263 research outputs found

    Influence of different transplanting date and weed management practices on yield and quality of basmati rice (Pusa Basmati-1509)

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    A field experiment was conducted during kharif 2014 at students’ farm of Chaudhary Charan Singh Haryana Agricultural University, college of agriculture, Kaul (Kaithal). The experiment consisted of four transplanting dates (June 15, July 5, July 25 and August 15) in main plots and six weed control treatments in sub plots treatments consisted of pre-emergence application of pretilachlor, oxadiargyl alone and sequential application of pre and post emergence herbicides viz., pretilachlor fb bispyribac, oxadiargyl fb bispyribac, weed free check and unweeded check. Based on research investigation it was observed that early transplanting dates (June 15 and July 5) produced taller plant, higher tillers/m2 and crop dry matter accumulation at all growth stages. Early transplanting produced significantly higher number of effective tillers/m2 (263) along with higher number of filled grain/ panicle (85) than delayed planting (July 25 and August 15). The 1000-grain weight was not affected by time of transplanting. The highest grain yield (4363 kg/ha) was recorded under June 15 transplanting which was statistically at par to the grain yield (4058 kg/ha) obtained under July 5 transplanting. Among the weed management practices tried, weed free check resulted in the highest values of plant height (104.2 cm), tillers/m2 (305), crop dry matter accumulation (964 g/ m2), effective tillers/m2 (271), grains length (8.5 cm), filled grains/panicle (86.3) as well as grain (4516 kg/ha) and straw yield (5506 kg/ha) which were however, comparable to pre-emergence application of oxadiargyl followed by bispyribac-sodium applied at 25 DAT and pretilachlor followed by bispribac-sodium at 25DAT

    Jet propagation and the asymmetries of CSS radio sources

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    As Compact Steep Spectrum radio sources have been shown to be more asymmetrical than larger sources of similar powers, there is a high probability that they interact with an asymmetric medium in the central regions of the host elliptical galaxy. We consider a simple analytical model of the propagation of radio jets through a reasonable asymmetric environment and show that they can yield the range of arm-length and luminosity asymmetries that have been observed. We then generalize this to allow for the effects of orientation, and quantify the substantial enhancements of the asymmetries that can be produced in this fashion. We present two-dimensional and three-dimensional simulations of jets propagating through multi-phase media and note that the results from the simulations are also broadly consistent with the observations.Comment: 11 pages, 6 figures, 1 table, accepted for publication in A&

    Multivariate analysis of pearl millet data to delineate genetic variation

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    Loss of biodiversity not only disturbs the process of plant development aimed at genetic amelioration but also disrupts the fundamental services that ecosystems provided to humanity. Assessment of variability is a multidimensional problem. The multivariate statistics can help in a comparative assessment of genetic variability. A set of 66 lines of pearl millet was analyzed for cluster and principal component analysis (PCA). PCA identified six principal components which explained 77.7 per cent of total variability among the 66 genotypes. The PC1 characters –main ear weight, dry fodder weight, total ear weight, grain yield, growth rate and plant height, the major characters of plant biomass and the basis for grain yield contributed maximum 35.94 per cent variability among the lines. The remaining PCs accounted for progressively lesser and lesser amount of variability. The lowest contribution 5.27 per cent was recorded by PC 6, the characters grain starch, starch recovery and ear girth. Only grain starch contributed positively to all the six components. The genotypes 50 (77/371), 3 (IPC-115), 41 (204/2 MP), 12 (IPC-1462), 37 (TCH-37-1), 22 (TCH-10-1), 61 (1307), 14 (862-P2), 20 (TCH-3-2), 40 (204-2-3) were found to be better performers and diverse on the basis of principal factor scores with regard to grain yield and yield contributing characters. Hierarchical cluster analysis grouped 66 genotypes into six clusters, cluster 1 included maximum number of 21 genotypes and clusters 3 and 6 had the lowest number of 6 genotypes. The results on hierarchical cluster analysis almost mimicked the PCA. The grouping pattern of genotypes obtained by cluster analysis and PCA plots was almost similar. A wide range of diversity for most of the traits observed would enable to pick lines with suitable traits to be used in a breeding programme. Genetic diversity was not essentially associated with geographic diversity

    Trends in the recovery of phosphorus in bioavailable forms from wastewater

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    Addressing food security issues arising from phosphorus (P) scarcity is described as one of the greatest global challenges of the 21st Century. Dependence on inorganic phosphate fertilisers derived from limited geological sources of P creates an urgent need to recover P from wastes and treated waters, in safe forms that are also effective agriculturally – the established process of P removal by chemical precipitation using Fe or Al salts, is effective for P removal but leads to residues with limited bioavailability and contamination concerns. One of the greatest opportunities for P recovery is at wastewater treatment plants (WWTPs) where the crystallisation of struvite and Ca-P from enhanced biological P removal (EBPR) sludge is well developed and already shown to be economically and operationally feasible in some WWTPs. However, recovery through this approach can be limited to <25% efficiency unless chemical extraction is applied. Thermochemical treatment of sludge ash produces detoxified residues that are currently utilised by the fertiliser industry; wet chemical extraction can be economically feasible in recovering P and other by-products. The bioavailability of recovered P depends on soil pH as well as the P-rich material in question. Struvite is a superior recovered P product in terms of plant availability, while use of Ca-P and thermochemically treated sewage sludge ash is limited to acidic soils. These technologies, in addition to others less developed, will be commercially pushed forward by revised fertiliser legislation and foreseeable legislative limits for WWTPs to achieve discharges of <1 mg P/L

    Inheritance study and stable sources of maydis leaf blight (Cochliobolus heterostrophus) resistance in tropical maize germplasm

