Abstract:
A field experiment was conducted at the experimental farm of Sher-e-Bangla
Agricultural University (SAU), Dhaka, during the period from November‘
2016 to March‘ 2017. The study was done to evaluate the effect of sowing
dates on pumpkin viral diseases and to detect different viruses of selected
sources. In total of four type‘s pumpkin seeds were used in the experiment
which are collected from four sources of Bangladesh, they are Narayanganj
(S
1
), Narshingdi (S
2
), Dhaka (S
3
), and Gazipur (S
). These sources were tested
in two sowing date that were 25
th
4
October‘2016 and 5
th
November‘2016
respectively. The experiment was laid out in a RCBD with three replications.
At early sowing, the highest disease incidence and severity were found
(92.41% and 97.33%, respectively) in S
(Narshingdi) and the lowest disease
incidence and severity were found (63.33% and 81.61%, respectively) in S
2
(Narayanganj). Similarly in late sowing, the highest disease incidence and
severity were found (94.14% and 97.32%, respectively) in S
(Narshingdi) and
the lowest disease incidence and severity were found (57.49% and 82.26%,
respectively) in S
1
2
(Narayanganj). Significant variations were found in both
growth and yield contributing parameters. In both sowing times, the highest
aphid population was found in month of February and the lowest in March.
There were a positive correlation exists between disease incidence (%) and
disease severity with aphid population both in early and late sowing. It revealed
that disease incidence and severity increased with the increase of aphid
population. During experiment, four different categories of symptoms were
identified as viral symptoms in field such as fern leaf, mosaic, chlorosis and
yellowing, and leaf distortion by visual observation. In Serological test, among
1 four types of symptoms mosaic, chlorosis and yellowing confirmed as
Cucumber mosaic virus (CMV) by using CMV antiserum through DAS-ELISA.
Description:
A Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka,
In partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
IN
PLANT PATHOLOGY
SEMESTER: JANUARY- JUNE, 2017
