COMPARATIVE PERFORMANCE OF SOME SELECTED ONION CULTIVARS AGAINST stemphylium vesication CAUSING WHITE BLOTCH DISEASE UNDER FIELD CONDITION

Abstract

n experiment was conducted in the Department of Plant Pathology and the field of Sher-e-Bangla Agricultural University (SAU) farm, Dhaka to determined the petformance of some selected cultivers of onion against stemphylium blight disease (Stemphylium vesicariumy during the period from October, 2009 to April, 2010. Nine onion cultivars viz. BARI Peas-I, BARI Peas-2,BAR! Peas-3,Thakurgaon local, Faridpur local, Manikgonj local, Taherpuri Indian big and Indian small were evaluated against the disease.. The petformance were measured on different parameters like disease incidence, disease severity and yield petformance. At seedling stage in net house, no disease incidence were rrecorded in case of BARl Peas-3,Indian big and Indian small, while local cultivars of Faridpur local, Manikgonj local and Thakurgaon local showed disease incidence of 14.33%,13.33% and 13.33% respectively. The lowest disease incidence was found in BARI Peas3, Indian small and Indian big irrespective of different days after transplanting (DAP). 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 recorded in BARI Peas-3 followed by Indian small (10.33 tlha) and Indian big (9.84 tlha).The lowest yield was found in Taherpuri (4.34 tJha) followed by Faridpur local (4.84 tlha). In case of disease reaction, BARI Peas-3 (9.00%) was performed best followed by Indian small (1l.00%), Indian big (11.33%), and BARl Peas-2 (18.00%) regarding stemphylium blight disease. The local cultivars Taherpuri (37.33%), Faridpur local (37.00%), Thakurgaon local (34.33%), Manikgonj local (34.00%) and BARI Peas-I (26.00%) showed poor petformance. BARI Peas-3 petformed best in respect of all the parameters evaluated against stemphylium blight of onion.