MD. IQBAL FARUK
PSO
Plant Pathology Division, BARI, Gazipur
Purple blotch disease, Soil Nutrients, Onion, Tip burn
The experiment was conducted in the field of Plant Pathology Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur.
Pest Management
Diseases, Onion, Fertilizer and manures
The experiment was conducted in the field of Plant Pathology Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur. There were 9 treatments viz. T1= Soil application during seedling transplanting + Spray MP fertilizer at 60 and 75 DAP (@20 g/l), T2= Soil application during seedling transplanting + Spray TSP fertilizer at 60 and 75 DAP (@20 g/l), T3= Soil application during seedling transplanting + Spray Bo fertilizer at 60 and 75 DAP (@20 g/l), T4= Soil application during seedling transplanting + Spray ZnSO4 fertilizer at 60 and 75 DAP (@20 g/l), T5= Soil application during seedling transplanting + Spray CaSO4 fertilizer at 60 and 75 DAP (@20 g/l), T6= Soil application during seedling transplanting + Spray CuSO4fertilizer at 60 and 75 DAP (@20 g/l), T7= Soil application during seedling transplanting + Spray Granular silica gel at 60 and 75 DAP (@20 g/l), T8= Soil application during seedling transplanting + Spray MnSO4 at 60 and 75 DAP (@20 g/l) and T9= Control. The unit plot size was 2 m x 2.5m. RCB design was followed with 3 replications. The variety BARI Piaz-1 was used. The treatments were applied three-time viz. 1st application at the time of seedling transplanting, 2nd application at the time of disease initiation (approx. 60 days after transplanting) and 3rd application 15 days after 2nd application. Data were recorded on purple blotch disease severity, tip-burn incidence, plant growth parameter such as plant height, shoot weight, root length and root weight and yield per unit area. Data on plant growth parameters were recorded 65 days after seedling transplanting. Disease data were recorded 15 days after 3rd-time treatment application. Data were collected on leaf infection and percent Leaf Area Diseased (LAD) and calculated in terms of disease incidence and disease severity (PDI) by following formulae-
The 0-5 disease scoring scale was used to estimate the disease severity (PDI-Percent Disease Index) of purple blotch complex of onion for each unit plot under each treatment. The scale was followed by Islam et al. (1999) and Rahman and Rashid (2008) as described below:
0 = no disease symptoms in the plant
1 = a few spots towards the tip, covering less than 10% leaf area
2 = several dark purplish brown patches covering less than 20% leaf area
3 = several patches with paler outer zone, covering up to 40% leaf area
4 = long streaks covering upto 75% leaf area or breaking of leaves / stalks from the centre
5 = complete drying of the leaves/ stalks or breaking of the leaves / stalks from the base
Data on percent disease index (PDI), total yields kg/plot were collected. The percent data were converted into arcsine transformation values before statistical analysis. Data were analyzed statistically by using the MSTATC program. The treatment effects were compared by applying the least significant different (LSD) test at P=0.05 level.
Annual Research Report 2018-19, Plant Pathology Division, BARI, Gazipur
Report/Proceedings