Year 2020

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ASSESSMENT OF MOSTLY CULTIVATED BORO RICE VARIETIES AGAINST RICE BLAST CAUSED BY MAGNAPORTHE ORYZAE AND ESTABLISHMENT OF KOCH’S POSTULATE THROUGH PATHOGENESIS
(DEPARTMENT OF PLANT PATHOLOGY, 2020) AKTER, SHAMMY
In Bangladesh last few years, Rice blast caused by fungus, Magnaporthe oryzae played vital role in reducing the yield. In the current study, a field, lab and cup tray experiment was carried out in the Department of Plant Pathology, Sher-e-Bangla Agricultural University (SAU), Dhaka-1207 during the period October, 2018 to May, 2019. The field experiment was conducted in central farm of SAU for the evaluation of the mostly cultivated boro rice varieties viz. BRRI dhan 28, BRRI dhan 29, BRRI dhan 58, BINA dhan 8 and BINA dhan 10, two high yielding varieties viz. BRRI dhan 74 and BRRI dhan 81 and one wild variety against rice blast pathogen. The lab experiment was done in Molecular Biology and Plant Virology Lab for the etiology study of rice blast pathogen. Potato sucrose agar (PSA) media was used to isolate the blast pathogen and identification was done on the basis of cultural and morphological structures of Magnaporthe oryzae. A cup tray experiment was also carried out to establish the Koch’s postulate through pathogenicity test. From the field experiment, it was found that the disease incidence and severity of rice blast was showed significant variants among the tested varieties and ranged from 0.00 to 21.48 and 0.00 to 60.48% respectively. The highest disease incidence and severity was recorded in BRRI dhan 58. There was no disease incidence (0.00%) and severity (0.00%) was found in selected wild variety throughout the growing season. Other varieties showed moderate disease incidence and severity that was statistically not significant each and other. From the study, it was noted that the disease severity of rice blast in tested varieties was showed moderately resistant to susceptible and the selected wild variety showed tolerance/highly resistance to blast pathogen. From the cultural and morphological study of the derived isolate from the field samples, it was evident that the disease was caused by Magnaporthe oryzae, as the isolate produced hyaline, pyriform three celled conidia from leaf sample and media respectively. The etiology of rice blast pathogen was also studied through establishment of the Koch’s postulate. In the study, yield and yield contributing characters of selected boro rice varieties against blast disease was also studied, and it showed statistically non-significant. However from the study it may be concluded that wild cultivar can be alternative of BRRI dhan 28 and BRRI dhan 58, but it needs further more trial. This wild variety can also be used in resistance breeding program to develop the induced resistance system in rice plant.
ASSESSMENT OF VARIETAL PERFORMANCE OF SELECTED TOMATO VARIETIES AGAINST Tomato Yellow Leaf Curl Virus (TYLCV) AND ITS MOLECULAR DETECTION THROUGH PCR
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MD. IBNE-SIAM-JOY
An experiment was conducted in field and laboratory condition under the Department of Plant Pathology of Sher-e-Bangla Agricultural University, Dhaka-1207 during 2018-2020.The field experiment was carried out in a Randomized Complete Block Design (RCBD) with three replications. Genomic DNA extraction and PCR test was done in Molecular Biology and Plant Virology Laboratory following the standard protocol. In this experiment ten selected variety was selected for conducting the experiment. Among the ten selected varieties three varieties; BARI Tomato-5, BARI Tomato-18 & BARI Tomato-19 showed moderately resistant reaction and lower disease severity against the TYLCV. Remaining selected varieties; BARI Tomato-17, BARI Tomato-8, BARI Tomato-9, BARI Tomato-11, BARI Tomato- 14, BARI Tomato-15, BARI Tomato-16 were showed susceptible reactions to highly susceptible and higher disease severity against TYLCV. In case of BARI Tomato-5, BARI Tomato-18 & BARI Tomato-19 whitefly association was not increased with the increase of plant age. But it was noticed that in case of the remaining varieties whitefly association was increasing with the increase of plant age. Different growth parameters yield and yield contributing characters were also studied. Among the selected varieties the maximum number of leaves per plant was obtained in the variety BARI Tomato-11 and minimum was obtained in the variety BARI Tomato-9. The highest number of branches per plant was recorded in the variety BARI Tomato-11 and the lowest was recorded in the variety BARI Tomato-14. The maximum number of flowers was also obtained from BARI Tomato-11 and the minimum was observed from BARI Tomato-17. The maximum number of fruits was obtained from BARI Tomato-11 and the minimum was obtained from BARI Tomato-18. The maximum individual fruit weight was obtained from BARI Tomato-17 and minimum fruit weight was obtained from BARI Tomato-11. The highest yield per plant was obtained from BARI Tomato-17 and the lowest yield per plant was obtained from BARI Tomato-5. From molecular study through PCR test, it was revealed that results obtained on the basis of biological properties that was almost similar to PCR analyses to detect the TYLCV. Among the selected varieties, seven varieties; BARI Tomato-8, BARI Tomato-9, BARI Tomato-11, BARI Tomato-14, BARI Tomato-15, BARI Tomato-16 & BARI Tomato-17 gave the positive results in PCR test and shown sharp band at 520 bp fragment. Other varieties; BARI Tomato-5, BARI Tomato-18 and BARI Tomato-19 gave negative result in PCR test. For the molecular detection of Tomato Yellow Leaf Curl (TYLCV), PCR is the most reliable modern technique because it is simple, very specific and highly robust.
