INTEGRATED MANAGEMENT OF BACTERIAL WILT (Ralstonia solanacearum) OF POTATO

Abstract

An experiment was carried out at the Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during the cropping season 2009-2010 to determine the effect of different management practices and planting dates against bacterial wilt [Ralstonia solanacearum(Smith)Y abuchhi et al.] of potato. A total of eight management practices viz. Cut tuber + Seed treatment with cupravit 5Owp, Cut tuber + Soil treatment with bleaching powder, Cut tuber + Soil amendment with bio-fungicide, Control (Cut tuber), Whole tuber + Seed treatment with cupravit 50wp, Whole tuber + Soil treatment with bleaching powder, Whole tuber + Soil amendment with biofungicide and Control (Whole tuber) and three planting dates viz. 10 November; 25" November and 10" December were used. Cupravit 50wp and bleaching powder were used as seed and soil treating chemicals where biofungicide (Trichoderma harzianum) was applied for soil amendment. The wilt incidence and percentage of dead plants were significantly lower in all the management practices excluding Cut tuber and Whole tuber as Control plots. The lowest (3.23%) wilt incidence was recorded in the management practice of Whole tuber + Soil treatment with bleaching powder followed by 4.16% in Cut tuber + Soil treatment with bleaching powder. Other management practices also reduced disease intensity over Cut tuber and Whole tuber as Control plots but disease incidence was lower in whole tuber plots than Cut tuber plots. Regarding the dates, 25" November planting resulted significant effect in reducing wilt incidence (3.98%) and percentage of dead plants (3.38%) where higher incidences (10.07 and 9.02%, respectively) were found in 10" December planting. The number of tuber per hill (9.62), yield per hill (448.6 g) and yield (26.07 t/ha) were significantly the highest in management practice of Whole tuber + Soil treatment with bleaching powder than Cut tuber plot as Control plot (7.72, 344.9g and 20.77 t/ha, respectively). The yield and yield parameters of potato varied significantly in different planting dates. The significantly highest number of tuber per hill (9.63), yield of tuber per hill (452.6 g) and yield (26.83 t/ha) were recorded in 25" November planting and the lowest (7.48, 324.1g and 18.97 t/ha, respectively) in 10° December planting. Therefore, it may be concluded that planting of whole tubers and soil treatment with bleaching powder played significantly the highest role in reducing bacterial wilt incidence and increasing yield. Planting of 25" November was statistically significant in decreasing bacterial wilt incidence and increasing yield. Soil amendments with bio-fungicide as eco- friendly management practice also resulted better performance in reducing bacterial wilt incidence and in increasing yield over controls.