The experiment was conducted at the Field Laboratory, Department of Plant Pathology, Bangladesh Agricultural University (BAU), Mymensingh during the period from 21 August 2011 to 12 December 2011. A high yielding cultivar of rice 'BR14' was selected for this study. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Distances between the blocks and between the plots were 50 cm and 25 cm, respectively. The size of unit plot was 2m×1.5m. A total of seven treatments were used, viz. T1 (Control no spray), T2 (Compost tea as foliar spray), T3 (Compost tea as soil drenching), T4 (Tilt 250 EC as foliar spray), T5 (Tilt 250 EC as soil drenching), T6 (Bavistin 50 WP as foliar spray) and T7 (Bavistin 50 WP as soil drenching). The land used for seed bed was marshy and no fertilizers were applied. Clean and mature seeds were soaked in tap water for 24 hours and incubated 48 hours for germination before sowing in the seed bed. The germinated seeds were sown uniformly in the seed bed.
Preparation of Compost tea
Compost tea was obtained by mixing compost with tap water at a ratio of 1:5(w/v) followed by fermentation for one week. It was stirred once in every day and allowed to ferment in the Nethouse, Seed Pathology Centre, BAU, Mymensingh at 25°C. After 7 days, the solution was filtered through cheese cloth. The prepared compost tea was ready for application with ordinary sprayers.
Application of fertilizer and manures
The chemical fertilizers were applied in the field as per recommended dose of Bangladesh Rice Research Institute (BRRI). TSP, MoP, Gypsum and Zinc sulphate except urea were applied (all plots) at the time of final land preparation. Urea was applied in equal splits at 15, 30 and 45 days after transplanting. Organic amendments with cowdung (10 ton/ha), Neem oil cake (150 kg/ha) and Mustard oil cake (133 kg/ha) were also accomplished at the time of final land preparation.
Transplanting of rice seedling in experimental plots
After preparing the land, 32 days old seedlings of BR 14 were uprooted carefully to avoid root injury. The seedlings were transplanted in the experimental plots using three seedlings/hill. Plant to plant and row to row spacing were 15 cm and 20 cm, respectively. In case of missing hill necessary gap filling was done at 10 days after transplanting. Weeding was done twice.
Recording of Diseases Severity in the Field
Data were recorded visually by observing the symptoms at booting and ripening stages. Four leaves from the top of the plant were considered for grading the severity of diseases. Five plants in each plot were randomly selected for recording the disease severity and the selected plants were tagged. The severity of two diseases viz. brown spot and narrow brown spot were recorded (0-9 scale) following Standard Evaluation System for Rice (IRRI, 1980). The grading scale for brown spot of rice was 0 = No incidence, 1 = Less than 1% area affected, 2 =1-3% areas affected, 3 = 4-5% areas affected, 4 = 6-10% areas affected, 5 = 11-15% areas affected, 6 = 16-25% areas affected, 7 = 26-50% areas affected, 8 = 51-75% areas affected and 9 = 76-100% areas affected. The grading scale for narrow brown spot of rice was 0 = No incidence, 1 = Less than 1% area affected, 3= 1-5% areas affected, 5= 5-25% areas affected, 7 = 26-50% areas affected and
9= 51-100% areas affected
Data Collection on growth and yield Analysis
The data were collected on the growth and yield parameters of rice. These data were analyzed statistically and the treatment means were compared by Duncan's Multiple Range Test (DMRT).