Browsing by Author "Raju Kumar"

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Multi-location evaluation of mungbean (Vigna radiata L.) in Indian climates: Ecophenological dynamics, yield relation, and characterization of locations
(Frontiers Media S.A., 2022) Ashok K. Parihar; Sanjeev Gupta; Kali K. Hazra; Amrit Lamichaney; Debjyoti Sen Gupta; Deepak Singh; Raju Kumar; Anil K. Singh; Rakesh Vaishnavi; M. Samuel Jaberson; Sankar P. Das; Jai Dev; Rajesh K. Yadav; B.S. Jamwal; B.R. Choudhary; O.P. Khedar; Vijay Prakash; Harsh K. Dikshit; R.K. Panwar; Manoj Katiyar; Pankaj Kumar; C.S. Mahto; H.K. Borah; M.N. Singh; Arpita Das; A.N. Patil; H.C. Nanda; Vinod Kumar; Sumer D. Rajput; D.A. Chauhan; M.H. Patel; Raja R. Kanwar; Jitendra Kumar; S.P. Mishra; Hitesh Kumar; Indu Swarup; Suma Mogali; D. Kumaresan; Narayana Manivannan; M. Byre Gowda; Muthaiyan Pandiyan; Polneni J. Rao; D. Shivani; A.M. Prusti; P. Mahadevu; K. Iyanar; Sujata Das
Crop yield varies considerably within agroecology depending on the genetic potential of crop cultivars and various edaphic and climatic variables. Understanding site-specific changes in crop yield and genotype × environment interaction are crucial and needs exceptional consideration in strategic breeding programs. Further, genotypic response to diverse agro-ecologies offers identification of strategic locations for evaluating traits of interest to strengthen and accelerate the national variety release program. In this study, multi-location field trial data have been used to investigate the impact of environmental conditions on crop phenological dynamics and their influence on the yield of mungbean in different agroecological regions of the Indian subcontinent. The present attempt is also intended to identify the strategic location(s) favoring higher yield and distinctiveness within mungbean genotypes. In the field trial, a total of 34 different mungbean genotypes were grown in 39 locations covering the north hill zone (n = 4), northeastern plain zone (n = 6), northwestern plain zone (n = 7), central zone (n = 11) and south zone (n = 11). The results revealed that the effect of the environment was prominent on both the phenological dynamics and productivity of the mungbean. Noticeable variations (expressed as coefficient of variation) were observed for the parameters of days to 50% flowering (13%), days to maturity (12%), reproductive period (21%), grain yield (33%), and 1000-grain weight (14%) across the environments. The genotype, environment, and genotype × environment accounted for 3.0, 54.2, and 29.7% of the total variation in mungbean yield, respectively (p < 0.001), suggesting an oversized significance of site-specific responses of the genotypes. Results demonstrated that a lower ambient temperature extended both flowering time and the crop period. Linear mixed model results revealed that the changes in phenological events (days to 50 % flowering, days to maturity, and reproductive period) with response to contrasting environments had no direct influence on crop yields (p > 0.05) for all the genotypes except PM 14-11. Results revealed that the south zone environment initiated early flowering and an extended reproductive period, thus sustaining yield with good seed size. While in low rainfall areas viz., Sriganganagar, New Delhi, Durgapura, and Sagar, the yield was comparatively low irrespective of genotypes. Correlation results and PCA indicated that rainfall during the crop season and relative humidity significantly and positively influenced grain yield. Hence, the present study suggests that the yield potential of mungbean is independent of crop phenological dynamics; rather, climatic variables like rainfall and relative humidity have considerable influence on yield. Further, HA-GGE biplot analysis identified Sagar, New Delhi, Sriganganagar, Durgapura, Warangal, Srinagar, Kanpur, and Mohanpur as the ideal testing environments, which demonstrated high efficiency in the selection of new genotypes with wider adaptability. Copyright © 2022 Parihar, Gupta, Hazra, Lamichaney, Sen Gupta, Singh, Kumar, Singh, Vaishnavi, Jaberson, Das, Dev, Yadav, Jamwal, Choudhary, Khedar, Prakash, Dikshit, Panwar, Katiyar, Kumar, Mahto, Borah, Singh, Das, Patil, Nanda, Kumar, Rajput, Chauhan, Patel, Kanwar, Kumar, Mishra, Kumar, Swarup, Mogali, Kumaresan, Manivannan, Gowda, Pandiyan, Rao, Shivani, Prusti, Mahadevu, Iyanar and Das.
Nitrogen conservation efficiency of five common riparian weeds in a runoff experiment on slopes
(1992) Raju Kumar; R.S. Ambasht; N.K. Srivastava
The role of five herbaceous riparian weeds, namely Leonotis nepetaefolia (L.) R. Br., Cassia tora L., Ageratum conyzoides L., Parthenium hysterophorus L. and Sida acuta burm f., in reducing runoff and nitrogen losses has been studied. Seedlings of the species collected from the banks of the Rihand River and the Rihand Reservoir (Pant Sagar) were transplanted on sloping experimental plots in the Botanical Garden, Banaras Hindu University. A simulated total rainfall equal to 42·5 mm at an intensity of 30 cm/h was applied for 8·5 min on each of the five vegetated plots and on an equal sized bare plot. Water and soil running down the sloping plots were separately collected in cemented reservoirs. They were analysed for different forms of nitrogen. Conservation values (CV) of soil, water and nitrogen were calculated using the method described by Ambasht (1970). Soil CV ranged from 33% to 84% and water CV from 19% to 50% for different species. Total nitrogen, ammonia nitrogen and nitrate nitrogen CV of five species ranged from 26% to 63%, 50% to 82%, and 51% to 88%, respectively. By stepwise multiple regression, it is found that canopy was the single most important factor (up to 69%) in explaining variations in runoff. © 1992 Academic Press Limited.
