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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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20222
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Subject: Plant Pathology × End date: 2022 × Start date: 2022 × Thesis Type: Ph.D ×
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    ThesisItemOpen 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.
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    ThesisItemOpen 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