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Dr. Rajendra Prasad Central Agricultural University, Pusa
In the imperial Gazetteer of India 1878, Pusa was recorded as a government estate of about 1350 acres in Darbhanba. It was acquired by East India Company for running a stud farm to supply better breed of horses mainly for the army. Frequent incidence of glanders disease (swelling of glands), mostly affecting the valuable imported bloodstock made the civil veterinary department to shift the entire stock out of Pusa. A British tobacco concern Beg Sutherland & co. got the estate on lease but it also left in 1897 abandoning the government estate of Pusa.
Lord Mayo, The Viceroy and Governor General, had been repeatedly trying to get through his proposal for setting up a directorate general of Agriculture that would take care of the soil and its productivity, formulate newer techniques of cultivation, improve the quality of seeds and livestock and also arrange for imparting agricultural education. The government of India had invited a British expert. Dr. J. A. Voelcker who had submitted as report on the development of Indian agriculture. As a follow-up action, three experts in different fields were appointed for the first time during 1885 to 1895 namely, agricultural chemist (Dr. J. W. Leafer), cryptogamic botanist (Dr. R. A. Butler) and entomologist (Dr. H. Maxwell Lefroy) with headquarters at Dehradun (U.P.) in the forest Research Institute complex.
Surprisingly, until now Pusa, which was destined to become the centre of agricultural revolution in the country, was lying as before an abandoned government estate. In 1898. Lord Curzon took over as the viceroy. A widely traveled person and an administrator, he salvaged out the earlier proposal and got London’s approval for the appointment of the inspector General of Agriculture to which the first incumbent Mr. J. Mollison (Dy. Director of Agriculture, Bombay) joined in 1901 with headquarters at Nagpur
The then government of Bengal had mooted in 1902 a proposal to the centre for setting up a model cattle farm for improving the dilapidated condition of the livestock at Pusa estate where plenty of land, water and feed would be available, and with Mr. Mollison’s support this was accepted in principle. Around Pusa, there were many British planters and also an indigo research centre Dalsing Sarai (near Pusa). Mr. Mollison’s visits to this mini British kingdom and his strong recommendations. In favour of Pusa as the most ideal place for the Bengal government project obviously caught the attention for the viceroy.
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ThesisItem Open Access Studies on Variability and Management strategies of Maydis leaf blight disease of maize caused by Helminthosporium maydis Nisik.(Dr.RPCAU, Pusa, 2021) KUMAR,CHANDAN; Chand, PhoolMaydis leaf blight (MLB) caused by Helminthosporium maydis (Nisikado and Miyake) Shoemaker is one of the major disease of maize. The disease is present in almost all maize growing areas and is a major limiting factor in increasing yield. Therefore, in vitro and field studies were conducted to elucidate different aspects of pathogen biology, disease progress and effective management of disease. Pathogen produced grey to dark grey conidial colonies and the mycelium was fluffy, cottony, grey to olivaceous in colour. Conidia were 5-11 septate olivaceous brown, spindle-shaped with tapering to round ends and bipolar germination. Conidia originated on straight to flexous, pale to dark brown conidiophores, appearing as single or in small groups. At, the base of conidia a small, protruding, slightly papillate hilum was observed Potato Dextrose agar media and Richard‘s agar media, 2 C temperature, pH 8, were found best for growth and sporulation of H. maydis. In vitro evaluation studies revealed that among the fungicides Propiconazole, Carboxim, Thiram and Mancozeb were found most effective in inhibiting growth of pathogen. While in non-chemical methods of management, Turmeric, Garlic and Neem extract and RT-6 isolate of Trichoderma