http://localhost:8080/handle/123456789/2648 2026-04-18T17:40:00Z 2026-04-18T17:40:00Z RAHAMAN, MD. ABDUR http://localhost:8080/handle/123456789/4936 2023-07-25T05:24:06Z 2020-01-01T00:00:00Z

STUDY ON LEAF BLIGHT OF GLADIOLUS (BOTRYTIS GLADIOLORUM) IN BANGLADESH AND ITS MANAGEMENT RAHAMAN, MD. ABDUR A set of investigations comprising six experiments were conducted in the Department of Plant Pathology, Sher-e-Bangla Agricultural University, during the consecutive years 2016 to 2020 in Bangladesh. The investigation was aimed to find out the disease incidence and severity of gladiolus leaf blight disease in major gladiolus growing districts in Bangladesh and its management in vitro and in vivo. A survey was conducted in selected gladiolus growing districts in Bangladesh and the data on the disease incidence and disease severity were collected. Leaf blight infected leaves, stems and flowers samples were collected and studied. Survey data revealed that leaf blight incidence in all the districts showed statistically similar result except Bogura and Dhaka. Disease incidence was varied from 18.89% to 32.22%. On the other hand, the highest severity (17.22%) was found in Manikganj district which was statistically similar with Cox’s Bazar (15.56%), Faridpur (13%) and Jashore district (12.33%). The lowest disease severity (5.56%) was found in Gaibandha district. Forty-four (44) isolates of Botrytis gladiolorum were isolated and identified from the sample collected from survey areas. The highest mycelial radial growth of Botrytis gladiolorum (72.00 mm) was recorded from BGCCO3 whereas the lowest (33.00 mm) growth was recorded from BGCCO5 in PDA media at 16 DAI. The radial mycelia average growth rate /day ranged from 2.06 mm to 4.5 mm. Fourteen (14) cultural groups of B. gladiolorum were determined based on cultural characteristics. Among ten fungicides, Contaf 5 EC gave the best results in arresting radial mycelia growth and it was nil (00.00 mm) after 5 DAI in 100 ppm which was statistically similar with indofil 80 WP treated (00.00 mm) plate and the inhibition of growth was 100%. At 15 DAI the growth inhibition (87.34%) was highest in contaf 5 EC treated plate followed by Score 250 EC (78.02%) and Autostin 50 WDG (72.34%) respectively. In 200 ppm Contaf 5 EC showed the best performance against mycelial growth at 15 DAI and gave 100% growth inhibition which was statistically similar to Score 250 EC (100% inhibition) followed by Autostin 50 WDG (83.04) and Folicure 250 EC (82.90%). In 300 ppm Contaf 5 EC showed the best performance at 15 DAI against mycelia growth and showed 100% inhibition which was statistically similar to Score 250 EC (100% inhibition), Autostin 50 WDG, Tilt 250 EC and Folicure 250 EC. Among ten botanicals studied 20% garlic extract showed the best result at 5 DAI and the radial mycelia growth was nil (00.00 mm) which was statistically similar with onion extract and turmeric extract treated plate. At 15 DAI the inhibition of fungal growth was found (73.74%), (71.23%) and (66.90%), respectively with treated by turmeric extract (18.80 mm), garlic extract (20.60 mm) and onion extract (23.70 mm). Among nine organic acids tested at the rate of 1000 ppm Acetic acid gave the best performance and showed (57.02%) inhibition of mycelia growth at 15 DAI followed by Benzoic acid (48.04%) and oxalic acid (41.97%). Three fungicides (Score 250 EC, Contaf 5 EC and Autostin 50 WDG) at the rate of 300 ppm, three botanicals (Turmeric, Garlic and Onion) at the rate of 20% and three organic acids (Acetic acid, Benzoic acid and Oxalic acid) at the rate of 3000 ppm were evaluated in the field against gladiolus leaf blight. At the flowering stage lowest incidence (14.81%) was found in Score 250 EC treated plot which was statistically similar with Contaf 5 EC (14.81%), Autostin 50 WDG (18.51%) and Turmeric extract (20.37%). Disease severity was lowest in Score 250 EC treated plot (8.33%) which was statistically similar with Contaf 5 EC (9.00%), Autostin 50 WDG (10.00%) and Turmeric extract (10.67%). The growth parameters and yield were also found highest in score 250 EC treated plot, which was statistically similar with Contaf 5 EC, Autostin 50 WDG and Turmeric extract treated plot. A Dissertation submitted to the Faculty of Agriculture Sher-e-Bangla Agricultural University, Dhaka in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN PLANT PATHOLOGY

