STUDY ON THE POST HARVEST DISEASES OF POTATO IN THE WHOLE SALE MARKETS OF DHAKA

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.