Abstract:
A study was conducted to observe the prevalence of post harvest diseases of
potatoes and to identify their causes in the whole sale markets of Dhaka. The
experiment was conducted in the MS Laboratory of Department of Plant
Pathology, Faculty of Agriculture, Sher-e-Bangla Agricultural University during
the period of July, 2016- May, 2017. Samples were collected from five noted
whole sale markets of Dhaka viz. Karwan bazar, Town hall market, Mirpur-1,
Mirpur-10 and Khilkhet bazar. During each visit 5 kgs of potatoes were collected
randomly from each of the market places. Total 400 potato samples were
investigated and diseased potatoes were sorted out. The most frequent diseases
found in the collected samples were common scab, brown rot, soft rot, Fusarium
dry rot etc. Pathogens were isolated by tissue planting method and dilution plate
method for fungi and bacteria respectively. Several biochemical tests like Gram’s
staining, Levan test, KOH solubility, Starch hydrolysis, Oxidase, Catalase,
Gelatin, liquification and potato soft rotting test were conducted to identify and
determine the characteristics of disease causing agents of collected potatoes.
The study revealed that collected samples were infected by Fusarium spp.
causing Fusarium dry rot (3.97%), Ralstonia solanacearum causing brown rot
(4.27%), Streptomyces scabies causing common scab of potato (5.90%),
Pectobacterium sp causing soft rot of potato (3.68%) and the prevalence of
physiological disorder were recorded (5.48%). This study reveals the fact that
potatoes are subject to various disease in the markets of Dhaka.
Description:
A Thesis
Submitted to the Department of Plant PathologySher-e-Bangla Agricultural University, Dhaka
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (M.S.)
IN
PLANT PATHOLOGY
Semester: Jan-Jun, 2016