harzianum, were found most effective. Under field conditions, observations on loss estimation revealed that lower disease index resulted in increased grain yield in T5 (Carbendazim+Mancozeb ST + Propiconazole spray) treated plants. The study on effect of spacing and nitrogen doses on the disease also conducted. Under glass house and field conditions, sixty five days old plants were found most vulnerable to infection. In biochemical studies for elucidation of defence induction, biochemical markers reached maximum on third day after pathogen inoculation and INA treatments were found most effective.ThesisItem Open Access Studies on variability and holistic management of Sarocladium oryzae(Dr.RPCAU, Pusa, 2021) J N, NITHIN KUMAR; Rai, BimlaRice is worlds' second most important cereal crop, with approximately twothirds of the world's population relying on it for survival. Rice production is influenced by various biotic and abiotic factors. Among the many biotic variables impacting rice production and productivity, fungus, bacteria, virus, and nematodes are the most significant constraints responsible for low productivity. Sheath rot has emerged as a serious disease that causes qualitative and quantitative yield losses ranging from 3-85%. During Kharif 2018 and 2019 survey conducted in seven districts of Bihar (Zone I) indicated the maximum disease incidence in Madhubani and the lowest in Sitamarhi districts. All the villages in seven districts showed significant variance in disease incidence. Fourteen Sarocladium oryzae isolates collected, two from each districts of the Bihar (Zone I) observed significant variability in Mycelium color, colony diameter, conidiophores and conidia length and conidia per sq. cm on PDA media. All the isolates had fluffy irregular growth on PDA, eight isolates had mycelia colour were whitish with pale orange, two isolates whitish with deep orange and four isolates whitish with orange ochre. Isolate Sob-8 (0.85cm) and Sob-11 (0.95cm) had the least growth while isolate Sob-7 (3.20cm) had maximum radial growth, maximum dry weight was observed in Sob-7 (0.95g) while the mycelial dry weight was found to be the smallest in Sob-8 (0.32g), maximum length of Conidiophore was recorded in isolate Sob-4 (57.9μm) while the least length of Conidiophore was recorded in isolate Sob-8 (46.7μm). Longest length of conidia was observed in isolate Sob-10 (5.95μm) while the least conidial length was observed in Sob-5 (4.65μm). Sob-7 isolate found to be most virulent in the assessment of pathogenic variability study. Azoxystrobin 11 % + Tebuconazole 18.3 % and carbendazim 25 % + Mancozeb 50% showed 100 % growth inhibition of S. oryzae when tested in vitro using the poisoned food technique at three different dosages. Clove oil was shown to be efficient with 66.60 % suppression at 100ppm and 100% inhibition at remaining concentrations, whereas botanical extracts of Datura and Calotropis inhibited S. oryzae isolate growth by more than 50% at 40% concentration. At all three concentrations, the homoeopathic drug Sulpher showed 100% inhibition. When four isolates of Trichoderma spp. and a isolates of Pseudomonas fluorescens were assessed for their in vitro antagonistic effect against Sob-7 isolate, Pseudomonas fluorescens isolate led to a considerable influence on S. oryzae growth. In field conditions carbendazim 25 % + Mancozeb 50 % WS found to be the most effective among fungicides controlling disease (57.02%), lemongrass oil effective with 31.12% disease control followed by Niragundi oil, clove oil. Both the homeopathic drugs were not effective against the disease in field conditions. Among 148 germplasms screened against sheath rot disease of rice three germplasms viz., IR- 64, IET 25618 and IET 26178 were found to be highly resistant to sheath rot disease.ThesisItem Open Access Ecofriendly Approach for the Management of Black spots of Aloe vera caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc.