MSc

The research work entitled “Integrated management module for sucking pest
complex in chilli Capsicum annuum L.” was carried out at the College of Agriculture,
Vellayani during 2020 to 2022 with the objective to evaluate different integrated pest
management (IPM) modules (M) against sucking pest complex in chilli and the
assessment of insecticide residue in chilli fruits.
A field trial was laid in randomized block design at the instructional farm of the
College of Agriculture Vellayani in plots of 3m×3m with a spacing of 60× 45 cm. The
experiment was conducted in replicated trials and the variety selected was Vellayani
Athulya was planted. In the present investigation, four IPM modules (M) were tested
against the sucking pests in chilli along with KAU POP recommendation as a positive
check. Control plots without any pest management practices were also maintained. Since
insecticidal treatments were included in the IPM modules, harvest time residues of
insecticides were determined on chilli fruits. The QuEChERS method was followed for
the extraction of residues and extracted residues were estimated in Liquid
Chromatography–Mass Spectrometry (LC-MS).
Thrips parvispinus (Karny) was observed for the first time in chilli from Kerala.
The thrips population was found to be more prevalent in the crop's earliest stages than in
its later. In addition to thrips the other sucking pests recorded were aphids Myzus persicae
(Sulzer), mites, Polyphagotarsonemus latus (banks), and whiteflies Bemisia tabaci
(Gennadius).
The results of the present investigation showed that all the IPM modules were
effective in controlling the thrips and aphid population when compared to the untreated
plots. The IPM Module 4 (Chemical intensive module) recorded significantly the lowest
count of thrips and aphids. The other IPM modules M1(organic module), M2 and M3
were statistically on par in their efficacy in controlling thrips and aphids. The mite
population of chilli plants in the present investigation was found lower compared to other
sucking insects and the population was found higher during the later stage of the crop. The
KAU POP recommendation was found effective in controlling the mite population and
recorded a significantly lower population followed by M4. The white fly population was
observed from the 8th week of transplanting and the lowest population was observed in
M4. The leaf curl index was found significantly lower in the chemical intensive module
(M4) followed by other IPM modules at 30 days after transplanting (DAT) and at 60
DAT.
Coccinellid and spider populations were found lower in the chemical-intensive
module (M4). All the other IPM modules recorded significantly higher natural enemy
populations and were statistically on par with each other and with the untreated control.
The M4 module recorded the highest yield (3.03 kg/plot) and BC ratio (1.81). Harvested
chilli fruits were devoid of any insecticide residues.
In the present investigation, T. parvispinus was recorded for the first time in chilli
from Kerala. There were no incidence of S. dorsalis in chilli that speculates a pest
exclusion by T. parvispinus. The chemical-intensive module (M4) was found to be the
most effective in reducing the sucking pest population (M4 - Nursery: Seed treatment
using imidacloprid 70% WS @ 10g kg-1
of seeds, Spraying of thiacloprid 21.7 SC @ 72 g
a.i ha-1
, Main field: Spraying of diafenthiuron 50 WP @ 300 g a.i ha-1 at 2 WAT, spraying
of cyantraniliprole 10.26 OD @ 60 g a.i ha-1 at 4 WAT, spraying of thiamethoxam 25WG
@ 200 g a.i ha -1
at 6 WAT, spraying of spiromesifen 22.9 SC @ 96 g a.i ha-1
at 8 WAT,
spraying of pyriproxyfen 10% EC @ 50 g a.i ha-1
at 10 WAT). The other IPM modules
M1, M2 and M3 were on par in their efficacy against the sucking pests when compared to
other modules. The M4 module also recorded the lowest LCI and highest yield and BC
ratio. The insecticide residues in chilli fruits harvested from different IPM modules were
below the detectable limit.