbicides is suggested to control weed populations in agricultural fields.

Keywords: Poa annua ; Weed; Ecology; Herbicide; Invasive species