(Dr.RPCAU, Pusa, 2021) KUMARI, MINA; Jha, P.K.Aloe vera is an important medicinal plant and widely cultivated in tropical and sub-tropical region. Like other crops it is also attacked by a number of pests and diseases. Among these, black leaf spot is most serious problem in Aloe vera throughout the country resulting in reduction in yield and market value. Its causal organism was isolated and identified as Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. During survey in five districts of North Bihar, highest PDI (32.50%) was recorded in Samastipur while the lowest in Madhepura (22.00%). Five isolates of pathogen obtained from five districts varied in their cultural and morphological features. Pathogenicity test was confirmed by employing Koch‟s postulates. In inoculum density test, the least incubation period (12-14 days) was required at 1.9 x 107 spores/ml followed by 15 days at 2.5 x 106 spores/ml. With increase in concentration of inoculum density, the incubation period was decreased. In course of study, 15 fungal species was recorded with phylloplane and rhizosphere of Aloe vera. The isolates of Rhizopus stolonifer and Penicillium chrysogenum showed their presence in rhizosphere only whereas Curvularia lunata and C. gloeosporioides were recorded only from phylloplane and 11 mycoflora were common in both phylloplane and rhizosphere. When these mycoflora were evaluated for their effect on plant growth promotion in pot experiment, most of them showed growth promoting effect and increased biomass production, whereas C. gloeosporioides, Fusarium solani, Alternaria, Curvularia and Cladosporium sp. showed pathogenic effect and hampered plant growth. The beneficial mycoflora which promoted plant growth in pot condition, were also found effective in suppressing the pathogen in dual culture test. Among them, T. harzianum showed maximum mycelium growth inhibition (76.19%) followed by T. viride (73.59%). In culture filtrate assay, culture filtrate of A. niger was most effective and exhibited 29.40% spore germination, thereby resulted in 63.25% inhibition of spore germination at 5% concentration. The next most effective culture filtrate was that of T. harzianum with 61.8% inhibition of spore germination followed by T. viride (59.49%) and T. asperellum (57.99%). However, culture filtrate of T. harzianum was most effective and inhibited colony growth by 86.90% followed by T. viride (85.76%) at 15% concentration. Out of nine botanicals, the Neem leaf extract was found superior in checking the pathogen growth by 74.82% followed by Tulsi (59.78%) at 10% concentration. Among two molecules tested, carbendazim was most effective and inhibited the pathogen growth by 93.52% followed by azoxystrobin (93.07%) at 250 ppm. In compatibility test, both bioagents (T. harzianum and T. viride) were highly compatible with leaf water extracts of Neem and Tulsi at all the four concentrations. When tested for compatibility with two effective molecules, it was highly compatible with only one molecule i.e., azoxystrobin, and not compatible with other effective molecule carbendazim. During field trial on integrated disease management, the most effective treatment was foliar spray with azoxystrobin @ 250 ppm accompanied with soil drenching of T. harzianum @ 5% which caused 82.63% reduction in PDI. Likewise the foliar spray of azoxystrobin @ 250 ppm accompanied with soil drenching of T. harzianum @ 5% and further foliar spray with Neem extract @ 10% also showed promising disease control (81.40% reduction). The treatment combination having Trichoderma harzianum as a component showed prominent growth promoting effect on plants as evident from the observation in the present study that foliar spray with azoxystrobin @ 250 ppm accompanied with soil drenching of T. harzianum @ 5% and further foliar spray with Neem extract @ 10% recorded maximum plant height (33.12 cm) with maximum number of leaves (10/plant). Likewise soil drenching of T. harzianum @ 5% accompanied by foliar spray with Neem @ 10% also recorded the plant height of 32.02 cm and number of leaves (9.61/plant).ThesisItem Open Access VARIABILITY AND MANAGEMENT OF PIGEONPEA WILT (Fusarium udum Butler)(Dr.RPCAU, Pusa, 2021) REDDY, BEERELLI