2020-01-01T00:00:00Z KABIR, MD. HUMAYUN http://localhost:8080/handle/123456789/4657 2022-12-01T11:07:47Z 2021-12-01T00:00:00Z

MOLECULAR CHARACTERIZATION OF ALTERNARIA SPECIES AND INTEGRATED MANAGEMENT OF GREY BLIGHT DISEASE OF MUSTARD KABIR, MD. HUMAYUN Mustard (Brassica spp.) is the most important oil seed crop in Bangladesh and the major constraint is grey blight disease which caused significant yield losses. The prime aim of the study was to characterize the Alternaria species on the basis of morpho-molecular variation and integrated management of the grey blight disease. The present study was carried out in combination of six sequential experiments. The experiments were conducted in Molecular Biology and Plant Virology Laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka and Plant Pathology Laboratory, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur. For characterization study, fungal DNA was extracted from the pure culture of Alternaria and PCR amplification was done using the ITS primer which designed to amplify at 700 bp. For the management study to evaluate the effectiveness of selected bio-agent, chemical fungicides, botanicals and their combined effects were assessed. In total 14 treatments including control were considered viz. T 1 = Trichoderma harzianum suspension, T 3 = Autostin 50 WDG, T 4 = Control, T 2 = Rovral 50 WP, T 5 = Dithane M-45, T 6 = Amistar Top 325 SC, T 7 = Neem leaf extract, T 8 = Allamanda leaf extract, T 9 = Lantana leaf extract, T 10 = Datura leaf extract, T 11 = Neem leaf extract+ Rovral, T 12 = Datura leaf extract + Amistar Top, T 13 = Lantana leaf extract + Dithane M- 45 and T 14 = Allamanda leaf extract + Autostin. From the morphological characterization of Alternaria species, it was found that the highest radial mycelial growth (43 mm) was recorded in Manikganj isolate and the lowest (18.13 mm) in Satkhira isolate at 14 DAI and others morphological characters were varied significantly. All Alternaria isolate was found to be pathogenic in nature that confirmed in the pathogenicity test. From the molecular characterization study, the nucleotide sequences of Alternaria isolates were showed 99% similarity with the existing nucleotide sequences and closely related to isolates of Alternaria brassicae, Alternaria brassicicola and Alternaria alternata that globally found in GenBank data based. Among the treatments, there was no radial mycelial growth of Alternaria was recorded in T 4 (Rovral 50 WP), T 6 (Dithane M-45) and T 11 (Neem leaf extract+ Rovral) at all observations. From the results of field management study, it was observed that all the treatments showed significant effect on different assayed parameters. In case of botanicals, the lowest disease incidence (%), disease severity (%), disease severity index (%) and pod infection (%) was found in T 9 treatment (Lantana leaf extract) which was 65.05%, 28.89%, 37.96% at 70 DAS respectively and 13.79%, at 75 DAS. In case of chemicals, the lowest disease incidence (%), disease severity (%), disease severity index (%) and pod infection (%) was found in T 5 treatment (Dithane M-45) which was 55.91%, 22.09%, 32.16% at 70 DAS, respectively and 6.72% at 75 DAS. In case of combined treatments, the lowest disease incidence (%), disease severity (%), disease severity index (%) and pod infection (%) was found in T 13 treatment (Lantana leaf extract + Dithane M45) which was 59.14%, 26.32%, 38.20% at 70 DAS, respectively and 12.30% at75 DAS. From the findings on different parameters studied in both management experiments, Dithane M-45, Lantana leaf extract and their combined treatment could be used in further field trials and then may be recommended for management of grey blight mustard. A Dissertation Submitted to the Faculty of Agriculture Sher-e-Bangla Agricultural University, Dhaka in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN PLANT PATHOLOGY SEMESTER: JULY - DECEMBER, 2021

2021-12-01T00:00:00Z LAILA, LUTFUNNAHER http://localhost:8080/handle/123456789/4074 2022-08-04T08:22:32Z 2019-12-01T00:00:00Z

