Weed population dynamics in transplanted rice

Abstract

A field experiment conducted during kharif, 2014 at college farm, Collage of Agriculture, Rajendranagar, Hyderabad, Telangana state comprised of fourteen weed management practices T1: pretilachlor @ 625 g a.i. ha-1 as pre emergence (PE) at 3 days after transplanting (DAT), T2: pyrazosulfuron ethyl @ 20 g a.i. ha-1 3 DAT, T3: pretilachlor 6% + bensulfuron methyl 0.6% @ 10 kg granules ha-1 as PE at 3 DAT, T4: pyrazosulfuron ethyl @ 20 g a.i. ha-1 at 3 DAT followed by (fb) manual weeding at 25 DAT, T5: penoxsulam @ 22.5 g a.i. ha-1 as early PoE at 12 DAT, T6: cyhalofop-p-butyl @ 100 g a.i. ha-1 as early post emergence (PoE) 15 DAT T7: bispyribac sodium @ 25 g a.i. ha-1 as PoE 25 DAT, T8: azimsulfuron @ 35 g a.i. ha-1 as PoE at 25 DAT, T9: bispyribac sodium @ 25 g a.i. ha-1+ ethoxy sulfuron 18.75 g a.i. ha-1 as PoE at 25 DAT, T10: bispyribac sodium @ 20 g a.i. ha-1+ metsulfuron methyl + chlorimuron ethyl @ 4 g a.i. ha-1 as PoE at 25 DAT, T11: pretilachlor @ 750 g a.i. ha-1 as PE at 3 DAT fb ethoxy sulfuron @ 18.75 g a.i. ha-1 as PoE at 25 DAT, T12: pretilachlor @ 750 g a.i. ha-1 as PE at 3 DAT fb metsulfuron methyl + chlorimuron ethyl @ 4 g a.i.ha-1 as PoE at 25 DAT, T13: hand weeding twice at 25 and 45 DAT and T14: weedy check in randomized complete block design, replicated thrice. Based on importance value index (IVI) Bacopa monnieri among broad leaf weeds, Echinochloa crusgalli among grasses and Fimbristylis dichotoma among sedges were ecologically more dominant weed species.