DEEPAK; Kumar, BirendraPigeonpea (Cajanus cajan (L.) Millsp.) is one of the most important legume pulse crop in the world. Wilt caused by Fusarium udum is major disease in pigeonpea and causing severe losses. The present experiment was carried out to know the variability among Fusarium pathogen isolated from pigeonpea and collected from various states of India. The experiments were carried out on cultural, morphological, molecular and pathogenic variability of Fusarium isolates. In host plant resistance experiment an attempt were made to identify stable and resistant genotypes against pigeonpea wilt by using advanced statistical models. In integrated disease experiment botanicals, fungicides, endophytes, rhizosphere bacteria and Trichoderma were used for the management of disease. A total of 50 Fusarium samples collected from eight states India. i.e., Bihar (20), Uttar Pradesh (2), Jharkhand (1), New Delhi (1), Maharashtra (2), Andhra Pradesh (8), Karnataka (6) and Telangana (10) during Kharif 2019-2020 and Kharif-2020-2021. For quick detection of virulent isolates pathogenicity was proved through water culture technique and all the isolates exhibited wilt symptoms and in glass house conditions the wilt incidence ranged from 70.81% ( Fsp 45 ) to 100% Fsp 11 Based on growth rate isolates were cetegorized into three groups i.e., fast growing (81 90 mm) (23 isolates), moderate growing (71 80 mm) (20 isola tes) and slow growing (<70 mm) (s even isolates). Based on mycelial growth pattern isolate s were grouped into fluffy (12), moderately fluffy (10), appressed (20) and moderately appressed (eight). Among 50 isolates, 22 isolates were white, 13 isolates off white, eight isolates were mauve and seven isolates were buff colour. Among 50 isolates, eight (buff), nine (yellowish white), seven (plum), 11 (white), four (yellow), seven (mauve), three (red) and one (pink) colour pigmentation. Microconidia were observed with (0 to 1) septa in all the isolates. Among the isolates the size of microconidia varied between 5.37×2.44 (Fsp 24) to 13.58×3.33 (Fsp 32) and the size of macroconidia varied from 16.62×3.35 (Fsp 35) to 39.05×4.61 (Fsp 33). Genomic DNA extracted from 24 Fusarium isolates, were amplified with five SSR primers. All the SSR primers were amplified with polymorphic percentage ranging from 66.6 (MB 18) to 100.00 (Mb-2, Mb-11 and Mb-13), yielding a total of 27 bands, which varied from 2 (Mb 2) to 12 (Mb 11) in Fusarium isolates. The no of monomorphic bands ranged from zero (MB 2, MB 11, and MB 13) to 1(MB 14, MB 18). The mean number of bands and polymorphic bands per primer were 5.4 and 5 respectively. A genetic dissimilarity dendrogram were created using DARwin 6 software to compute comparative amplification data of five SSR primers among 24 Fusarium isolates and it produced 6 clusters. Phylogenetic analysis of Fusarium isolates was performed using 23 sequences of 18s rDNA, six references and one out group. The phylogenetic tree showed the formation of four major clusters, the first cluster forms the two sub clusters having 15 Fusarium udum isolates, the second major cluster consists of five Fusarium solani isolates, the third major cluster of three Fusarium equiseti isolates. A total of 30 Fusarium isolates were screened against eight pigeonpea standard host differentials i.e., ICP2376, BAHAR, ICP9174, ICP8858, ICP885 9, ICP 8863, ICP8862 and BDN 2. Among 30 isolates, 14 isolates were categorized in variant II, six isolates were categorized in variant III, one isolate as variant IV, six isolates as variant VII and three isolates as Variant VIII. In cultrate filtrates germination percentage of pigeonpea seeds were considerably reduced in all the Fusarium isolates when compared to control. Across the isolates root length varied from 9.9 cm (Fsp 46) to 15.6 (Fsp 33). AMMI ANOVA of Fusarium wilt revealed that among total sum of squares (SS), 72.33 % of the SS was observed for genotype effect, 0.52% of SS provides environment effect and 15.78% of SS was observed for interaction effect (G×E). The GEI was further divided into Interaction Principal