Abstract:
The present investigation was initiated to evaluate the effects of plant extracts
(neem leaf extract, garlic bulb extract, mahogany bark extract) and cultural
practices (aluminium foil as reflective mulch, coriander as intercrop, marigold as
border crop) for the management of cucumber mosaic viral disease of capsicum.
The experiment was carried out at the research field of Sher-e-Bangla Agricultural
University from November 2020 to April 2021. During the investigation, visual
symptom observation and serological test, DAS-ELISA, confirmed that Cucumber
mosaic virus (CMV) had infected capsicum and various types of symptoms like a
mosaic, shoestring leaf, vein banding and stunted growth were observed in the
field. The highest CMV incidence and severity were found on T
0
(control), 75%
and 45% respectively, whereas the lowest CMV incidence (8.33%) and severity
(22.30%) was observed on T
4
(neem leaf extract). The tallest plants (35.75 cm)
were found in T
5
(aluminium foil as reflective mulch) and the shortest plants were
seen in T
0
(control), 30.33 cm. The maximum number of healthy leaves were
observed in T
5
(aluminium foil as reflective mulch) whereas the lowest number
healthy leaves were found in T
0
(control). The lowest infected leaves and
minimum leaf area reduction (24.33%) was observed in T
4
(neem leaf extract)
compared to T
0
(control). Yield attributes were highest in T
5
(aluminium foil as
reflective mulch) which were the highest number of fruits per plant (13.33),
heaviest fruits (62.10 g), highest fruit yield per plant (725.74 g), highest yield per
plot (2.78 Kg), highest total yield (5.56 ton/ha) and lowest yield loss (17.68%)
compared to T
0
(control). A significant decrease in the number of aphids per leaf
was observed in T
4
(neem leaf extract) compared to T
0
(control) and other
treatments. The correlation-regression analysis established that there was a positive
correlation between CMV incidence and severity. Total yield negatively correlated
with CMV incidence (%) and severity (%) with 74.2% and 95.7% yield reduction
due to an increase of CMV incidence and severity, respectively.
Description:
A Thesis
Submitted to the Department of Plant Pathology,
Sher-e-Bangla Agricultural University, Dhaka
in partial fulfillment of the requirements
or the degree of
CAUSED BY Alternaria spp.
MASTER OF SCIENCE (MS)
IN
PLANT PATHOLOGY
