screening elite genotypes and ipm of defoliators in groundnut

severe defoliation. Their population varied from 1.24 to 1.72 larvae / m row in first module.
Whereas in second module, the population varied from 0.44 to 0.68 and in case of third
module the population ranged between 2.00 to 2.48 (Table 8).
As per Paired ‘t’ value, all the three modules differed significantly from each other.
Module-II was significantly superior over module-I and module-III during 37 DAS to 79 DAS.
Whereas module-I was significantly superior over module-III during same period.
4.2.3.2 Tobacco caterpillar (Spodoptera litura)
This pest was noticed on the crop from 37 DAS to 79 DAS. They were gregarious in
early instars and scraped the chlorophyll content from under surface of leaves, resulted in
skeletonisation. Later instars spread and fed on leaves voraciously. The population varied
from 1.48 to 3.96 larvae/ m row in first module. Whereas in second module, the S.litura
population ranged from 0.76 to 3.08 and it was varied from 2.56 to 4.40 in third module
(Table 9).
As per Paired ‘t’ value, all the three modules varied significantly from each other.
Module-II was significantly superior over module-I and module-II during 37 DAS to 79 DAS.
However module-I was significantly superior over module-III during same period.
4.2.3.3 Bihar hairy caterpillar (Spilactia obliqua)
Larvae scraped the green matter from under surface of leaves and skeletonised them
in the early instars. The grown up caterpillars defoliated the crop. This pest was found to
attacked the crop 37 DAS to 79 DAS. In M-I the larval number varied from 0.78 to 1.11 / m
row. Whereas in M-II it was varied from 0.28 to 0.70 larvae /m row. However in M-III, the
larval population ranged from 1.04 to 1.69 (Table 10).
As per Paired ‘t’ value, all the three modules varied significantly from each other.
Module-II was significantly superior over module-I and module-III during 37 DAS to 79 DAS.
The same trend was followed with module-I and module-III.
4.2.3.4 Groundnut leaf miner (Aproraema modicella)
Infestation was noticed on the crop for a short period from 51 DAS to 72 DAS. The
larvae were mining into midrib of the leaves and feeding on the mesophyll between the two
epidermal layers for a week and comes out from mine and webbing the leaves and feeding on
them. At later stage to give burnt appearance of leaves from a distance. The population of
GLM varied from 0.92 to 1.20 larvae/ plant in M-I. Whereas in M-II, the leaf miner population
ranged from 0.36 to 0.50 and in M-III, it was varied from 1.82 to 2.04 (Table 11). Though the
pest population was below ETL in all the IPM modules.
Paired ‘t’ value, all the three modules differed significantly from each other. Module-II
was significantly superior over module-I and module-III during 51 DAS to 72 DAS. However
module-I was significantly superior over module-III during same period.
4.2.4 Per cent defoliation by defoliators in different IPM modules of
groundnut
4.2.4.1 35 days after sowing
The per cent defoliation was highest in module-III (36.6) followed by module-I (26.4)
and lowest in module-II (22.8) at 35 days after sowing. As per Paired ‘t’ value, all the three
modules differ significantly from each other (Table 12).