BANANA VALUE CHAIN ANALYSIS FOR DETECTING FACTORS RESPONSIBLE TO POST-HARVEST DISEASES
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MAHMUD, MD. AL SABBIR
A survey was conducted to analyze Banana value chain and to determine postharvest problems at farmer and traders level. The survey was conducted during the periods of August, 2019 to February, 2020 in the Dinajpur district and three markets as well as 40 retailer shops of Dhaka city. Value chain was analyzed by the combination of qualitative and quantitative questionnaire methods that included primary survey focusses group discussions, answering questionnaire and informal interviews. Value chain analysis clearly revealed that Banana growing areas are increasing every year gradually and most of the orchards have 250-700 plants and the popular Banana varieties were Amrita Shagor, Sabri and Champa. Farmers used manure and fertilizers in Banana orchards in regular basis. All of the farmers were used to different type activities without maintaining any hygiene to harvest Bananas. Van and Nosimon are the most common transport for short distance carrying and Truck for long distant carrying. The common marketing channel is Grower> Paikar> Bepari> Retailer >Consumer. Lack of modern storage and transport, processing industries, high margin traders, no use of any packaging system, transport and production cost, and uncertainty of market price were also reported as difficulties in value chain of Bananas. Among intermediaries, the highest loss was recorded for Retailer (23.58%) followed by Piker (1.31%) and Bepari (5.85%). The highest incidence disease was observed for anthracnose 18.73% and crown rot 8.89% during August to October. The lowest incidence was observed for anthracnose 2.58% and crown rot 2.08% during November to February. The postharvest loss of Banana was found 37.21% in total.
CONTAMINANTS AND YIELD OF DIFFERENT STRAINS OF MAPLE OYSTER MUSHROOM (Pleurotus cystidiosus) IN SELECTED SUBSTRATES
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MOU, TANIA AKTAR
The experiment was carried out at the mushroom culture house of Mushroom Development Institute, Saver, Dhaka and central laboratory of SAU during the period from October 2019 to March 2020. The experiment was conducted to compare different strains of maple oyster mushroom on contaminants, growth and yield contributing characters. Seven strains of Pleurotus cystidiosus, viz. Pcys-1, Pcys-2, Pcys-3, Pcys-4, Pcys-5, Pcys-6 and Pcys-7 and three different substrates S 1 (Saw dust), S 2 (Rice straw), S (Saw dust + Rice straw) were used in this experiment. The experiment was laid out in Completely Randomized Design (CRD) with four replications. Trichoderma sp, Alternaria sp and Aspergillus niger were identified as contaminants, where green mold was detected as the major one. The highest contamination incidence (100%) was observed in S 1 P 6 , S 1 P 7 and S 3 P 2 3 , whereas the lowest incidence (60%) was recorded from S 1 P . The lowest days (7 days) required for mycelium running on spawn was found in S 1 1 P 1 , S 1 P 2 , S 1 P 3 , S 1 P 4 and S 1 P . No mycelium running was observed in Pcys-6 and Pcys-7. The highest biological yield (98.50 g), economic yield (95.75 g) and biological efficiency (53.25%) was found from S 2 P 1 5 , whereas the lowest biological yield (65.25g) was found from S . The highest diameter (7.13 cm) of pileus was recorded from S 3 P whereas the lowest diameter (4.13 cm) of pileus was found in S 1 P . Rice straw showed better performance followed by saw dust and combination of the both rice straw and saw dust during cultivation. 2 Key words: Pcys, Substrate, Biological yield, Economic yield, Biological Efficiency
CULTURAL AND MOLECULAR CHARACTERIZATION OF Fusarium ISOLATES CAUSING WILT DISEASE OF SOLANACEOUS VEGETABLES
(DEPARTMENT OF PLANT PATHOLOGY, 2020) NITOL, RAKIBUL HASAN
Fusarium spp. represent one of the noxious groups of plant pathogen causing wilt disease of many economically important crops. Due to presence of remarkable variability among its isolates, management options against this pathogen are quite difficult. Therefore, the present experiment was conducted to study the variability of different isolates of Fusarium spp. collected from major vegetable growing regions of Bangladesh. Those isolates varied morphologically with cottony white, cottony white with brownish center, cottony pinkish white, pinkish white, whitish purple, purplish and creamy colored colony where the colony shape was regular, regular with concentric ring to irregular. Margin of the colony were entire, wavy, curled, filiform and undulated with crateriform, fluffy, flat and convex colony texture. Mycelial growth rate of the isolates was between 2.00−10.32 mm day -1 where, the isolates DSAUB and JhKT exhibited the highest and the lowest growth, respectively. The isolates were also clustered into three groups based on colony diameter viz. fast growing, moderate growing and slow growing fungi. The variation of conidia production was between 2.66×10 6 −12.33 × 10 6 ml -1 suspension with sporulation time 3.33−7.33 days. Molecular identification of Fusarium spp. isolates was preformed through amplification of fungal DNA at ITS region, sequencing the DNA molecules and analyzing the sequence in “NCBI-BLAST” database and then six isolates viz. DSAUT, MMsB, MMsC, BGT, BGP and JJHB were identified as Fusarium oxysporum and another three isolates i.e. GBARIB, MeGP and PBC were identified as F. fujikuroi, F. solani and F. commune, respectively. Phylogenetic trees of the queried isolates in relation to globally reported Fusarium isolates revealed that there was a strong ancestral relationship among the native isolates and the respective globally reported isolates of Fusarium spp. Virulence level of the isolates also varied significantly. The isolates were grouped as highly virulent (HV), virulent (V), moderately virulent (MV) and avirulent (AV) pathogen based on disease incidence. The overall results demonstrated the existence of cultural, morphological, pathogenic and molecular variation of Fusarium spp. isolates in native environment.
