HomeInternational Rice Research Notesvol. 22 no. 3 (1997)

Weed control practices for improving N use efficiency and productivity of flood-prone lowland rice

A Ghosh | L. C. Prasad

Discipline: Agriculture, Pest Management



Flood-prone lowland rice in eastern India is mostly dry-sown through broadcasting seeds on poorly prepared fields, a practice resulting in early weed infestation and inefficient use of basally applied fertilizers. Nitrogen use efficiency can be improved by controlling weeds through off-season tillage operations and adopting mechanical or chemical methods in the early stages.


We investigated the effects of tillage, weed control practices, and N fertilizer on the performance of rice during 1994 at Cuttack, India. A split-plot design, with tillage in main plots and combinations of weed control and N fertilizer in subplots, was used in three replications. The crop was grown in plots plowed in summer (Mar) and/or before sowing (late May) or transplanting (late July) (conventional tillage) with or without basal application of 40 kg N ha-1. The crop was sown in dry soil on 1 Jun using 400 seeds m-2 at 20-cm row spacing, and sprayed with thiobencarb at 2kg ha-1 within a week of sowing or subjected to beushani at 42 d after water accumulated in the field. Puddling was also included as an additional treatment for comparison, where 42-d-old seedlings were transplanted at 20- × 15-cm spacing using 3-4 seedlings hill-1. Gayatri, a semidwarf, long-duration, photoperiod-sensitive rice variety, was used in the experiment.