Component Axis (IPCA) and residuals, in which IPCA1 has contributed 68.31% of SS followed by IPCA2 which contributed 31.68% of SS, and IPCA1 and IPCA2 cumulatively contributed to 99.99% of the total SS. The Fusarium wilt biplot shows that Kharif-2019 was the most discriminating environment and Kharif-2018 was the least discriminating environment. Kharif-2018 were ideal test environments for Fusarium wilt testing because in biplot they were close to the “average environment” and “ideal test environment”, and Kharif-2019 and Kharif-2020 were least representative because they were away from AEA. Fusarium wilt biplot revealed that two mega environments existed in the study. First includes two test environments (Kharif-2018 and Kharif-2019), remaining test environment (Kharif-2019) befitted second mega environment. Among seven botanicals garlic and turmeric exhibited highest antagonistic activity against Fusarium udum. The fungicides Azoxystrobin+Tebuconazole, Carbendazim, Tebuconazole+Trifloxystrobin, Hexaconazole, and Tebuconazole exhibited 100% inhibition at all the concentrations against Fusarium udum. The total of 50 endophytic bacteria were isolated, among them 30 endophytes were further selected for antagonistic studies. The colony morphology of the 30 endophytic bacterial isolates were studied at 72 hours of incubation. Among all the endophytic bacteria, the highest inhibition per cent was observed in Eb-21(72.22), followed by Eb-13 (61.11), Eb-8(44.44) and Eb-11(38.88). A total of 40 bacterial isolates were obtained from rhizosphere soil samples of pigeonp pea plants T.C.A, Dholi. Based on the morphological characteristics among 40, a total 20 bacteria were selected for further studies. At 72 hours of incubation colony characteristics i.e., shape, pigmentation, margins, appearance and size of the bacterial isolates were recorded. Among all the rhizosphere bacteria highest inhibition per cent was observed in Rb-18(71.11), followed by Rb-14(68.44), Rb-19(63.3), Rb-4(58.8). Among 30endophytic bacteria, based on the antagonistic activity against Fusarium udum, four potential endophytes were selected i.e., Eb-21 (72.2272.22), Eb-13 (61.11), Eb-8 (44.4444.44), Eb-11(38.8838.88), similarly from 20 rhizosphere bacteria, five bacteria i.e., Rb-18 (71.1), Rb-14 (68.4468.44), Rb 19 (63.33), Rb 4 (58.8) and Rb 11 42.11 were selected for biochemical identification i.e., Gram staining, KOH, amylase, catalase, indole, citrate, MR (Methyl Red), VP (Voges-Proskauer), oxidase to identify the potential isolates based on biochemical characters. Based on 16s rDNA dtata, the potential bacterial isolates i.e., Eb-21 and Rb 18 were identified as Pseudomonas aeruginosa as Bacillus subtilius respectively . The two sequences were submitted in the NCBI Gen bank and accession numbers (MZ3488967.1 and MZ348896.1) were obtained. A total four Trichoderma cultures were isolated from Dholi pigeonpea fields and for identification ITS sequencing were conducted. The results showed similarity of Trichoderma harzianum at 100 per cent similarity, Trichoderma asperellum at 99.33 similarity, Trichoderma asperelloide s at 99.31 and Trichoderma sp. at 98.97%. The Trichoderma cultures were submitted to NCBI Gen bank and the accession number Trichoderma harzianium (MZ348898.1), Trichoderma asperellum (MZ411690.1), Trichoderma asperelloides (MZ411689.1), Trich oderma sp. MZ411691.1) were obtained. The four Trichoderma cultures were evaluated against Fusarium udum isolates under in vitro conditions. The inhibition per cent of Trichoderma harzianum against Fusarium udum isolates 1, 2, 3, 4 were 30, 30, 33.3 and 50 per cent respectively, inhibition per cent of Trichoderma asperellum against Fusarium udum isolates (1, 2, 3, 4) were 30, 50, 26.6 and 40 per cent respectively, inhibition per cent of Trichoderma asperelloides against Fusarium udum isolates (1, 2, 3 a nd 4 ) were 40, 30, 33.3 and 50 per cent respectively, finally inhibition per cent of Trichoderma sp . against Fusarium udum isolates (1, 2, 3 and 4) were 80, 73.3, 86 and 56.6 respectively. Fungicides, botanicals and bio agents effective under in vitro conditions were used for the management of pigeonpea wilt under glass house condition. Among all the treatments, T12 (Seed treatment with carbendazim + soil application of Pseudomonas aeruginosa + Soil application of Trichoderma sp.