ECO-FRIENDLY APPROACHES FOR THE MANAGEMENT OF COLLAR ROT OF MUNGBEAN CAUSED BY Sclerotium rolfsii
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MOKARROMA, SANZIDA
Mungbean is a highly nutritive and protein rich crop. Collar rot caused by Sclerotium rolfsii is the major disease of mungbean causes a considerable yield loss in Bangladesh. Frequent use of chemical fungicides to control the disease is causing serious environmental hazards. The in vitro experiment was conducted at Plant Pathology Laboratory located in Wazed Miah Central Laboratory and field experiment was conducted in Central farm of Sher-e-Bangla Agricultural University during January, 19−January, 2020. The experiment was conducted to isolate, identify and to develop eco-friendly management of Sclerotium rolfsii. The isolated organism causing collar rot of mungbean identified as Sclerotium rolfsii based on its key characteristics (CMI Description No. 410). For management of the disease, a bioagent (Trichoderma harzianum), two botanicals (allamanda and neem leaf extract), three soil amendments (mustard oil cake, Krishibid organic fertilizer, virmicompost), two fungicides (Autostin 50WDG and Goldton 50WP) were evaluated in laboratory as well as in field and integration of those components was done in field. Seed treatment with Trichoderma harzianum and soil drenching with allamanda leaf extract was found most effective in reducing 91.31% disease incidence and increasing 183.01% yield over control. Soil drenching with Trichoderma harzianum suspension and seed treatment with Autostin 50 WDG reduced disease incidence 91.05% and increased yield 169.81% over control. Trichoderma harzianum suspension + Mustard oil cake + Krishibid organic manure + vermicompost, Trichoderma harzianum suspension + Goldton 50 WP, Trichoderma harzianum suspension, Krishibid organic fertilizer, vermicompst, mustard oil cake was found effective and increased 156.60%, 118.87%, 116.87%, 113.01%, 88.67%, 88.6%, 37.7% yield over control, respectively. The highest BCR value was recorded in combined application of Trichoderma harzianum and allamanda leaf extract.
ECO-FRIENDLY APPROACHES FOR THE MANAGEMENT OF FRUIT ROT OF EGGPLANT CAUSED BY Phomopsis vexans FOR SEED PRODUCTION
(DEPARTMENT OF PLANT PATHOLOGY, 2020) NOOR, ASIF
Phomopsis fruit rot is a major constraint of quality seed production of eggplant in Bangladesh. The in vitro experiments were conducted in the M.S. Laboratory of the Department of Plant Pathology and the field experiment was conducted in the Central Farm, Sher-e-Bangla Agricultural University, Dhaka-1207 during October 2018 to May 2019. A set of experimentation strategically designed to select the highest disease mitigating treatments for employing in ecofriendly management approaches against Phomopsis vexans for seed production of eggplant. The isolated organism causing fruit rot of eggplant was identified as Phomopsis vexans based on its key characteristics (CMI Description no. 338). For the management of the disease, a bioagent (Trichoderma harzianum), three fungicides viz. Companion, Autostin 50WDG and Tilt 250EC, four plant extracts viz. Allamanda leaf extract, Garlic clove extract, Turmeric rhizome extract and Onion bulb extract, and Krishibid Organic Fertilizer were evaluated in the experiment. The foliar spray of Trichoderma harzianum (“Biotech Care Trichoderma Suspension”) was found most effective in controlling the incidence and severity of fruit rot caused by Phomopsis vexans, increasing the fruit yield by 142.05% and seed yield by 146.84% compared to control. Seed germination of harvested seeds increased by 88.41% over control. Soil amendment with Krishibid Organic Fertilizer combined with Autostin 50WDG spraying was also found effective in increasing the fruit yield by 137.39%, seed yield by 142.54% and seed germination by 93.56% compared to control. Among the plant extracts, Garlic bulb extract and Turmeric rhizome extract were found most effective in increasing the fruit yield by 112.16%, 96.93%; seed yield by 112.15%, 100.05%, respectively over control.
EFFECT OF DIFFERENT SUBSTRATES AND MOTHER CULTURES ON YIELD AND YIELD PARAMETERS OF OYSTER MUSHROOM (PLEUROTUS OSTREATUS)
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MUYEED, MUBASSHIRA
This study was conducted to determine the effects of different substrates and mother culture materials on yield and yield parameters of oyster mushroom (Pleurotus ostreatus) in the Laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University and Mushroom Research Institute, Savar, Dhaka. Three substrates namely sawdust, rice straw and sawdust + rice straw (1:1) and three mother cultures namely rice, maize and sawdust were tested for their efficacy in oyster mushroom production. Among the substrates the highest length of the stipe, thickness of pileus and biological yield were found in rice straw (23.27 mm, 5.60 mm and 44.40 g/packet, respectively). The highest diameter of stipe and diameter of pileus were measured in sawdust + rice straw (1:1) (9.90 mm and 72.90 mm, respectively). The highest number of fruiting body/packet was counted in sawdust (6.67). Among the mother cultures the highest length of the stipe, number of fruiting body/packet and biological yield were found in sawdust mother spawn (23.27 mm, 6.67 and 45.47 g/packet, respectively). The highest diameter of stipe and thickness of pileus were observed in maize mother spawn (9.90 mm and 5.60 mm, respectively). The highest diameter of pileus was measured in rice mother spawn (67.57mm). In the combined effect of substrates and mother spawn materials the highest biological yield was recorded in sawdust mother spawn (50.80 g/packet) in which the substrate material was rice straw. The result revealed the good growth performance of oyster mushroom in terms of substrates and mother spawn. So, rice straw substrate and sawdust mother spawn can be recommended for the cultivation of oyster mushroom (Pleurotus ostreatus) among the tested substrates and mother spawn culture materials.