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    Maydis leaf blight (MLB), a serious foliar fungal disease of maize, may cause up to 40% losses in yield. The present studies were undertaken to identify the stable sources of MLB resistance, its inheritance study, and testing of MLB resistance linked markers from diverse background in the Indian adapted tropical maize genotypes. A set of 112 inbred lines were screened under artificially created epiphytotics conditions at three hotspot locations. Analysis across multi-locations revealed significant effects of genotypes and environments, and non-significant effects due to genotypes × environment interaction on disease incidence. A total of 25 inbred lines with stable resistance were identified across multi-locations. Inheritance of resistance was studied in six F1s and two F2s of resistant and susceptible parents. The null hypothesis of segregation of resistance and susceptible for mono and digenic ratios in two F2 populations was rejected by Chi-square test. The non-significant differences among the reciprocal crosses depicted the complete control of nuclear genome for MLB resistance. Partial dominance in F1s and normal distribution pattern in F2s of resistant and susceptible parents suggested polygenic nature of MLB resistance. Correlation studies in F2 populations exhibited significant negative correlation between disease score and days to flowering. Five simple sequence repeats (SSRs) markers, found associated to MLB resistance in different studies were unable to differentiate amongst MLB resistance and susceptible parents in our study. This emphasizes the need of fine mapping for MLB resistance in Indian germplasm. The identified stable sources of resistance and information on inheritance study can be used further in strengthening of resistance breeding against MLB

    FOREST CANOPY DENSITY ASSESSMENT USING HIGH RESOLUTION LISS-4 DATA IN YAMUNANAGAR DISTRICT, HARYANA

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    Forest plays an important role not only in providing ecological services but also economic goods to human beings. However, with increase in population there is a wide gap between demand and supply of these goods and services. This has lead to reduction in forest cover which needs to be taken care on regular time interval. To manage the existing forest area and also to increase the forest cover Forest Canopy Density (FCD) methodology is the main factor which was given by International Tropical timber Organization (ITTO). High resolution remote sensing LISS-4 data gives us chance to assess the quality of forest in terms of FCD as Rikimaru et al (1999) stated that FCD is one important parameter to assess forest cover quality. High resolution LISS-4 data analysis for FCD was never attempted before. Authors here attempted to assess the FCD utilizing methodology adopted by Rikimaru (1999), Huang (2001), Azizia (2008). The adopted methodology is one of the most efficient and cost effective way to derive the FCD. For this study Resourcesat-2 LISS-4 post monsoon data of year 2017 for Yamunanagar district was used to assess FCD within notified forest boundary. Notified forest boundaries at cadastral level prepared previously by Haryana Space Applications Centre (HARSAC) was used. The degree of forest canopy density is expressed in percentages: i.e. < 10% FCD (scrub land), 10–20% (Open Forest-I), 20–40% (Open Forest-II), 40–60% (Moderate Dense), 60–80% (Medium Dense) and > 80% (Highly Dense). Forest Canopy Density was based on three indices i.e. Advanced Vegetation Index (AVI), Bare Soil Index (BSI) and Canopy Shadow Index (CSI). Accuracy assessment was done based on ground data and comparison with Coterminous Google Earth imagery and it was found that the devised methodology has achieved overall accuracy of 93% with kappa coefficient of 0.9153. The result shows that maximum forest area in Yamunanagar district is in medium dense FCD category which is approximately 23948.08 acres. This study tells us that 24.2% of the total forest area is under scrub land and open forest which should be focussed for activities in working plan to increase the forest cover. This paper highlights the utility of high resolution satellite data for monitoring and management of forest and improvement in its quality. This attempt provided large scale (1 : 10,000) maps to the forest managers to better equip them in planning for afforestation, reforestation and rehabilitation of water logged areas, environment management and their future aspect

    Biplot analysis of genotype × environment interactions and identification of stable sources of resistance to Ascochyta blight in chickpea (Cicer arietinum L.)

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    Ascochyta blight (AB) caused by Ascochyta rabei (Pass.) Labr. is one of the most important constraints that limits the productivity of chickpea (Cicer arietinum L.). The absence of high levels of stable resistant sources to the pathogen has necessitated the continued search and identification of new sources of resistance. The main aim of this work was to identify new sources of resistance to AB and validate their stability across multi-environments. A collection of 424 elite chickpea genotypes were evaluated for AB resistance under controlled environmental conditions in 2005–2006 at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India. Fifty-one genotypes with AB severity ≤3.0 (based on the 1–9 scale) were selected for a second round of evaluation in 2006–2007 at ICRISAT. Based on the results obtained during both years, an Ascochyta Blight Nursery (ABN) was established to evaluate the selected 29 chickpea genotypes, including 4 germplasm lines, 24 breeding lines and a highly susceptible line. The nursery was evaluated at 3 locations (Almora, Dhaulakuan and Ludhiana) in India over three crop seasons (2007–2008, 2008–2009 and 2009–2010) and under controlled environment conditions at ICRISAT to further confirm the stable performance of these genotypes. Analysis of variance revealed highly significant effects of year, location (year), genotype and genotype × location (year) interaction. The genotype and genotype × environment (GGE) biplot analyses of multi-environment data showed that resistance of five genotypes (EC 516934, ICCV 04537, ICCV 98818, EC 516850 and EC 516971) had mean disease severity ≤3.0 on the 1–9 scale and the reactions were consistent across the environments. Genotype EC 516934 was found resistant to AB at the seedling stage in the controlled environment at ICRISAT. The remaining genotypes showed moderately resistant reaction (3.0–5.0) to AB under controlled environment conditions. A significant positive correlation was found between the performance of the genotypes under controlled environment and field screening conditions (r = 0.70; P < 0.01). The resistant genotypes identified in the present study would be useful in breeding programs as stable resistant donors to evolve agronomically desirable AB resistant varietie
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