Abstract
Nine experiments were conducted at the Plant Pathology Laboratory (Gazipur) and TCRC (Bogra) of Bangladesh Agricultural Research Institute during 2007-2010. Stem canker and black scurf caused by Rhizoctonia solani is a major disease of potato in Bangladesh. The pathogen is soil-borne and seed-borne having a high degree of survivability. Traditional control measure by a single method is not effective in minimizing the infection and spread of the disease. Integrated management approach might be an effective alternative. Different components of control measure such as chemical, biological and cultural were investigated individually; afterwards, the best treatments of each component were incorporated into integrated disease management studies. The results revealed that increase in inoculum level caused higher infection on progeny tubers. Number of russet, deformed and sclerotia bearing tubers were higher when 100% infected tubers were Sown. Some chemicals were tested for seed tubers treatment of which Amistar, Bavistin and Vitavax were effective. Seed treatment with Boric acid (3%) was comparable to that with healthy seed tubers. Amistar, Bavistin and Provax were effective against soil- borne inocula of the pathogen. Nineteen potato germplasms were screened for resistance against Rhizoctonia solani, only three of them (Raja, Herra, BARITPS-1) showed moderatey resistant reaction. The effect of organic amendments against stem canker and black scurf of potato was studied. Poultry refuse (5 t/ha) and mustard oil cake (500 kg/ha) were effective in reducing incidence and severity of the disease. Five isolates of Trichoderma harzianum were tested as antagonist to Rhizoctonia solani in vitro. All of them except TM14 were effective in reducing radial growth of Rhizoctonia solani on PDA. Integration of poultry refuse (5t/ha) + furrow application of Amistar (0.1%) + scil drenching of Amistar (0.1%) (45 days after sowing) was effective for the management of the disease. Integration of poultry refuse (5t/ha) + furrow application of Amistar (0.05%) + soil drenching of Amistar (0.05%) (45 days after sowing) was also effective. From the results of the study, it is concluded that stem canker and black scurf of potato can be controlled by integration of application of poultry refuse (5t/ha) + furrow application of Amistar (0.1%) + soil drenching of Amistar (0.1%) (45 days after sowing).