147 research outputs found

    Performance of sequential herbicides to control weeds in direct seeded rice

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    Direct seeded rice is an emerging production technology in India due to less requirement of water, labour and capital input initially. But direct seeded rice face severe infestation of weeds. A field experiment was conducted during the kharif 2012 at Students’ Farm of College of Agriculture, CCS Haryana Agricultural University; Kaul campus (Kaithal) to study the performance of sequential application of herbicides on weed flora in direct seeded rice. The herbicidal treatments included two pre emergence herbicides i.e. pendimethalin 1000 g/ha and oxadiargyl 100 g/ ha and four post emergence herbicides (bispyribac sodium 25 g/ha, fenoxaprop 67 g/ha, ethoxysulfuron 18.75 g/ha and metsulfuron methyl 10% + chlorimuron ethyl 10% WP ready mix (Almix) 4 g/ha). Weed free and weedy check were also included. The results showed that grasses were the dominant weed flora (49 %) followed by sedges (34%) and broad leaf weeds (17%).Sequential application of pendimethalin 1000 g/ha fb bispyribac sodium 25 g/ha and metsulfuron methyl + chlorimuron ethyl RM (Almix) 4 g/ha gave significantly lower weed density (p=0.05) and higher weed control efficiency which resulted in more number of effective tillers (209.3), filled grains/panicle (83.7) and grain yield (3.97 t/ha)

    Integrated weed management in direct seeded rice in Trans Indo-Gangetic plains of India- A review

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    In the Indo-Gangetic Plains (IGP) of India, rice (Oryza sativa L.) is taken by conventional tilled puddled transplanted (CT-PTR) method. CT-PTR requires a lot of water (2000-2500 mm) which comes mainly from groundwater. Due to declining water table and changing climate, the sustainability of CT-PTR rice is under immense pressure. The alternative to CT-PTR could be direct seeded rice (DSR) which requires less water, labor, initial cost and energy than CT-PTR. But direct seeded rice is heavily infested with weeds which cause severe loss to the grain yield. Thus, the success of aerobic rice depends on effective and timely weed control. As a single weed control method may not be successful on a long term basis, weed problem in direct seeded rice needs to be solved by integrated approach. Integrating cultural, mechanical and chemical methods along with highly competitive cultivars with effective allelopathic properties, effective weed management on long term sustainable basis can be achieved

    A molecular approach to reveal the genetic identity of parrot mussel and other sympatric mussel species distributed along the Kerala coast

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    Two commercially important mussel species are recorded from the Indian coast: green mussel Perna viridis (Linnaeus, 1758) and brown mussel P. indica (Kuriakose and Nair, 1976). Apart from this, a third type referred to as parrot mussel, which has shell shape of brown mussel, but with green shell colouration and suspected to be the hybrid of the above two species has also been reported from Kollam coast of Kerala, where both the species co-occur. In the present work, genetic identity of parrot and sympatric mussel species was determined using protein and genomic DNA markers. Protein markers viz. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) and allozymes and the genomic DNA marker Random Amplified Polymorphic DNA (RAPD) were used for determining genetic identity of the three mussel groups. The green and brown mussels could be clearly differentiated using SDS PAGE. The parrot mussel protein pattern was similar to that of brown mussel, except for an additional band of molecular weight 48.7 Kda which is unique to brown mussel. Genus specific protein bands for Perna viz. 66 Kda, 43 Kda and 14.3 Kda, were detected in this study. Allozyme electrophoresis also followed a similar pattern. Of the 10 allozyme loci studied, seven revealed speciesspecific diagnostic differences between P.viridis and P.indica. They were AAT-1* (Aspartate Amino Transferase-1*), AAT-2*, ME (Malic Enzyme)*, PGM-2*(Phospo Gluco Mutase-2*), EST-1* (Esterase- 1*), EST-2*, IcDH* (Isocitrate Dehydrogenase)*. Parrot mussel shared all the alleles of brown mussel, and no hybrid pattern was observed. Species-specific alleles clearly differentiated green mussel from both brown and parrot mussel. The genetic distance of green mussel from brown mussel, estimated from allozyme data was 1.1145 and with parrot mussel it was 1.105. The genetic distance between parrot mussel and brown mussel was negligibly low (0.0005). Using allozyme and RAPD data, the Nei’s Unbiased Measures of genetic distance were calculated and the dendograms prepared based on these values clearly depicted the separation of parrot mussel from green mussel as well as the close resemblance of parrot mussel with brown mussel. The higher gene flow (1.1539) determined using RAPD marker also hints that brown and parrot mussel may be acting as single interbreeding population. Hence this study using molecular tools to test the genetic identity of parrot mussel has helped to conclude that parrot mussel is only a morphotype of brown mussel and not a true hybrid of the two