EFFECT OF DIFFERENT TYPES AND AMOUNT OF SUBSTRATES ON CONTAMINATION GROWTH AND YIELD OF PINK OYSTER MUSHROOM (Pleurotus djamor)
(DEPARTMENT OF PLANT PATHOLOGY, 2020) PERVIN, SURAYA
An experiment was carried out to find out the effect of different substrates and spawn packet sizes on the growth and yield of pink oyster mushroom (Pleurotus djamor) and to estimate the rate of contamination of spawn packets. Among the selected 5 substrates namely rice straw, mustard straw, saw dust, sugarcane bagasse and waste paper, the minimum days (15.43 days) for mycelium running was recorded in mustard straw whereas the maximum days (18.93 days) required for mycelium running was recorded in waste paper. Number of effective fruiting bodies was maximum at rice straw (21.43) and weight of individual fruiting body was highest at waste paper (4.88g). The highest biological yield (83.36g) and biological efficiency (76.76%) was recorded in rice straw, whereas the lowest biological yield (49.14g) and biological efficiency (43.95%) was recorded in waste paper substrate. In case of 250g and 500g spawn packet size, days required for mycelium running, days required for primordia formation and total harvest days was minimum in 250g substrate packet. The number of effective fruiting body, weight of individual fruiting body was maximum in 500g spawn packet. Maximum biological yield (79.44g) was recorded in 500g spawn packet whereas the maximum biological efficiency (65.90%) was recorded in 250g spawn packet. Mustard straw at 250g substrate/packet required minimum time (14.43 days) for mycelium running and primordial formation (5.43 days) whereas waste paper at 500g substrate/packet required maximum time for mycelium running (19.43 days) which was statistically similar with sugarcane bagasse at 500g substrate/packet (19.29 days). Total harvesting day was highest (49.57 days) both in waste paper and saw dust @ 500g substrate/packet. Rice straw at 500g spawn packet gave maximum biological yield (103.14g). whereas rice straw at 250g spawn packet gave maximum biological efficiency (84.76%) followed by rice straw at 500g spawn packet (68.76%) and saw dust 250g spawn packet (68.75%). Total 3 fungi namely Trichoderma harzianum, penicillium sp. and Aspergillus niger were isolated and identified. Percent contamination of fungi gradually increased from 1 st harvesting to 3 rd harvesting stage. Maximum severity of contamination 10.71% was observed in sugarcane bagasse at 500g spawn packet during 3 rd harvest.
EFFECT OF ORGANIC AMENDMENTS AND CARBENDAZIM ON NODULATION AND CONTROLLING OF FOOT AND ROOT ROT OF LENTIL
(DEPARTMENT OF PLANT PATHOLOGY, 2020) AKTER, MST. RUMI
The present study was conducted for the effect of organic amendments and Carbendazim on nodulation and controlling of foot and root rot of lentil in in- vitro and in-vivo conditions at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from November 2018 to May 2019. The experiment consists of 8 treatments such as T 0 = Control, T 1 = Poultry manure, T 2 = Cow dung, T 3 = Spent mushroom compost, T 4 = Carbendazim 50WP, T 5 = Spent mushroom compost + poultry manure, T 6 = Spent mushroom compost + cow dung, T 7 = Spent mushroom compost + Carbendazim 50WP. BARI masur 4 variety was used in this experiment. In in-vitro condition, the reduction of mycelium growth was varied from 12.22% to 36.48% and the highest reduction was recorded in T 7 . In field experiment, the lowest disease incidence (10.57%) was recorded in T 7 and the highest disease incidence in control (47.30%). The highest percent reduction of disease incidence over control was found in T 7 (77.65%) followed by T 6 (75.58%). In all cases of yield contributing characters such as number of nodules/plant, pods/plant, seeds/pod, 1000-seed weight and grain yield increased by the combination of spent mushroom compost with cow dung. Significantly the highest yield (1486.70 kg/ha) was found under the treatment T 6 followed by T 7 (1425.70 kg/ha) and T 5 (1403.80 kg/ha), respectively. Carbendazim alone and in combination of spent mushroom compost with Carbendazim and cow dung were statistically similar in respect of performance against Foot and root rot of lentil.
EFFECT OF SOWING TIMES AND ORGANIC SOIL AMENDMENTS ON FOOT AND ROOT ROT DISEASE OF LENTIL CAUSED BY SCLEROTIUM ROLFSII
(DEPARTMENT OF PLANT PATHOLOGY, 2020) SARKER, TONUSHRI
In vitro and in vivo experiments were conducted to evaluate the effect of sowing times and organic soil amendments for the management of foot and root rot of lentil caused by Sclerotium rolfsii at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from October 2019 to March 2020. Six different sowing times viz. 25 October, 5 November, 15 November, 25 November, 5 December and 15 December and nine organic soil amendments viz. poultry refuse, mustard oil cake, neem oil cake, vermicompost, cowdung, trichocompost, biochar, sawdust and ash were assessed against the disease. Susceptible variety BARI Masur-1 was used in this experiment. In pot experiments, the lowest disease incidence was recorded in seed sowing on 15 December (15.22%) at 60 days after inoculation (DAI) where the highest disease incidence was recorded in seed sowing on 25 October (49.67%) at same DAI. In case of soil amendment, the lowest disease incidence was recorded in Trichocompost (8.96%) applied pot where the highest incidence was in control (57.65%) pot at 60 DAI. In all cases, growth parameters viz. germination (%), plant height (cm), no. of branch, vigor index and other yield contributing characters were the highest in seed sowing on 15 December and in Trichocompost treated pot. In field experiment, Trichocompost showed the best result with lowest disease incidence (11.11%) and the highest yield (170.11 g/m 2 ). However, the highest disease incidence (58.89%) with the lowest yield (74.44 g/m 2 ) were recorded in control plot. From the above findings, pre-sowing soil application with Trichocompost with late seed sowing after first week of December is recommended to manage foot and root rot of lentil disease.