EVALUATION OF RICE CULTIVARS AGAINST RICE BLAST AND IN VITRO MANAGEMENT OF MAGNAPORTHE ORYZAE LAILA, LUTFUNNAHER A set of investigation comprising four experiments was conducted in the Department of Plant Pathology, Sher-e-Bangla Agricultural University, during three consecutive year 2016, 2017, 2018 from March to June in Bangladesh. The investigation was aimed to find out the pathogenic variability of rice blast pathogen Magnaporthe oryzae, its epidemic nature in rice growing areas in Bangladesh and finally its in vitro management including varietal screening against the disease. For the epidemic nature of rice blast and its pathogenic variability, a survey was conducted in different rice growing regions in Bangladesh from where the disease incidence and disease severity data and subsequently the blast infected leaves and stems samples were collected. Survey data revealed that the highest disease incidence (60%) was found in Bogura district, whereas the lowest (10%) was observed in Dhaka, Sunamgonj, and Moulvi Bazar districts. The highest (5%) disease severity was recorded in the Kishoregonj District, while the lowest (3.33%) was in the Dinajpur District. Twenty-six (26) isolates of Magnaporthe oryzae were isolated and identified from the sample collected from survey areas. The highest mycelial radial growth of M. oryzae (29.67 mm) was recorded for OMA, whereas the lowest (15.00 mm) in PR S DA culture media. In 7 days after culture, the highest redial mycelial (51.50 mm) was recorded from the isolate of PBSL20, while the shortest (32.00 mm) was from the isolate of MNKL12. At 14 days after incubation, the longest redial mycelial growth (85.83 mm) was found from the isolates of DKRP19, while the shortest redial mycelial growth (60.33 mm) was found from the isolates of MBBL09. In case of in vitro management among the 12 fungicides, maximum growth inhibition (100%) of M. oryzae was found in Folicular 250 EC (Tebuconazole-10%), Seltima 100 CS (Pyraclostrobin-10%), Filia 525 SE (Propiconazole-12.5%) + Tricyclazole-40%)) and Difar 300 EC ((Difenoconazole15%) + Propiconazole-15%)), whereas the lowest (0.00%) inhibition was recoded in Autostin 50 WDG. Among 8 botanicals Neem, Alamanda, and Aloe vera were performed best and significantly inhibited radial mycelial growth. In vitro radial mycelial growth of M. oryzae with bio-agent (Trichoderma harzianum) in PDA media trial the radial mycelial growth of M. oryzae was 0.00 mm irrespective of inoculation design. In contrast, the radial mycelial growth of bio-agent Trichoderma harzianum was 41.67 mm, 36.67, and 41.67 mm. In control condition, radial mycelial growth of test fungus and bio-agent was 12.33 mm and 41.67 mm, respectively. Among 17 rice germplasms tested, only two cultivars, Jeera Vog and BRRI dhan33, were found resistant against M. oryzae in the uniform rice blast nursery. Key words: Rice blast, Magnaporthe oryzae, in vitro, fungicide, botanical, bio-agent A Dissertation submitted to the Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN PLANT PATHOLOGY SEMESTER: JULY-DECEMBER, 2019

2019-12-01T00:00:00Z KARIM, ZINNAT http://localhost:8080/handle/123456789/2612 2019-09-26T10:03:52Z 2017-06-01T00:00:00Z

STUDY ON PHENOTYPIC CONVERSION, VIRULENCE AND BIOVAR EXPRESSION OF RALSTONIA SOLANACEARUMCAUSING POTATO WILT AND ITS MANAGEMENT KARIM, ZINNAT ZINNAT KARIM Infected samples from different sources of inoculum viz. plant, soil, seed, weed, other crops, irrigation water etc. were collected from major potato growing districts of Bangladesh viz. Munshiganj, Chandpur, Tangail, Narayanganj, Jamalpur, Domar, Patuakhali, Rangpur, Bogra, Shariatpur, Meherpur, Joypurhat and Dinajpur to investigate the presence of R. solanacearum. Cross cut of plant samples showed bacterial ooze streaming in clear water and browning of the vascular bundle region of seed tuber were observed. Standard methods viz. Kelman’s tetrazolium chloride 0 C and 28 0 C temperature. Again, under the influence of temperature avirulent colony of R. solanacearum showed VBNC state at 10 0 C. In vitro and in vivo performance test with ten bioactive compounds against R. solanacearum were conducted as compared to control, bactericide and farmers practice to design an effective management tool. Propolis C and over 40±2 0 Key words: Bacterial wilt disease, Bangladesh, heterogeneity in virulence and biovar(s A Thesis Submitted to the Faculty of Agriculture, Sher-E-Bangla Agricultural University, Dhaka in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY IN PLANT PATHOLOGY SEMESTER: JANUARY-JUNE, 2017 SHER-E-BANGLA AGRICULTURAL UNIVERSITY DHAKA-1207

2017-06-01T00:00:00Z