    DNA barcoding Indian marine fishes

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    DNA barcoding has been adopted as a global bio-identification system for animals in recent years. A major national programme on DNA barcoding of fish and marine life was initiated in India by the authors during 2006 and 115 species of marine fish covering Carangids, Clupeids, Scombrids, Groupers, Sciaenids, Silverbellies, Mullids, Polynemids and Silurids representing 79 Genera and 37 Families from the Indian Ocean have been barcoded for the first time using cytochrome c oxidase I gene (COI) of the mtDNA. The species were represented by multiple specimens and a total of 397 sequences were generated. After amplification and sequencing of 707 base pair fragment of COI, primers were trimmed which invariably generated a 655 base pair barcode sequence. The average Kimura two parameter (K2P) distances within species, genera, families, orders were 0.30%, 6.60%, 9.91%, 16.00%, respectively. In addition to barcode-based species identification system, phylogenetic relationships among the species have also been attempted. The neighbour-joining tree revealed distinct clusters in concurrence with the taxonomic status of the species

    Effect of extender composition on sperm cryopreservation of Asian catfish Heteropneustes fossilis (Bloch) and Clarias batrachus (Linnaeus)

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    Air breathing catfish species Heteropneustes fossilis (Bloch) and Clarias batrachus (Linn.) are important table fish and fetch high market price. Cryopreservation of spermatozoa can be a useful tool in captive seed production for domestication and aquaculture of these catfish species. The objective of the present study was to identify optimum extender composition for sperm cryopreservation of the two species, H. fossilis and C. batrachus. Four extender compositions Hank’s Balanced Salt Solution (HBSS), Modified Hank’s Balanced Salt Solution (M-HBSS), Modified Hank’s Balanced Salt Solution with hen’s egg yolk (M-HBSS with EY) and European catfish were evaluated for cryopreservation of catfish sperm and 10 % Dimethyle Sulphoxide (DMSO) was used as a cryoprotectant. The pooled milt exhibiting 70-80% motile sperm was used for cryopreservation experiment. After storage for 48 hrs at -196ºC, the milt was thawed and evaluated for fertility test. The percentage of hatching was used as a parameter for the comparative evaluation of different extender composition. In H. fossilis extender M-HBSS indicated highest hatching rate (49.06%), followed by HBSS (42.76%), M-HBSS with EY (37.46%) and European catfish (29.47%). The hatching success with extender M-HBSS did not differ significantly (P > 0.05) from the control group (51%). In C. batrachus extender HBSS exhibited highest hatching (62.1 %), followed by M-HBSS with EY (51.6%), European Catfish (46.3%) and M-HBSS (40.9%). The hatching rate in control was 90% in C. batrachus. The results indicated that the two species differ in the protocol for sperm cryopreservation. The paper presents successful cryopreservation of sperm with the production of viable hatchlings of H. fossilis and C. batrachus for the first time. The protocol reported in the study can be used for scaling up of seed production of these two catfish species

