Abstract:
Experiments were conducted in Dhaka, Kathalbaria and Kholabaria villages of Laxsmipur
union of Natore district, Bangladesh to identify the causal agents of anthracnose disease of
Aloevera (Aloe vera L.) and for its field management during 2017-18. The causal organism
Colletotrichum gloeosporioides was isolated by tissue plating method and identified based on
morphological and cultural characteristics that was confirmed by pathogenicity test. Eleven
treatments including chemicals, botanicals, bio agents and traditional practices viz. Folicur 25
EC (Tebuconazole @ 0.1%), Tilt 250 EC (Propiconazole @ 0.1%), Autostin 50 WP
(Carbendazim @ 0.2%), Dithane M 45 (Mancozeb @ 0.2%), Companion
(Mancozeb+Carbendazim @ 0.2%), Bordeaux mixture (CuSO
4
+CaO @ 01 %), Lime (CaO @
0.5%), Trichoderma harzianum (Bio agent @ 0.2%), Garlic bulb extract 1:1 (w/v) (Allium
sativum @ 1 %), Neem leaf extract 1:1 (w/v) (Azadirachta indica @ 1%) and Alamanda leaf
extract 1:1 (w/v) (Allamanda cathartica @ 1 %) were considered for the management of
anthracnose disease of Aloevera. An infested farmer’s field was selected in Kholabaria and
Kathalbaria villages of Laxmipur union of Natore district in rainy season for this experiment.
The experiment was conducted by following RCBD design with three replications. Among the
treatments, Bordeaux mixture gave best result against this disease. Moreover, Tilt 250 EC and
Folicur 25 EC and Garlic bulb extract showed better effect against the disease than the other
treatments. Lime also has moderate effect against anthracnose disease of Aloevera. In 2017,
after 4
th
spray, the the lowest plant incidence was recorded in Bordeaux mixture (58.33%)
which was statistically identical with Folicur (64.58%), Tilt (64.58%) and Garlic bulb extract
(66.67%). Similarly, the lowest disease severity was found in Bordeaux mixture (3.55)
followed by Folicur (5.67%), Tilt (6.67%) and Garlic bulb extract (7.67%). Similar result also
found in 2018. After 4
th
spray, the lowest plant incidence was recorded in Bordeaux mixture
(38.58%) which was statistically identical with Lime (41.66%) and Garlic bulb extract
(45.83%). Similarly, the lowest disease severity was found in Bordeaux mixture (0.20%)
followed by Lime (0.25%) and Garlic bulb extract (0.36%). Considering the overall
performance of the treatments, garlic bulb extract could be used as eco-friendly approach.
Moreover, use of Bordeaux mixture is better than the traditional use of lime. From chemical
pesticides, Tilt 250 EC and Folicur 25 EC could be used for controlling the disease as the last
option.
Description:
A Thesis
Submitted to the Department of Plant Pathology
Sher-e-Bangla Agricultural University, Dhaka,
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE
IN
PLANT PATHOLOGY