Prevalence of cases of amebic liver abscess in a tertiary care centre in India: A study on risk factors, associated microflora and strain variation of Entamoeba histolytica
(Public Library of Science, 2019) Aradhana Singh; Tuhina Banerjee; Raju Kumar; Sunit Kumar Shukla
Background Amebiasis, caused by Entamoeba histolytica (E. histolytica), is a significant cause of morbidity and mortality in developing countries. Mortality due to amebiasis is mostly by extra intestinal infections, amebic liver abscess being the most common one. This study was conducted to determine the current epidemiological status, risk factors, associated microflora and strain variation of E. histolytica causing liver abscesses. Methods/Findings A total of 115 liver abscess cases comprising of 107 (93%) males and 8 (6.9%) females were included in the study. Microscopic examination of pus samples from the abscesses and species discrimination using nested multiplex PCR showed the presence of E. histolytica in 101 (87.5%) cases. Data collected by face to face interviews using a pre tested questionnaire suggested intake of untreated drinking water (ORs: 6.4, p = 0.002), habit of alcohol consumption (ORs: 4.0, p = 0.019) and lack of urban services (ORs: 0.08, p = 0.017) to be major risk factors associated with E. histolytica infections. The study of associated bacterial flora through aerobic culture of liver aspirates and conventional PCR for detection of anaerobes revealed the presence of Fusobacterium (19, 25.5%), Peptococcus (19, 25.5%), Prevotella (18, 24.3%), Bacteroides (8, 10.8%), Staphylococcus aureus (3, 4%), Escherichia coli (2, 2.7%), Peptostreptococcus (2, 2.7%), Clostridium (2, 2.7%) and Klebsiella pneumoniae (1, 1.3%). Further to study the clonality, genotyping of E. histolytica targeting six tRNA-linked polymorphic STR loci (A-L, D-A, N-K, R-R, STGA -D and S-Q) was carried out which showed the presence of 89 different genotypes in the liver aspirate samples. Conclusion The findings highlight the high prevalence of genetically diverse E. histolytica from the liver abscess cases in this geographical region. Low socio-economic status and habit of alcohol consumption were important predictors of amebic liver abscess. © 2019 Singh et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Reduction of nitrogen losses through erosion by Leonotis nepetaefolia and Sida acuta in simulated rain intensities
(1997) Raju Kumar; R.S. Ambasht; Ajit Srivastava; N.K. Srivastava; A. Sinha
Leonotis nepetaefolia, a tall herb and Sida acuta a medium size herb were selected to experimentally test the efficacy of vegetal cover in conservation of soil, water and nitrogen under varying intensities of simulated rain. Young seedlings of the species collected from the banks of the Rihand River, about 150 km South of Varanasi, India, were transplanted on sloping experimental plots. Simulated rainfall of 20, 25, 31, 38, 46 and 55 mm h-1 was applied for 50 min on the two vegetated and one bare plot. Water and soil running down from each of the sloping plots were collected separately in respective cemented reservoirs. They were analysed for different forms of nitrogen. The conservation value (Cv) of soil, water and nitrogen were calculated using Ambasht's formula. Depending upon the nature of vegetation protecting the surface, soil loss through erosion increased two to three times on doubling the rain intensity. As the rain intensity was raised soil conservation value of Leonotis increased from 63 to 88% and of Sida from 27 to 57%. Leonotis with better ground cover reduced particulate nitrogen erosion more effectively. The major fraction of nitrogen (total-N, ammonia-N and nitrate-N) transport down the slope was in soluble form.
Role of some riparian wetland plants in reducing erosion of organic carbon and selected cations
(Elsevier B.V., 1996) Raju Kumar; R.S. Ambasht; Ajit K. Srivastava; N.K. Srivastava
Five riparian herbaceous plants, Leonotis nepetaefolia, Cassia tora, Ageratum conyzoides, Parthenium hysterophorus and Sida acuta, dominant on the banks of the Rihand river at Renukoot (India), were selected to assess experimentally their quantitative role in conserving organic-C, Na, K and Ca. Young seedlings from the river bank were planted on sloping experimental plots made of alluvial soil. Simulated rainfall totalling 42.5 mm was applied at 300 mm h-1 on five vegetated and one bare plots. Runoff water and eroded soil were collected from each experimental plot in artificial reservoirs and their quantities were measured. The soil conservation value of the five selected species ranged between 33 and 84% while the water conservation value varied between 19 and 50%. The overall nutrient conservation value, based on the losses in runoff water and eroded soil taken together, varied from 30 to 83% for organic-C, 19 to 78% for Na, 13 to 72% for K and 29 to 52% for Ca under different species. Loss of these four nutrients in response to 42.5 mm simulated rainfall was much higher than their input through rainfall. Loss value for the nutrients were in following order: organic-C > Ca > K > Na. The fraction of organic-C transported down the slope was higher in eroded soil (averaging 73%) and of exchangeable bases in runoff water (averaging 86% for Na, 82% for K and 90% for Ca). Flow-weighted concentrations of all the studied nutrients were consistently greater from bare stands. Number of fine roots was found to play greater role in the case of organic-C (92%; p < 0.01) and Na (70%; p < 0.05) runoff and their conservation by different plant species but canopy cover played greater role for K (58%; p < 0.08) and Ca (90%; p < 0.01).