EFFECT OF TIME OF SOWING ON DISEASE INCIDENCE OF OKRA YELLOW VEIN MOSAIC VIRUS (OYVMV) AND ITS MANAGEMENT THROUGH SELECTED INSECTICIDES AND LIGHT REFLECTING COLORED MULCHES
(DEPARTMENT OF PLANT PATHOLOGY, 2020) JITU, SURAIYA
A field experiment was conducted at the central farm of Sher-e-Bangla Agricultural University, Dhaka-1207, during March to August, 2018. The aim of the study was to investigate the time sowing effect on disease incidence of Okra Yellow Vein Mosaic Virus (OYVMV) in selected okra variety, and to evaluate the effect of light reflecting colored mulches and only one time spraying with selected insecticides to control the insect vector whitefly (Bemisia tabaci). The experiment was carried out in three blocks layouted with RCBD comprising three different sowing times and eight treatments viz. T (control/no spray), T 1 (1 time spray with imitaf), T 2 (1 time spray with protect), T (1 time spray with tiddo plus), T 4 (1 time spray with terbine), T (light reflecting silver color mulch),T 6 (light reflecting red color mulch) and T 7 5 (light reflecting black color mulch) with three replications. The mulches were used before sowing and insecticides were sprayed at 30 DAS. It was observed that among the sowing time, the lowest disease incidence (22.56 %) was found in first sowing (15 th March) and the highest disease incidence (59.00%) was recorded in third sowing (15 th April) at 80 DAS. Among the light reflecting colored mulches, the lowest disease incidence (11.48%) was recorded in the plots which mulched with red color mulch (T ). Among the insecticides, the lowest disease incidence (30.17%) was recorded in plots that was sprayed with terbine (one time).Yield and yield contributing characters, morphological and physiological features of okra plant that changes due to disease infection which cause damages in okra production and reduce the fruit quality as well as market value was also the part of this study. Yield and yield contributing characters showed significant variance among the three different sowing times and selected treatments. The highest yield per plant (0.73 kg) and plot (3.88 kg) was obtained in first sowing. Among the light reflecting mulches, the highest yield per plant (0.92 kg) and plot (4.85 kg) was obtained in the plots that covered with red colored mulch (T 6 6 ). Among the selected insecticides, the highest yield per plant (0.82 kg) and plot (3.18 kg) was obtained in the plots that sprayed with terbine (one time). Among different light reflecting colored mulches and insecticides, the highest plant height (95.86 cm and 95.35 cm) was found in red color mulched plots (T ) and in the plots that was sprayed with terbine (one time) respectively. In the relationship study, it was noticed that the yield and plant height was showed negative relationship with disease incidence. However, considering the all measuring parameters, maintaining sowing time with combining the treatments; spraying with terbine (one time) and used red color mulch may be recommended as good management approaches that will give higher okra production and lower disease incidence of Okra Yellow Vein Mosaic Virus (OYVMV).
EFFICACY OF SELECTED MODERN PHYTO- CHEMICALS AND Trichoderma harzianum AGAINST THE PATHOGEN OF SCLEROTIUM ROOT ROT DISEASE RESPONSIBLE FOR SUGARBEET DECLINE
(DEPARTMENT OF PLANT PATHOLOGY, 2020) A.K.M. ARIF-UZ-ZAMAN
A field experiment on management of sclerotium root rot disease of sugarbeet was conducted in the central farm of Sher-e-Bangla Agricultural University, Dhaka during November, 2019 to March, 2020. The prime aim of the study was to manage the sclerotium root rot disease of sugarbeet using seven modern phyto- chemicals and bio- agent, Trichoderma harzianum. BSRI released tropical sugarbeet line HI 0044 was used as a planting material and seven modern phyto-chemicals viz., Amister Top 325 SC, Acibin, Tilt 250 EC, Ridomil Gold, Dithane M-45, Cabrio Top, Autostin were used in the experiment as a codified treatments. The sugarbeet was grown for sugar production and natural inoculums were relied upon for the infection of sclerotium root rot. Growth parameters, yield attributes and physiological features were significantly affected by the application of selected modern phyto-chemicals and bio- agent. Percent disease incidence and severity of sclerotium root rot was varied among the treatments. The lowest disease incidence (16.67, 13.89 and 16.67%) was found in Amister Top 325 SC, Acibin and Tilt 250 EC treated plots. The highest disease incidence (56.94%) was found in control treatment. The lowest disease severity (4.63, 4.63 and 5.40%) was found in Amister Top 325 SC, Acibin and Tilt 250 EC treated plots. The highest disease severity (14.20, 13.43 and 11.57%) was found in control treatment, Autostin and Dithane M-45 treated plots. Although the Acibin and Tilt 250 EC showed the better performance regarding the percent disease incidence and severity, but other considering parameters were not found at satisfactory level in Acibin and Tilt 250 EC treated plots due to the chemical effects. Plants were severely affected and showed the stunted and shrinked symptoms. The highest individual beet diameter, weight and yield per plot was obtained in Amister Top 325 SC, Dithane M-45, Cabrio Top and Autostin treated plots (41 cm, 1.02 kg, 24.40 kg; 32.28 cm, 0.78 kg, 18.80 kg; 33.38 cm, 0.85 kg, 20.40 kg and 32.58 cm, 0.85 kg, 20.40 kg respectively). The lowest individual beet diameter (19.75 cm), weight (0.51 kg) and yield per plot (12.16 kg) was obtained in control treatment. The highest brix (%) and sucrose/pol (%) was also measured in Amister Top 325 SC, Dithane M-45 and Cabrio Top treated plots (17.8 %, 12.7%; 16.9%, 12.62% and 16.9%, 12.62% respectively). The lowest brix (11.5%) and sucrose/pol (6.53%) was obtained in control treatment. However, from the findings of the study, it may be concluded that among the selected phyto- chemicals, Amister Top 325 SC and Cabrio Top showed the promising performance for management of sclerotium root rot disease of sugarbeet and gave better yield and yield attributes. On the other hand, bio- agent Trichoderma harzianum showed non-satisfactory results regarding the all considering parameters.