+ soil application of Garlic extract) recorded the lowest disease incidence (2.77).ThesisItem Open Access S election of native Trichoderma strain with Biocontrol potential from sugarcane rhizosystem(Dr.RPCAU, Pusa, 2021) Rajput, Virendra Singh; Dwivedi, MeenakshiIn the currently studies, Trichoderma samples were isolated from rhizosystem of sugarcane crop. The isolates were vigorously tested for their Biocontrol potential. On the basis of their antagonistic potential against C. falcatum pathotypes Cf 07 and Cf 08, the promising isolates were selected. A total of 27 isolates each were obtained from samples from SRI, Pusa and Harpur Jhilli, Pusa. Based on visual cultural differences, 19 isolates were screened from SRI sample and 16 isolates were from Harpur Jhilli sample. Out of the isolates, T SR 11, T HJ 7, T HJ 14 and T. asperellum stronglyinhibited the growth of the pathogen in vitro. The isolates were then dual cultured with the pathotypes in the presence of fungicides (carbendazim 50 WP and azoxystrobin 23 SC), in order to create a micro-environment so that all the three components can interact with each other at the same time. It was found that carbendazim completely inhibited Trichoderma isolates at all the doses (RD, ½ RD, ¼ RD). Hence it cannot be used with Trichoderma under IDM programme. Whereas, azoxystrobin 23 SC was found to be compatible with Trichoderma isolates. Moreover, it was found to aggravate the growth of Trichoderma isolates and suppress the growth of the pathogen. Inhibition of pathogen by ½ RD and ¼ RD in integrated approach was comparable with inhibition at RD of the fungicide. Hence, it was concluded that azoxystrobin 23 SC could be used in reduced doses (1/2 RD and ¼ RD) with BiocontrolTrichoderma isolates and still would be able to manage the pathogen effectively. Hence, it gives a hope that effective IDM strategy against rd rot could be chalked out including azoxystrobin and compatible BiocontrolTrichoderma isolates.ThesisItem Open Access Evaluation of button mushroom Agaricus bisporus (Lange)Imbach germplasm for yield potential under Bihar condition(DRPCAU, PUSA, 2021) P, RAMESH; Nandni, SudhaThe present work entitled “Evaluation of button mushroom Agaricus bisporus (Lange)Imbach germplasm for yield potential under Bihar condition” was carried out at Advance Centre of Mushroom Research, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur,Bihar as well as Mushroom Unit, T.C.A., Dholi. The button mushroom germplasms viz., IVTB-18-01, IVTB-18-03, IVTB-18-05, IVTB-18-09 and the local strain AB-18-03 were evaluated for different growth characteristics including growth on different media viz., Potato Dextrose Agar (PDA), Malt Extract Agar (MEA), Yeast Extract Potato Dextrose Agar (YEPDA), and Compost Extract Agar (CEA) at 7th DAI and 14th DAI under invitro conditions. The Compost Extract Agar media showed the best mycelial growth i.e.39.7 and 86.9 mm after 7th DAI and 14th DAI respectively. The maximum colony diameter was observed in the germplasm IVTB-18-09 after 7th DAI (44.5 mm) and 14th DAI (90.0 mm). The minimum number of days for spawn run in wheat grains were recordedwithIVTB-18-03 (15 days) while spawn runin compost was recorded to be minimum withIVTB-18-09 (15 days). The germplasm IVTB-18-09 was observed with minimum number of days (10 days) taken for casing to pinhead formation, minimum number of days (18 days) for casing to first flush harvest, maximum pileus diameter (44.5 mm) and the highest stipe diameter(52.1 mm), while the germplasm IVTB-18-05 had a maximum stipe length of (20.2 mm). The highest number of fruiting bodies (167 nos.), yield (2298 g)and biological efficiency (32.8%) were obtained from the germplasm IVTB-18-09. The minimum green mould, bacterial blotch, and inky cap incidence occurred in the local strain