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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Open Access
Integrative Approaches for Fusarium Wilt Disease Management in Lentil
(Dr.RPCAU, Pusa, 2023) Chaurasiya, Dilip Kumar; Sahni, Sangita
In summary, the study aimed to identify sources of host resistance against the wilt pathogen in lentil genotypes. Out of 114 genotypes tested, only 4 were found to be resistant, 33 were moderately resistant, 30 were moderately susceptible, and 30 were susceptible to the disease. The study used 12 SSR primers to analyze 10 genotypes and found that 11 of the primers were polymorphic. The SSR113 primer pair was the most polymorphic and showed the highest heterozygosity among all the genotypes tested. The study also examined the genetic similarity among varieties and found that the highest genetic similarity was 84.2% between SL 20-Q and IPL-606, and the least genetic similarity was 13.8% between VL-507 and BL-18. The study also evaluated the antagonistic activity of 30 Pseudomonas isolates against the pathogen Fusarium oxysporum f.sp. lentis and found that PGPR 18 exhibited the highest percent mycelial growth inhibition at 85.19%. The study further characterized the potential Pseudomonas isolates based on their biochemical characters such as P-solubilization, K-solubilization, IAA production, NH3 production, siderophore production, HCN production, amylase activity, catalase, and citrate utilization. Out of the 6 isolates tested, 5 were found to have P-solubilization ability, 3 had K-solubilization ability, 2 were positive for citrate utilization, and 5 were positive for indole production. Two isolates (PGPR-18 and PGPR-16) were found to have the highest cellulase activity. Substituting soil with vermicompost (VC) at 5%, 10%, and 15% levels improved growth parameters of lentil plants such as emergence, height, number of branches, pods, seeds, and fresh and dry weights. The highest growth was observed at 15% VC substitution (T5) followed by 10% and 5% VC substitution. Seed bacterization with PGPR18 alone also improved growth parameters, but the best results were obtained when it was combined with VC substitution. Among all eight treatments, the combination of 15% VC substitution and seed bacterization (T8) resulted in the best growth and seed yield, followed by T7 and T6. The use of Salicylic acid as a pre-inoculation foliar spray greatly reduced wilt incidence in lentil plants, resulting in a 52.71% wilt incidence compared to 72.36% with ZnSO4. The combination of Salicylic acid with seed bacterization with PGPR18 and vermicompost amendments resulted in the least wilt incidence of 3.75%. Treatment T9, a combination of 15% vermicompost amendment and seed bacterization with PGPR18 without non-conventional chemicals, also showed significant results with 21.69% wilt incidence recorded 30 days after. Overall, all treatments showed high suppression of wilt disease when applied 24 hours before pathogen inoculation and Salicylic acid was found to be more effective than ZnSO4.
Open Access
Studies on Leaf blight of Oilseed Brassica incited by Alternaria spp.
(Dr.RPCAU, Pusa, 2022) Kumar, Sanjeet; Choudhary, C. S.
Rapeseed-Mustard globally known as “Oilseed brassica” holds the status of the third most important oilseed crop with the production of about 72 MT from about 35 m ha area. In terms of area and production, India stands third place, and fifth place in terms of productivity. Currently in India, oilseed brassica is dominated by Indian mustard (B. juncea) covering 90% acreage. Alternaria leaf blight caused by A. brassicae (Berk.) Sacc., is the most destructive disease of Indian mustard without any confirmed source of transferable resistance, causing yield loss of 47% and reported from all parts of the world. This disease affects and damage foliage, stem, branches and pods of the brassica crop resulting into severe deterioration of both seed yield and oil content. Considering its seriousness, the present investigations were accomplished to understand the current status of disease severity and related variability in the pathogen in Bihar as well as efficacy of cultural, chemical, botanical, biological and SAR methods to minimize the yield loss. Alternaria blight disease of oilseed brassica prevailed in all parts of Bihar with varying severity from 35.30% at Bhagalpur in zone IIIA to 61.85 percent at Dholi, Muzaffarpur in zone I. The disease symptoms first appear on inter-rib tissues of lower leaves as small round, minute brown to blackish spots usually surrounded with zone of yellow halo that form lesions of varying sizes with inside concentric rings, lesions coalesce to cause blighting and defoliation of leaves. The symptom as elongated lesions with both ends in pointed shape with ash coloured