Cogent Food & Agriculture (Dec 2022)

Efficacy of pre- and post-emergence herbicide combinations on weed control in no-till mechanically transplanted rice

  • Biplab Mitra,
  • Koushik Patra,
  • Prateek Madhab Bhattacharya,
  • Arunava Ghosh,
  • Apurba Kumar Chowdhury,
  • Tapamay Dhar,
  • Saiful Islam,
  • Alison M Laing,
  • Mahesh K Gathala

DOI
https://doi.org/10.1080/23311932.2022.2139794
Journal volume & issue
Vol. 8, no. 1

Abstract

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AbstractNo-till mechanized-transplanted rice was evaluated for different combinations of pre- and post-emergence herbicides to determine feasible, economically viable weed management options to control complex weed flora in rice fields. All pre-emergence herbicides significantly reduced the population of grassy weeds; of these, pendimethalin resulted in the greatest reductions (83%) at 15 days after transplanting (DAT). Among five post-emergence herbicide treatments, the combination of bispyribac-sodium (10%SP) + pyrazosulfuron (10%WP) was found to be the most effective in controlling all weed flora at both 35 and 55 DAT. The sequential application of pendimethalin (pre-emergence) followed bispyribac-sodium + pyrazosulfuron (post-emergence) resulted in significantly higher rice grain yield (4.4 t-ha−1) and relative gross-margin (417 USD-ha−1) than all other treatments. A strong negative correlation was observed between rice grain yield and weed biomass, and a strong positive correlation between rice grain yield and weed control efficiency. Our findings demonstrate the potential to combine pre- and post-emergence herbicides in no-till mechanized-transplanted rice; these findings have applications globally in regions where rice is established by no-till or mechanized transplanting.

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