Abstract:
An experiment was conducted in the field of SAU (Sher-e-Bangla Agricultural
University) farm, Dhaka to screen out the resistant cultivars of onion against
purple blotch disease (Alternaria porn) during the period from October, 2009
to April, 2010. Nine onion cultivars viz. BARI Peas-I, BARl Peas-2, BARl
Peas-3, Thakurgaon local, Faridpur local, Indian big, Manikgonj local,
Taherpuri and Indian small were used as treatments. The screening of the
varieties was done based on different parameters like disease incidence, disease
severity and yield performance. The lowest disease incidence at 30 DAP, 45
DAP, 60 DAP, and 90 DAP respectively were found in BARI Peas-3, Indian
small and Indian big with some extent. The highest disease incidence at 30
DAP, 45 DAP, 60 DAP, 75 DAP, and 90 DAP, were observed in case of local
cultivars Taherpuri, Fridpur local, Thakurgaon local and Manikgonj local. The
highest yield 12.67 t/ha was obtained from BARI Peas-3 followed by Indian
small 10.33 t/ha and Indian big 9.84 t/ha. The lowest yield 4.34 t/ha was
harvested from Taherpuri followed by Faridpur local 4.84 t/ha. In case of
disease reaction 8.00% observed in BARI Peas-3 was graded as resistant
followed by Indian small 10.00%, Indian big 1I .00%, and 18.67% on BARI
Peas-2 this cluster ranked as moderately resistant against Purple blotch . The
local cultivars Taherpuri 37.67%, Faridpur local 35.00%, Thakurgaon local
34.33%, Manikgonj local 34.00% and BARI Peas-l (25.00%) were graded as
susceptible. BAR! Peas-3 performed best in respect of all the parameters
considered against Purple blotch of onion.
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 (MS)
IN
PLANT PATHOLOGY