center, appear on stem and branches and as sunken, dark-brown spots and lesions on pods. The symptom became noticeable in the first week of December month at lower leaves of the crop of 45-50 days age, which increased to maximum 54.2% on leaf and 48.2% on pods till crop maturity stage. Weather condition during reproductive phase of crop favoured the rapid progress of disease. On the basis of morphological characters of the pathogen isolated from all the surveyed areas, it was identified as Alternaria brassicae. Among 15 collected isolates of the pathogen from surveyed sites, a large extent of variability had been found. Variability in the conidial length from 100 to 330μm, thickness from 14 to 48 μm and beak length from 48 to 178 μm, number of transverse septa from 8 to 18, number of longitudinal septa from 0 to 8, mycelial growth from 44.82 mm on A & H Agar media to 68.76 mm on Richards Agar, colony colour on PDA from olivaceous black to whitish black, growth pattern adherent circular or fluffy circular, mycelial dry weight of 121.30 mg in AHA to 185.30 mg in RA, spore density of isolates in x 103 number per ml from 2.47 in Czapek's Dox Agar to 7.56 in Mustard leaf decoction were recorded. Among 15 isolates, 4 were found highly virulent, 7 as moderately virulent and other 4 as virulent. Dendrogram of molecular variability using ISSR primers also categorized isolates into four groups with variable polymorphism and dissimilarity. In bioassay studies of eight fungicides Propiconazole 25EC and Trifloxystrobin 25% + Tebuconazole 50% WG were proved to be 100 % inhibitory to A. brassicae in in vitro at all three tested concentration of 250, 500 and 1000 μg/ml; of six botanical extracts used at 5, 10, 15 and 20 % concentrations; Tobacco, Neem and Garlic extract at 20 % proved to be 81.9%, 72.2% and 51.4% inhibitory respectively; of four SAR activators used at concentration of 50,100,150 and 200 μg/ml; Azoxystrobin, INA, BABA and SA at 200 μg/ml proved to be 43.83, 27.78, 22.22, 14.81% inhibitory respectively. In antagonism study, all the four antagonists T. viride, T. harzianum, P. flourescens and B. subtilis inhibited the growth of test pathogen by 79.52, 73.49, 61.44 and 42.17 % respectively in dual culture. Microscopic observation on hyphal interactions between T. viride and A. brassicae showed lysis, protoplasmic disintegration and coiling around the mycelia of A. brassicae at many locations. Under field condition, timely sown crop on 15th October at spacing of 30 X 10 cm2 gave maximum yield of 1865.5 kg ha-1 found at par to 1831.5 kg ha-1 with spacing of 30 x 20 cm2. Successive delay in sowing from 15th October to 15th November resulted into rapid enhanced of the severity of Alternaria blight on leaf (from 19.53 to 55.39%), on pod (from 10.45 to 48.79%) and thereby gradual reduction of test weight of seed (from 5.51g to 4.56 g) and seed yield (from 1810.50 to 996.10 kg/ha) of mustard crop. Widening of spacing from 30 x 10 cm2 to 60 x 20 cm2 resulted into slight reduction of the disease severity on leaf and on pod, slight enhancement of test weight but decreased the seed yield from 1488.50 kg to 1390.90 kg/ha. Successive 10 days delay in sowing from 15th October to 15th November increased the days to attain 50 % flowering from 58 days to 66 days but shortened the days to attain physiological maturity from 148 to 136 days, thereby reducing the reproductive phase from 90 to 70 days which coupled with increased disease severity resulted into drastic reduction of yield by 44.11% (from 1866 to 1043 kg/ha), net return by 46.62 % (from Rs. 87,620 to Rs. 38,010 per ha) and Benefit: Cost ratio from 3.04 to 2.09. In bio control trial T. viridae and T. harzianum, proved at par in reducing the disease intensity by 44.76 and 39.52 %, enhancing the seed yield by 22.99 and 19.7 % and gave the ICBR of 1: 3.04 and 1: 2.61 respectively. Among botanical extracts Garlic gave maximum disease reduction of 36.61%, seed yield of 1484 kg ha-1 with increase of 18.34 % followed by yield of 1456 kg ha-1 with increase of 16.11% in Tobacco extract, but the highest ICBR of 1:5.34 obtained with Tobacco due to its low cost. In fungicidal trial Propiconazole 25EC @ 0.1% proved to be most economical and effective with ICBR of 1: 5.64, disease reduction by 72.49 %, yield of 1700.50 kg ha-1 and yield enhancement by 36.75 % followed by Trifloxystrobin 25% + Tebuconazole 50% WG @0.1% with ICBR of 1: 3.35, disease reduction by 75.73%, yield of 1731.50 kg ha-1 and yield enhancement by 39.24 %. In SAR trial Isonicotinic Acid (INA) caused maximum disease reduction by 53.12%, yield of 1637.5 kg ha-1 with its enhancement by 31.16 % and ICBR of 1:6.58 which was found at par with Salicylic acid (SA) in terms of yield (1603.00 kg ha-1) with its increase by 28.39% and ICBR of 1:5.99.
