R. Momotaz
Plant Pathology Division, BARI, Gazipur
Integrated management, Marigold, Sclerotinia sclerotiorum
The experiment was conducted at the plant pathology laboratory and research field of BARI, Gazipur
Pest Management
Diseases, Marigold
The experiment was conducted at the plant pathology laboratory and research field of BARI, Gazipur during the 2018-19 conducted winter seasons. The first experiment was conducted in the laboratory of the Plant Pathology Division, BARI to evaluate the antifungal activities of fungicides. The name of fungicides was Secure 600WG 1g/L(fenamidone +Mancozed group), Score 250EC 2ml/lit (Difenoconazole group), Faja 70 Wp 2g/L (Mancozey45% + Fosetyl AL 25% group) along with a Control. The required amount of all fungicide was added in melted PDA to have a 100 ppm concentration. The PDA with treatments was poured immediately in 90mm sterile Petri dishes @ 20ml per plate and replicated five times. PDA without any treatments was used as a control. Each plate was inoculated with block or suspension (pathogen) of Sclerotinia sclerotiorum. The inoculated plates were incubated at (25+1)0c following Complete Randomized Design (CRD) and redial mycelial growth were recorded after 3, 6 and 9 days of incubation, No of sclerotinia / plate and Percent growth inhibition of pathogen will be calculated by using the following formula by Abdel-Kader, (2012):
PI = (A-B) / A x 100
where A is colony growth of the fungus in control plate
and B is colony growth of the fungus in treated plate.
All data was subjected to analysis of variance (ANOVA) and the mean differences were compared by R software. Differences at P< 0.05 was considered significant.
Field test:
The hybrid variety Inca was shown in 3× 3 m2 plots size. A field experiment was laid out in Split Plot Design, the main plot treatment was T1= Neem oil cake (600 kg/ha), T2= Tobacco dust (600kg/ha) and the sub plot treatment was T1= Secure 600 WG (1g/L), T2= Score 250 EC (2g/L) T3= Faja 70 WP (1g/L), T4= Control with replications three. The first spray was given at first disease appearance. In total, three sprays were applied at 9 days intervals. Assessment of diseases severity for Sclerotinia sclerotiorum was recorded at seven days after the last spray and the percent diseases index was calculated by Rahman and Rahid (2008) as follows
∑ Class rating × Class frequency
PDI = × 100
Total no of flower graded × Maximum rating scale
The plots were inspected regularly to observe the white mold disease symptoms as well as the appearance of white mycelium and sclerotia. Whole plots were rated for the presence or absence of disease (disease incidence) and the percentage of total flower area exhibiting symptoms or signs was determined (disease severity). The severity rating 0 to 5 scale was used, where 0 = non-infected, 1 = Less than 1 % flower area infected, 2 = 1 to 10 % flower area infected, 3 = 11 to 20 % flower area infected, 4 = 21 to 50 % flower area infected , 5 = More than 50 % flower area infected. For sample collection five plants/ plots were selected randomly. Data were recorded on Diseases incidence, Disease reduction over control, Diseases severity, No of infected flowers / plant and No of uninfected flowers / plant. All data was subjected to analysis of variance (ANOVA) and the mean differences were compared by R software. Differences at P< 0.05 was considered significant.
Annual Research Report 2018-19, Plant Pathology Division, BARI, Gazipur
Report/Proceedings