Abstract:
The relative efficiency of endosulfan (0.05%), phosphamidon (0.03%),
monocrotophos (0.05%), carbaryl (0.15";,) and HCH (0.15%) and their joint
formulations with carbaryl against the tea mosquito bug Helopeltis antonii Signoret
was evaluated in a field experiment conducted in the Cashew Research Centre,
Madakkathara, Trichur during two consecutive years 1 980-81 and 1 981 -82. Three
rounds of sprayings were given in each year using a rocker sprayer Fitted with
'hi-tree' lance attachment at the times of new vegetative flush formation, panicle
emergence and at fruit set initiation. The intensity of pest damage was recorded
from twenty numbers of randomly selected shoots and panicles on a 0-4 scale.
All the insecticides and their joint formulations were effective in reducing
the intensity of damage by the mosquito bugs. Ths joint application of
phosphamidon (0,015%) + carbaryl (0.075^) was consistently superior to endosulfan
(0.025%) + carbaryl (0.0755') and HCH (0.15#) in reducing shoot and
panicle damage.
HCH (0.075%) -f- carbaryl (0.075%) was on par with phosphamidon
(0.015%) + carbaryl (0-075%) in reducing the infestation. However, the
conjunctive use of insecticides did not show superior performance as compared
to their individual applications, except in the case of HCH + carbaryl in which case,
the combined application was found to be superior to HCH. But this mixture was
not superior to carbaryl applied alone.