EFFICACY OF SOME PLANT EXTRACTS IN CONTROLLING LEAF BLIGHT OF SUNFLOWER
(DEPARTMENT OF PLANT PATHOLOGY, 2020) HAIDAR, MD. ALI
The experiment was conducted in Central MS laboratory and Central Farm of Sher-e-Bangla Agricultural University, Dhaka-1207 during November 2019 to May 2020 to evaluate the efficacy of some plant extracts in controlling leaf blight of sunflower variety BARI Surjamukhi-2. The causal organism isolated from infected leaf of sunflower and identified as Alternaria alternata by tissue planting method. The field experiment was laid out in randomized complete block design (RCBD) with three replications. The treatments consisted of plots sprayed with T 1 =Control, T 2 =Neem leaf extracts, T 3 =Garlic bulb extracts, T 4 =Mint leaf extracts, T 5 =Allamanda leaf extracts, T 6 =Papaya leaf extracts and T 7 =Mahogany leaf extracts. Concentration of all plant extracts was 1:3 w/v. Data were collected on disease incidence, percent disease index (PDI), plant height, number of leaves per plant, stem girth, head diameter, number of seeds per head, 1000 seeds weight and yield. The lowest disease incidence (43.32%) with maximum reduction (45.64%) of PDI over control was recorded in garlic bulb extracts (T 3 ) at 75 DAS. Garlic bulb extracts (T 3 ) treated plots gave better response in all growth, yield and yield contributing parameters viz., tallest plant (132.4 cm), maximum number of leaves (28) per plant, thickest plant (5.47 cm), maximum head diameter (17.78 cm), highest number of seeds (523) per head, 1000 seeds weight (57.46 g) and yield (778.87 g/plot). The maximum yield increased (63.39%) over control was also recorded in garlic bulb extracts (T 3 ) followed by papaya leaf extracts (T 6 ) and neem leaf extracts (T 2 ). In this study it was found that spray with garlic bulb extracts (T 3 ) showed most effective in controlling Alternaria leaf blight incidence, severity with increasing yield of sunflower.
EVALUATION OF COMPATIBLE BIO-AGENTS AND SELECTED BOTANICALS AGAINST RHIZOME ROT DISEASE OF GINGER
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MOURY, SHARMIN MURSHIDA
A pot and lab experiments were conducted in Bio-agents laboratory and the net house of The Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh during the period from July,2019 to June, 2020. The study was carried out to evaluate the efficacy of selected compatible bio-agent viz. Verticillium lecanii (T 1 iii ), Beauveria bassiana (T 2) , Metarhizium anisopliae (T 3 ), Trichoderma viride (T 4 ) and botanicals viz.Tea wastage (T 5 ), Neem leaves extract (T 6 ), Allamanda leaves extract (T 7 ) against the pathogen of rhizome rot disease responsible for ginger decline. The selected bio-agents were applied as a bio-fortified materials. In the pot bio-agents were bio-fortified with the selected substrates; cow dung, mustard oil cake, poultry manure, dust and wheat grain. Data on disease incidence and disease severity was recorded at 50, 70 and 90 Days After Planting (DAP). Among the selected bio-agents the lowest disease incidence and severity was found in T 3 (Metarhizium anisopliae) and the highest in T 1 (Verticillium lecanii). Among the selected botanicals the lowest disease incidence and severity was found in T 5 (Tea wastage) and the highest was found in T 7 (Allamanda leaf extract). No disease was found in T 6 (Neem extract) treatment up to harvesting. The selected treatments were also gave the promising performance in inhibition of radial mycelial growth of Fusarium oxysporum over untreated control. From the in-vitro management study it was found that Trichoderma viride (T 4 ) and Metarhizium anisopliae (T 3 ) gave the better performance in inhibition of radial mycelial growth. Among the botanicals, neem extract gave the promising performance in inhibition of radial mycelial growth. However, from the present study it may be concluded that Metarhizium anisopliae, Trichoderma viride and Neem leaf extract can be used for management of rhizome rot disease of ginger.
