Abstract:
ABSTRACT
Two experiments were conducted to evaluate the efficacy of chemical fungicides for
the management of sheath blight disease of rice at Sher-e-Bangla Agricultural
University, Dhaka, Bangladesh during July 2019 to November 2019, following
randomized complete block design (RCBD) and complete randomized design (CRD)
with 3 replications for in vivo and in vitro experiments, respectively. Sheath blight
disease susceptible variety BR 11 was used in these experiments. Fifteen treatments
viz. T
1
(Tilt 250 EC), T
2
(Combi 230 EC), T
6
(
Awal 72 WP), T
10
(Sunvit 50 WP), T
14
(Contaf 5 EC), T
3
(Filia 525 SE), T
7
(Nativo 75 WP), T
11
(Control
1
(Folicur 250 EC), T
4
(Amister Top 325 SC), T
8
(Autostin 50 WP), T
12
) and T
15
(Control
2
(Score 250 EC), T
5
(Acibin 28 SC), T
9
(Dithane M-45), T
13
) were evaluated against
Rhizoctonia solani causing sheath blight disease of rice (BR 11) in aman season. In
field experiment thirteen fungicides and two controls were used, in which T
14
was
with inoculation and T
15
was without inoculation. After the 4
th
spray the lowest
disease incidence per hill (30%), disease incidence per tiller (10.80%), disease
severity (10.80%) and percent relative lesion height (%RLH), (2.44%) was found in
T
2
treated plot. The highest disease incidence per hill (93.33%), disease incidence
per tiller (44.71%), disease severity (48.36%) and %RLH (9.11%) was found in T
14
after the final spray. In case of yield contributing characters, the highest yield (6.94
ton/ha) and straw yield (7.12 ton/ha) was found in T
2
treated plot while lowest yield
(3.49 ton/ha), straw yield (4.32 ton/ha) observed in T
14
. Moreover, T
3
were
also significantly effective against this disease. In vitro condition at 1000 ppm
concentration all fungicides 100% inhibited the mycelial growth of R. solani. At 250
ppm concentration six fungicides T
1
, T
2
, T
3
, T
4
, T
10
and T
11
completely inhibited the
mycelial growth of R. solani. Among all, fungicides, T
12
gave the worst result to
inhibit the mycelial growth of R. solani.
and T
4
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, 2021
