• Effectiveness of practiced management options to control of rice bug

  •   | 
  • 01/04/2016

Joynab Jerin has conducted her BSc thesis with the Department of Agronomy and Agricultural Extension at the University of Rajshahi, Bangladesh.


Climate change leads to reduced rainfall and increasing temperatures. This environment favors the spread of the rice bug (Leptocorisa sp.). Rice bug causes reduced growth or deformation of rice grains which reduced productivity of the rice crop and leads to financial losses for the farmers.

This study wanted to identify a sustainable management option for rice bug by comparing the effectivity of different insecticide options.

An experiment was conducted in SAF-BIN project locations in the upazillas[1] Baraigram (Natore district), Paba (Rajshahi district) and Patnitala (Naogaon district), Bangladesh. BRRI dhan57 a drought tolerant rice variety was used. The two tested insecticide options were: T1= Amritapani + snails and T2 = Malathion[2]. The treatments were arranged in a randomized complete block design with three replications. 21-25 day old seedling were transplanted in a rate of 3-4 seedlings/hill, spaced 20cm x 14 cm. Data on growth duration (days), fertile tillers/hill, thousand grain weight (TGW), yield, pest incidence was collected.

Growth duration was longest in Patnirala, lowest in Baraigram. T2 plots achieved more fertile tillers/hill (T1: 11.9-12.8; T2: 12.2-13.4) (no significant difference). TGW was mostly higher in plots with T2 (T1: 18.9-19.4g; T2: 19-19.4g) (no significant difference). In all locations higher yield was achieved under T2 (range: T1: 3.9-4.2t/ha; T2: 4.1-4.4t/ha) (no significant difference). More panicles were affected in T1 plots in Patnitala and Paba, more in T2 plots in Baraigram. More grains/panicle were affected under. The pest incidence was higher in T2.. There was a strong positive correlation R2= 0.87 between pest incidence and grain damage.

Concluding from the results of this experiment snails mixed with melathion could be suggested for sustainable rice bug management and large scale dissemination. Neither treatment required spraying directly on the pollinating panicles in this manner not hampering pollination.

[1] a geographical region in Bangladesh used for administrative purposes, sub-units of districts. (Wikipedia, 2015: access date 19/10/2015.

[2] Malathion is an organophosphate used as insecticide.