    Development of new promising varieties of faba bean through traditional pedigree method for commercial cultivation in plain zone of India

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    A long term experiment was carried out in MAP Section, Department of Genetics & Plant Breeding,  CCS Haryana Agricultural University, Hisar from 2005-06 to 2018-19 on identification of elite genotypes from germplasm and their utilization in the development of high yielding variety through hybridization followed by traditional pedigree method to obtain desirable transgressive segregants in Faba bean. In the present investigation a number of germplasm lines were screened for seed yield and other related traits including national check Vikrant during 2005-06 under AICRN in augmented block design. As a result, ten elite genotypes identified i.e. EC117755, EC117799, EC248710, EC329675, HB123, HB180, HB430, HB204, HB 430, HB 502, HB 503 & one check variety, Vikrant. By using these elite genotypes, a number of F1 hybrids were made during 2005-06 and F2 to F6 generations were evaluated to identify the superior progenies during 2007-08 to 2011-12. After a long process of evaluation, rejection and selection, 20 superior transgressive segregant homozygous progenies were identified to make new entries. Later on, during 2012-2013, the superior entries (viz. HB12-1, HB12-5, HB12-8, HB12-9, HB12-11, HB12-12, HB12-13, HB12-14, HB12-15, HB12-26, HB12-28, HB12-29, HB12-30, HB12-31, HB12-34, HB12-36, HB12-37,HB12-38, HB12-39 and HB12-42) were evaluated at Hisar centre against Vikrant and found promising. Therefore, all these 20 genotypes were evaluated in SST during 2013-14, LST during 2014-15 and FYT during 2015-16. On the basis of above results, only five genotypes viz. HB12-8 (47.77q/ha), HB12-42 (47.70q/ha), HB12-15 (46.70q/ha), HB12-34 (46.14q/ha) and HB12-37 (45. 31q/ha) were found promising. These were further evaluated in multi-location trials at seven locations (i.e. Ambikpur, Delhi, Faizabad, Faridkot, Hisar, Ludhiana & Ranchi) for seed yield, quality and resistance against insect pest & disease in IVT and AVT during 2016-17 & 2017-18, respectively. Out of these, HB12-34 exhibited yield superiority over national checks,Vikrant and HFB-1 and free from insect pest and disease as well as low in vicine-covicine and high in protein content. Therefore, HB12-34 may be recommended for commercial cultivation in plain zone at national level

    Cognitive resources moderate the adverse impact of poor perceived neighborhood conditions on self-reported physical activity of older adults

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    Rebar, A ORCiD: 0000-0003-3164-993XPoor neighborhood conditions are associated with lower levels of physical activity for older adults but socio-ecological models posit that physical activity depends on both environmental and individual factors. Older adults' ability to overcome environmental barriers to physical activity may partially rely on cognitive resources. However, evidence on the moderating role of these cognitive resources in the associations between environmental barriers and physical activity is still lacking. We analyzed cross-national and longitudinal data on 28,393 adults aged 50 to 96 years as part of the SHARE. Lack of access to services and neighborhood nuisances were used as indicators of poor neighborhood conditions. Delayed recall and verbal fluency were used as indicators of cognitive resources. Confounder-adjusted generalized estimation equations were conducted to test associations between neighborhood conditions and self-reported moderate physical activity, as well as the moderating role of cognitive resources. Results showed that poor neighborhood conditions reduced the odds of engagement in physical activity. Cognitive resources robustly reduced the adverse influence of poor neighborhood conditions on physical activity. Participants with lower cognitive resource scores showed lower odds of engaging in physical activity when neighborhood conditions were poorer, whereas these conditions were not related to this engagement for participants with higher cognitive resource scores. These findings suggest that cognitive resources can temper the detrimental effect of poor neighborhood conditions on physical activity. Public policies should target both individual and environmental factors to tackle the current pandemic of physical inactivity more comprehensively. © 2019 Elsevier Inc
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