Abstract:
A field experiment was conducted at central farm and plant pathology lab, Shere-Bangla
Agricultural
University,
Dhaka-1207
from
November
2020
to
March
2022
to study the field response of selected kohlrabi varieties against major
fungal and viral diseases and identification, isolation of causal organisms of
fungal diseases. Five varieties were selected for this experiment viz- Challenger,
Goliath, Bankim, OP Hybrid and Early star, which was collected from Siddik
bazar, Dhaka. The field experiment was carried out in RCBD (Randomized
Complete Block Design) with four replications of each variety in Robi season.
During field response, three diseases were observed at field condition, where
two fungal and one viral disease identified compared with international
literature. They were- Wilt (caused by Fusarium oxysporum), Alternaria leaf
spot (caused by Alternaria brassicae) and Mosaic disease (caused by Turnip
Mosaic Virus). Wilt was observed at seedling condition where variety Bankim
was the most susceptible (1.25%) and lowest incidence was recorded at OP and
Early star variety (0.25%). In case of Alternaria leaf spot, among five varieties
Challenger showed maximum infection (87.47%) and minimum was seen in
Bankim variety (64.45%). In case of growth and yield character significant
variation among all varieties were found. Maximum yield was observed in
variety Bankim (9.80 t/ha) and minimum yield was recorded in variety
Challenger (7.46 t/ha). Respectively, Yield loss was maximum in variety
challenger (45%) and minimum in Bankim (20%). In case of viral disease,
TuMV had the most impact on variety challenger (8.32%) and it greatly reduced
its average fruit weight resulted as 45.12 gm and lowest disease incidence was
observed in variety Bankim (1.09%) and their average fruit weight leads to
119.67 gm. Considering field response against all diseases among all varieties,
variety Bankim has minimum percentage of incidence against all diseases as
well as it gave highest yield in both fungal and viral infections. So Bankim
reflects resistance against all disease response compared to other selected
varieties.
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