Open Access
Studies on Variability and Eco-friendly Management of Sugarcane Red Rot Disease Caused by Colletotrichum falcatum Went.
(Dr.RPCAU, Pusa, 2022) SINGH, PRIYA; Minnatullah, Md.
Sugarcane is an economically important agro-industrial crop cultivated in tropical as well as subtropical parts of the country. It is chief source of white sugar, jaggery, khandsari and other bio products. The low yield and productivity of sugarcane can be attributed to infection by numerous plant diseases. Among them, red rot disease caused by Colletotrichum falcatum Went. is the most common and dreaded disease of sugarcane. The sugarcane plant exhibiting typical red rot symptoms were collected from the various reserved areas of sugar factories in Bihar. A total of twenty seven isolates of pathogen was obtained and they were studied for their cultural and morphological characteristics. The various colour of colony such as white, whitish grey, greyish white, ashy grey, light brown and pinkish white and colony margin either smooth or irregular were observed. The various pigmentation on the reverse side of the plate viz. creamish, light yellow, dark yellow, light pink and black were observed. The mycelia of the isolates were either aerial or subaerial, sparse, scanty or abundant with flat, slightly raised to fluffy texture. The average length of conidia varied from 19.87 to 31.47 μm and width varied from 3.74 to 4.72 μm. The pathogenic behaviour of the isolates revealed that fourteen isolates were similar to Pathotype-1 (CF 08), six isolates as Pathotype-2 (CF 07) and seven isolates behaved as Pathotype-3 (CF 01). Amongst 48 genotypes/varieties evaluated against sugarcane red rot disease, 10 genotypes/varieties were graded as resistant, 26 as moderately resistant, 6 as moderately susceptible and 6 as susceptible against the isolate CF 07. However, 8 genotypes/varieties showed resistant, 24 as moderately resistant, 8 as moderately susceptible and 8 as susceptible reaction against CF 08 isolate. In vitro efficacy of fungicide indicated that Carbendazim was most effective in inhibiting the mycelial growth of the test fungus followed by Propiconazole while, Azoxystrobin was least effective against all the three pathotypes. In vitro evaluation of botanicals revealed that Neem leaf extracts proved most efficacious followed by Tulsi while, Bael was least effective against all the three pathotypes of red rot pathogen. Amongst all the intercrops evaluated with sugarcane under field condition for two consecutive cropping seasons i.e. 2019-20 and 2020-21, sugarcane intercropped with garlic showed outstanding results in both the cropping seasons followed by coriander while lentil was most inferior among all the treatments in reducing red rot disease, enhancing germination and yield attributes of sugarcane. Among all the fungicides, botanicals and micronutrients evaluated under the field condition for two cropping seasons i.e. 2020-21 and 2021-22, Sett treatment + drenching + spraying with Carbendazim + Furrow application of Borax + Zinc sulphate proved most effective in reducing red rot disease incidence and enhancing all other cane attributes. Although botanicals were inferior in comparison to three used fungicidal treatments however, botanicals were found comparatively superior to fungicides in terms of enhancing micronutrients availability and soil quality. The botanicals positively favoured the availability of soil organic carbon, availability of macronutrients (N, P and K) and micronutrients (Fe, Mn and Cu) in the soil. Based on the above findings, it may be concluded that a holistic combination of various disease management approaches i.e. selection of resistant varieties for planting, intercropping of sugarcane with suitable crops, use of fungicides, botanicals as well as micronutrients would lead to long term sustainability and higher profitability
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, Phool
Maydis 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.
Open Access
Studies on variability and holistic management of Sarocladium oryzae
(Dr.RPCAU, Pusa, 2021) J N, NITHIN KUMAR; Rai, Bimla
Rice 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.
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).
Open Access
VARIABILITY AND MANAGEMENT OF PIGEONPEA WILT (Fusarium udum Butler)
(Dr.RPCAU, Pusa, 2021) REDDY, BEERELLI DEEPAK; Kumar, Birendra
Pigeonpea (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).
Open Access
Epidemiology and integrated management of Banded leaf & sheath blight of maize caused by Rhizoctonia solani f. sp. Sasakii (Kuhn.) Exner
(DRPCAU, Pusa, 1996) Kumar, Vinay; Jha, M.M.
Open Access
Studies on Wilt complexes in Banana and its management
(DRPCAU, Pusa, 1996) Roy, Shambhu; Ojha, K.L.

Dr. Rajendra Prasad Central Agricultural University, Pusa

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