Ram Devi Timila Ph.D

DOI

ABSTRACT

Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of tomato. Aggressiveness of seven different bacterial wilt isolates collected from Panchkhal, Kavre; Fosre, Myagdi; Balazu and Koteswor, Kathmandu; Nawalpur, Sarlahi; Kumfur, Dhading and Rampur, Chitwan were evaluated under screen house conditions in 1999. Isolate from Myagdi was found the most aggressive whereas Chitwan isolate was the least aggressive. Myagdi isolate overcame the resistance of moderately resistant (L 180) and resistant varieties (L 986). Other tested isolates did not produce any wilt disease in these two varieties. Reactions of the tested isolates in the susceptible variety (L 390) were statistically different in their virulence or aggressiveness. Myagdi isolate resulted in a rapid disease progress in this variety. Number of other management tactics might be necessary in those locations where highly aggressive strain of bacterial wilt is prevalent, as resistant variety alone may not provide adequate protection against the disease.