Abstract:
Information was collected from papaya growers and DAE personnel of ten districts
namely, Dhaka, Rajshahi, Kustia, Gazipur, Pabna, Norsindhi, Tangail, Joypurhat,
Natore and Bogura during November 2017 to December 2018 to assess the
diversity of insect pests of papaya and its management practices used by growers.
Descriptive statistics, Pearson product moment correlation coefficient, were used
for analysis. Four insect pests namely mealybug, fruit fly, ant and mite were
reported by the growers as well as DAE personnel. Among the papaya growers
most (98%) of them were male and only 2% were female. Majority of them
(40.67%) were middle aged (41-50 years) farmers compare to old aged (51-60 years)
which occupied 34.67%. Most of the papaya growers 65.33% could not read or write but
could sign only. Highest experience category of papaya growers were medium category
(86.67%) followed by low category (12.0%). For seed use, the highest percentage of the
farmers 50.33%) used their own seed followed by 23.67% and 21.33% were used seeds of
company and neighbor, respectively. In case of pest occurrence in the papaya field
48.15% respondents expressed that papaya mainly infested by mealybug followed by
whitefly (27.45% farmers), mite (20.39% farmers) and ant (4.01% farmers). Among the
pests, mealybug and ant were reported to infest leaf, stem, flower and fruits but whitefly
and mites were reported as leaf infesting pests. Low (8.70%), medium (47.83%) to high
level (43.48%) severity of infestation was reported by the farmers and majority of the
farmers (55.56%) reported medium severity of whitefly infestation. All farmers (100%)
reported mealybug as a major pest of papaya, followed by 35.23% and 24.76% farmers
reported whitefly and mite, respectively as major pests of papaya. Farmers used Marshal
20EC, Sumithion 50EC, imitaf 20SL or tido 20SL 3-4 times for controlling mealybug,
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imitaf 20SL or tido 20SL and aktara 20WG 1-2 times for controlling whitefly and
sunmectin 1.8EC/ acamite 1.8EC / vertimec 1.8EC for controlling mite.Most of the
farmers (65.27%) opined that mealybug infested in the papaya plant at fruiting stage and
infestation occurred on leaf, stem, flower and fruit with medium to high severity of
infestation but maximum infestation was reported from fruit (36.31% farmers opinion)
followed by flower infestation (34.24% farmers opinion). Majority of the farmers
(96.42%) applied insecticides to control mealybug and marshal 20EC, sumithion 50EC,
imitaf or tido 20SL and caught 10EC were used 3-4 times by the farmers. But majority of
the farmers (47.52%) sprayed imitaf 20SL/tido 20SL 3-4 times for controlling mealybug.
In responding effectiveness of insecticides, most of the farmers (93.33%) reported that
mealybug was controlled by insecticides spraying and 6.67% farmers reported
ineffectiveness of insecticides. Most of the papaya growers (96.67%) were conscious
about hazardous effect of chemical insecticides and most of them (96.93%) reported
health hazards.
Description:
A Thesis
Submitted to the Department of Entomology
Sher-e-Bangla Agricultural University, Dhaka
In partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
ENTOMOLOGY
SEMESTER: JANUARY-JUNE, 2017