Abstract:
Stem borer (Chilo partellus) is the most destructive pest of maize causing considerable yield losses especially during yala season. At present the pest is managed through whorl application of insecticide granules or foliar spraying of liquid formulations of insecticides. However, effective control of the pest cannot be expected from liquid formulations due to practical difficulties in the spraying especially at the
mature stages of the crop. Hence, investigations were carried out in two consecutive yala seasons in
2008 and 2009 to study the efficacy of granular type insecticides against the stem borer. The maize hybrid variety Sampath was used. Four insecticides were tested along with an untreated control. Insecticides were applied twice as whorl applications at 2 week interval.
The percentage stem borer damage in plots treated with Diazinon 5G, Fipronil 0.3G and Thiocyclam
hydrogen oxalate 4G found to be < 8% as compared to > 35% damage in untreated control. Larval
population and severity of stem borer damage were also significantly low in Diazinon 5G, Fipronil 0.3G
and Thiocyclam hydrogen oxalate 4G treated plots during both seasons over the control. The percentage seed yield in Diazinon 5G, Fipronil 0.3G and Thiocyclam hydrogen oxalate 4G treated plots found
to be 52-91% and 28-44% higher than the untreated control during yala 2008 and 2009 respectively.
Therefore, Fipronil 0.3G and Thiocyclam hydrogen oxalate 0.4G can be recommended in addition to
the present recommendation of Diazinon 5G for the control of stem borer in maize.