AB-18-03. Finally concluded that the germplasm IVTB-18-09 wasfound to be suitable for cultivation under the Bihar condition.ThesisItem Open Access Eco-friendly Management of Xanthomonas campestris pv. campestris causing black rot of cauliflower(DRPCAU, PUSA, 2021) PATIDAR, RAHUL; Ranjan, Rajesh KumarBlack rot disease is a serious problem in the development of cauliflower, which is one of India's most popular winter vegetables. The pathogen for black rot disease was identified as Xanthomonas campestris pv. campestris through morphological and biochemical characteristics. Colony characters development on NSA medium regards to morphological characters. Biochemical test such as gram staining, indole production, nitrate reduction, KOH string test, catalase test and utilization of different carbohydrates for acid production regard as biochemical characters. In vitro evaluation of 30 rhizobacteria against XCC in which 3 isolates found effective and developed inhibition zone of more than 10 mm. RAC 3 isolates developed maximum inhibition zone of 27.03 mm. Aqueous extract of Neem, Garlic, Bael, Datura and Tulsi were effective at 1:1 (w/v). Garlic extract shows maximum inhibition zone of 13 mm and 15.23 mm at 10% and 15% conc respectively, followed by Neem (11.60 mm and 14.40 mm) and Datura (11.20 mm and 13.83 mm). Beal extract shows inhibition zone of 11.83 mm only at 15% conc and Tulsi failed to produced inhibition zone at all three conc. Evaluation of antibacterial chemical indicates that 0.01% conc. of streptomycin sulphate + tetracycline gave maximum inhibition zone of 22.43 mm followed by streptomycin alone (20.44 mm) and chloramphenicol (18 mm) but at higher conc., chloramphenicol @ 0.02 % and 0.03% developed maximum inhibition zone of 25.89 mm and 27.33 mm respectively, followed by streptomycin sulphate + tetracycline (23.89 mm and 26.32 mm) and streptomycin alone (21.33 mm and 23.87mm).ThesisItem Open Access STATUS OF FUNGAL DISEASES OF IMPORTANT MEDICINAL PLANTS IN SAMASTIPUR, BIHAR(DRPCAU, PUSA, 2021) SINGH, NIDHI; Rai, DineshIndia is a treasure house of medicinal plants and is endowed with precious genetic diversity. They are not an exception and are also attacked by several pathogens, mainly the fungal pathogens that degrade the quality of medicinal active principle which may lead to health hazards instead of curing the disease. A survey was carried out on fungal diseases of economically important five medicinal plants viz. Ashwagandha (Withania somnifera), Sarpagandha (Rauvolfia serpentina), Tulsi (Ocimum sanctum), Mint (Mentha arvensis) and Mandukparni (Centella asiatica) in MAP germplasm blocks at Dr. RPCAU, Pusa and its neighbouring areas at different time intervals. During the survey, eleven fungal diseases namely leaf spot/ blight (Alternaria alternata), wilt (Fusarium solani) and downy mildew (Peronospora sp.) of Ashwagandha, leaf spot (Colletotrichum truncatum) and leaf blight (Alternaria sp.) of Sarpagandha, leaf spot (Colletotrichum gloeosporioides) and leaf blight (Alternaria sp.) of Tulsi, leaf spot (Curvularia lunata) and leaf blight (Alternaria alternata) of Mint and leaf spots (Cochliobolus sp. and Alternaria sp.) of Mandukparni were recorded. There was an increase in disease incidence during November to January. The overall variation recorded in disease incidence of the medicinal plants varied from trace (wilt and downy mildew of Ashwagandha) to 60 per cent (leaf spot of Mandukparni and Sarpagandha). The PDI also varied from trace to 61.11 per cent among the plants. All the isolated pathogens varied significantly in most of their cultural and morphological characteristics. In vitro evaluation of native Trichoderma asperellum showed effective inhibition against the pathogens. Maximum inhibition percent was recorded against Fusarium solani i.e. 56.36 per cent followed by Cochliobolus sp. i.e. 55.38 per cent. Among the tested botanicals and essential oils, Garlic bulb extract was found most effective against most of the pathogens at both 5 and 10 per cent concentrations in showing complete inhibition (100%) followed by