10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 1 2014 (January - March) The fungal pathogen, lessThan i greaterThan Aspergillus niger lessThan /i greaterThan is known to cause decaying in storage onion bulbs and causes black mold not only in lessThan i greaterThan Allium cepa lessThan /i greaterThan but also fungal disease in lessThan i greaterThan Arachis lessThan /i greaterThan and lessThan i greaterThan Vitis lessThan /i greaterThan spp. Post harvest disease of onion causes by lessThan i greaterThan Aspergillus niger lessThan /i greaterThan may be obser lessThan i greaterThan ved lessThan /i greaterThan between bulb scales. Infection of onion seedlings by  lessThan i greaterThan A. niger lessThan /i greaterThan  can become systemic, manifesting only when conditions are conducive. In present studies is focused on the citric acid producing organisms were isolated from lessThan i greaterThan Allium cepa lessThan /i greaterThan bulb and identified morphological characteristics by the microscopic and identified by amylase production test. The isolated fungal species were screened on the acid production using Czapek - dox agar medium and citric acid produced by using lessThan i greaterThan Aspergillus niger lessThan /i greaterThan . DILENDRA CHANDRAKER, SHWETA SAO, YOGESH KUMAR DESHMUKH, LEENA VERMA AND PANKAJ K. SAHU Aspergillus niger, citric acid, Starch hydrolysis test, Onion 144-147