EVALUATION OF RESIDENT Trichoderma isolates AGAINST Sclerotium rolfsii CAUSING DAMPING OFF OF MUNG BEAN SEEDLINGS
(DEPARTMENT OF PLANT PATHOLOGY, 2020) MD. SAJEDUZZAMAN
An investigation was carried out to find out the most effective native Trichoderma isolate against Sclerotium rolfsii causing damping off disease of mung bean seedlings. The experiments were carried out at Mycology Laboratory and Net house of Plant Pathology Department, Sher-e-Bangla Agricultural University, Dhaka, during June 2019 - July 2020. All together 13 Trichoderma isolates collected from seven different districts in Bangladesh were explored in the investigation. The isolate JaGot.T was found to be promising in respect of mycelial growth, sporulation and antagonistic effect on Sclerotium rolfsii. The isolate JaGot.T was recorded as the fastest growing antagonistic fungus that covered 89.33 mm of the culture plate by 3 days. The 2 nd highest (86.00mm) and the 3 rd highest (85.333mm) mycelial growth rate was recorded in case of isolate GaJoy.T and GaJoy.T, respectively. The isolate JaGot.T and GaJoy.B were found to sporulate within 2 days producing 6.8433×10 4 and 6.0767×10 4 spores/mm 2 , respectively. JaGot.T inhibited 50.35% growth of S. rolfsii followed by CuDeb.B (44.17%) and GaJoy.B (44.05 %) in dual culture method. The resident Trichoderma isolate JaGot.T showed better performance against Sclerotium rolfsii causing damping off of mung bean next to Autostin and formulated Trichoderma based biopesticide ‘Bioderma’. JaGot.T yielded 76.66% seedling emergence which was statistically similar to ‘Bioderma’ (76.66%) and Autostin (78.0%). The lowest pre-emergence damping off (1.34%) and post-emergence damping off (5.367%) were recorded in case of resident Trichoderma isolate JaGot.T. The Trichoderma isolate JaGot.T also showed better performance in increasing dry matter, shoot length, root length and seedling vigor index of mung bean. The highest seedling vigor index was recorded in case of isolate JaGot.T (2336.88) which was statistically similar to Autostin and Bioderma. The isolate JaGot.T was noted as the best resident isolate of Trichoderma against Sclerotium rolfsii causing damping off of mung bean seedlings among the isolates tested.
EVALUATION OF SELECTED BOTANICALS EXTRACT AND BAU- BIOFUNGICIDE AGAINST CERCOSPORA LEAF SPOT OF LETTUCE
(DEPARTMENT OF PLANT PATHOLOGY, 2020) ALI, MD. YUNUS
The study was conducted to evaluate selected botanicals and BAU- biofungicide against Cercospora leaf spot of lettuce in the Central Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during October, 2019 to February, 2020. Seven botanicals namely Allamanda leaf extract (1:3 w/v), Garlic clove extract (1:3 w/v), Neem leaf extract (1:3 w/v), Onion bulb extract (1:3 w/v), Lantana leaf extract (1:3 w/v), Turmeric rhizome extract (1:3 w/v), Mint leaf extract (1:3 w/v) and BAU- biofungicide (1ml/L) were applied including a control. At different days after transplanting (DAT), BAU- biofungicide and all botanicals significantly showed the minimum disease severity (1.17%), minimum plant disease incidence (15%) with increased yield (47.82%) of lettuce. However, the highest disease reduction with maximum yield and yield components were recorded in BAU- biofungicide applied plot followed by Neem leaf extract and Allamanda leaf extract. The BAU- biofungicide most effective against Cercospora leaf spot of lettuce compare to other treatment used in this experiment.
EVALUATION OF SELECTED VARIETIES OF INDIAN SPINACH (BASELLA ALBA L.) AGAINST CERCOSPORA LEAF SPOT AND ITS MANAGEMENT
(DEPARTMENT OF PLANT PATHOLOGY, 2020) OSHIN, SADIA KADER
Consequently, two experiments were conducted in the experimental field of Sher-eBangla Agricultural University, Sher-e-Bangla Nagar, Dhaka to evaluate selected varieties of Indian spinach (Basella Alba L.) against Cercospora leaf spot and to manage the disease using bio-pesticides and selected botanicals in field condition. The 1 st experiment was conducted during the period of April to June, 2018. Three varieties of Indian spinach namely BARI-1, BARI-2 and one local were selected to conduct the experiment and the experiment was designed at Randomized Complete Block Design (RCBD) with twelve replications. During evaluation, at early, mid and late growth stage, the lowest disease incidence (35.25%, 36.92% and 41.95%, respectively) was observed in BARI-2 variety, whereas the highest (59.36%, 64.49% and (71.37%) in local variety of Indian spinach. Similarly, the lowest disease severity (21.60%, 25.85% and 34.85%, respectively) was observed in BARI-2 variety, whereas the highest (45.25%, 52.45% and 62.50%, respectively) in local variety. The highest yield (23.79 t/ha) was recorded in BARI-2 variety, whereas the lowest yield (19.48 t/ha) in local variety. Based on morphological characteristics, the causal organism was identified as Cercospora beticola in CDA media in laboratory. The 2 ii nd experiment was conducted during the period of February to April, 2019 and one local variety was used as planting material. The experiment comprised to manage the Cercospora leaf spot disease using one bio-fungicide and five botanicals. The treatment combinations were- T 0 = Untreated control (without any treatment); T 1 = Seed treated with BAU-biofungicide followed by Allamonda leaf extract and spray at 7 days interval; T 2 = Seed treated with BAUbiofungicide followed by Neem leaf extract and spray at 7 days interval; T 3 = Seed treated with BAU-biofungicide followed by Mustard oil cake and spray at 7 days interval; T 4 = Seed treated with BAU-biofungicide followed by Garlic and spray at 7 days interval; T 5 = Seed treated with BAU biofungicide followed by Biskatali leaf extract and spray at 7 days interval and T 6 = Seed treated with Allamonda leaf extract followed by Neem leaf extract and spray at 7 days interval. The single factor experiment was designed in RCBD with three replications. At early, mid and late growth stage, the lowest disease incidence (3.38%, 4.74% and 5.24%, respectively) was observed in T 2 , while the highest (57.31%, 64.10% and 71.31%, respectively) in T 0 treatment. The lowest disease severity (3.18%, 3.95% and 4.65%, respectively) was observed in T 2 , while the highest (44.86%, 53.11% and 61.56%, respectively) in T 0 treatment at same growth stage. The highest yield (23.09 t/ha) was observed in T 2 and the lowest (19.66 t/ha) in T 0 treatment. Findings of the experiments revealed that BARI 2 showed best performance among all parameters whereas local variety was more susceptible to Cercospora leaf spot diseases and BAU-biofungicide followed by Neem leaf extract and spray at 7 days interval gave better results compare to the other control measures of the study.