Neem leaf extract which showed maximum inhibition of pathogens (Alternaria spp., Fusarium solani, Colletotrichum truncatum, Curvularia lunata, Cochliobolus sp.) at 5 per cent concentration and Bael extract (Alternaria alternata, Cochliobolus sp., Colletotrichum gloeosporioides, Alternaria spp., Colletotrichum truncatum) at 10 per cent concentration. This work may encourage other researchers to study these diseases further and their integrated management using biocontrol agents and plant extracts by properly testing their efficacy in the agrifields.ThesisItem Open Access BIO-RATIONAL MANAGEMENT OF ALTERNARIA LEAF SPOT OF CAULIFLOWER(DRPCAU, PUSA, 2021) SUNITHA, MUMMINENI; Jha, Pk.Cauliflower, which is widely grown throughout the world, is one of the most popular vegetable in Brassicaceae family after cabbage in term of area and production across the globe. Alternaria leaf spot or Alternaria leaf blight, which is the most destructive disease of cauliflower crop at vegetable curd stage and seed setting stage, has been attributed to cause 30-50% losses and in most severe case, the losses in yield may reach up to 98% in seed crop. In the present investigation, the pathogen Alternaria brassicae was found to produce typical symptoms of the disease as small, irregular brown spots with concentric rings, also surrounded by yellow chlorotic halo. Later on lesions were found to coalesce forming irregular, brown to dark brown patches with concentric rings. It was also found to affect petiole, stem and curd at later stages. Severely affected seedlings showed dark brown spots with damping off symptoms. In current investigation, four biocontrol agents i.e. the native isolates of Trichoderma viride and Trichoderma asperellum as well as commercial formulations of Trichoderma viride and Trichoderma harzianum were evaluated for their antagonistic effect on A. brassicae. Among bio-agents, the native isolates of T. viride and T. asperellum were found very effective against Alternaria brassicae with 68.61% and 65.19% growth inhibition, respectively. Aqueous and ethanol extracts of six botanicals (Neem, Datura, Tulsi, Bael, Brahmi, Mandookparni) were tested against A. brassicae. The aqueous extracts of Neem at 10% concentration showed maximum inhibition (54.07%) of target pathogen followed by Datura, Bael. The ethanol extracts of all the test botanicals were able to suppress the growth of the pathogen at all concentrations. At 10% of concentration, Datura and Bael exhibited 100% growth inhibition, at 20% of concentration Tulsi, Bael and Datura were found to exhibit 100% growth inhibition, at 30% and 40% of concentration Tulsi, Neem, Bael and Datura exhibited 100% growth inhibition; while at 50% of concentration, Tulsi, Neem, Bael, Datura and Brahmi exhibited 100% growth inhibition. Nine chemicals were evaluated against A. brassicae by poison food technique at four concentrations of 100ppm, 250ppm, 500ppm and 1000ppm. At 100 ppm concentration Propiconazole showed maximum inhibition (76.66%) followed by Mancozeb. At 250ppm, 500ppm and 1000ppm, Propiconazole showed maximum growth inhibition (100%) of the pathogen. Different level of inoculum of Alternaria brassicae were evaluated to identify the quantity of inoculum in order to develop sick pot for successful disease development. The application of 5.0 gram of inoculum showed quite poor disease development. By increasing the quantity of inoculum, the disease severity (PDI) was found to increase. The inoculum level of 40g induced maximum disease severity (50.81% PDI), at early stages, some plants showed damping off symptoms and some were stunted. Initially symptoms were expressed as small, irregular brown spots, later on spots were merged to form irregular, dark brown patches with concentric rings. During investigation on integrated management under sick pot condition, the combination of T. viride (applied as soil treatment @ 10g/pot) along with spray of Neem (10%) after appearance initial symptom and spray of Azoxystrobin (0.1 %) after 7-day of Neem spray was found most effective in controlling the disease.
