Invasive weed (Parthenium hysterophorus) response to chemical and allelopathic extracts at different stages

Parthenium hysterophorus L. is a noxious alien invasive weed species rapidly spreading in Bangladesh. P. examined the prospects of using allelopathic extracts during period July 2021 to June 2022. Experiments were conducted net house at Sher-e-Bangla Agricultural University, non-cropped areas Khustia and cropped Chudanga. The experiments laid out complete randomized design (CRD) replicated three times separately for each growth stage. Results showed that by pretilachlor, pendimethalin, bensulfuron methyl + acetachlor, oxadiazon, pyrazosulfuron-ethyl pretilachlor decreased seed germination parthenium pot bioassay under both puddle dry sown condition. At rosette stage weed, glyphosate carfentrazone ethyl (5%) with ½, ¾, full doses gave 100% mortality weeks after treatment (WAT). In Ethyl (36%) quizalofop-p-ethyl resulted 90% rate 21 DAT. Overall, efficacy herbicides was more effective on than bolted plants. A phytotoxic response induced aqueous Oryza sativa var. Boteswar, Triticum aestivum BARI gom-21, Helianthus annus L., Datura metel, Mangifera indica Delonix regia, Acacia nilotica. regia most inhibition (29%). Whereas metel Boteswar straw significantly reduced root (1.5 mm) shoot (3.8 length. SAARC J. Agric., 21(1): 239-252 (2023)