EVALUATION OF TRICHODERMA BASED COMMERCIAL BIO-FUNGICIDES IN CONTROLLING FOOT AND ROOT ROT DISEASE OF LENTIL CAUSED BY SCLEROTIUM ROLFSIIEVALUATION OF TRICHODERMA BASED COMMERCIAL BIO-FUNGICIDES IN CONTROLLING FOOT AND ROOT ROT DISEASE OF LENTIL CAUSED BY SCLEROTIUM ROLFSII
(DEPARTMENT OF PLANT PATHOLOGY, 2020) RAKHI, SURAIYA AKHTAR
Four experiments were conducted to evaluate commercial bio-fungicides for the management of foot and root rot disease of lentil at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during November 2019 to April 2020 following CRD and RCBD design with 3 replications for in vitro and in vivo experiments, respectively. Susceptible variety BARI Masur -1 (Utfala) was used in this experiment. Nine Trichoderma based commercial bio-fungicides viz. G-derma (powder), Bio-derma (powder), Decoprima, Recharge, Bio-derma (peat soil), G-derma (LDS), Terrabio, Decohumate, Ttricost and two chemicals viz. Formaldehyde and Autostin were assessed in this study. In pot experiment, seed treatment with bio-fungicides was done and the lowest disease incidence (6.48%) was recorded from T (Tricost) and the highest disease incidence (54.91%) was observed from T viii 0 5 (Control). Significantly the highest yield /pot (12.55 g) was found in T (Tricost) treatment. In another pot experiment, soil treatment with bio-fungicides was done and the lowest disease incidence (4.84%) was recorded from T 5 5 (Bio-derma - peat soil) and the highest disease incidence (53.29%) was observed from T 0 (Control). Significantly the highest yield /pot (16.83 g) was found in T (Bioderma- Peat soil) treatment. Moreover, in case of seed and soil treatment with biofungicides, the lowest disease incidence (4.87%) was recorded from T (Decoprima) and the highest disease incidence (49.92%) was observed from T 0 4 (control). Significantly the highest yield /pot (17.83 g) was found in T (Decoprima) treatment. In field experiment, the lowest disease incidence (10%) was recorded from T 4 (Tricost) and the highest disease incidence (48.89%) was observed from T 0 5 (Control). The highest yield /plot (437.67 g) and yield/m 2 (145.89g) found in T (Tricost) treatment. Thus, seed and soil treatment with Trichoderma based bio-fungicides significantly reduced foot and root rot disease of lentil.
INCIDENCE AND SEVERITY OF MAJOR POTATO VIRUSES IN SELECTED NORTHERN REGIONS OF BANGLADESH AND MOLECULAR DETECTION THROUGH RT-PCR
(DEPARTMENT OF PLANT PATHOLOGY, 2020) SULTANA, MST. SHAHANA
In the survey study, incidence and severity of major potato viruses were demonstrated in the selected northern regions of Bangladesh. A lab experiment was also conducted for molecular detection of PLRV. The lab experiment was conducted in Molecular Biology and Plant Virology Laboratory under the Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka1207 during January-February 2020. The survey study was conducted in three selected districts of the northern region viz. Bogura, Jaipurhat and Gaibandha. During the survey study, diseased samples were collected randomly and nonrandomly. In total 270 leaf samples of potato were collected from the selected districts. Among the diseased sample 131 samples were infected with virus and virus like symptoms where PLRV+ve 72 samples, PVY+ve 52 samples and PVX+ve 7 samples. From the disease incidence and severity study on the basis of visual observation, it was revealed that PLRV was the most observed, predominant and devastating potato virus in all the selected districts and PVY also came in concern. Bogura was found to be the most infected region with PLRV (disease incidence 30.67% and severity 25.67%). For molecular detection of PLRV, in total 27 samples were considered from each spot and total RNA was extracted from the samples. Total RNA was then being subjected to cDNA synthesis. PLRV was confirmed through RT-PCR at 346bp fragments. Farmers were interested to grow the hybrid varieties for better production in the selected districts. BADC, cold storage and home storage were used as a source of seed tuber. From the study, it may be concluded that PLRV, PVY and PVX are found in all the selected districts. Among the identified potato viruses PLRV was common and appeared with severe outbreak. For detection of PLRV, RT-PCR was the most reliable, highly specific and robust molecular technique.