Cent Contribution Research Articles

Investigating the friction coefficient in functionally graded rapid prototyping of Al–Al2O3 composite prepared by fused deposition modelling

PurposeThe present research work aims to study the friction coefficient in functionally graded rapid prototyping of Al–Al2O3 composite prepared via fused deposition modelling (FDM)-assisted investment casting (IC) process. The optimized settings of the process parameters (namely, filament proportion, volume of FDM pattern, density of FDM pattern, barrel finishing (BF) time, BF media weight and number of IC slurry layers) suggested in the present research work will help fabricate parts possessing higher frictional coefficient.Design/methodology/approachInitially, melt flow index (MFI) of two different proportions of Nylon6-Al–Al2O3 (to be used as an alternative FDM filament material) was tested on the melt flow indexer and matched with MFI of commercially used acrylonitrile–butadiene–styrene filament. After this, the selected proportions of Nylon6-Al–Al2O3 were prepared in the form of the FDM filament by using a single screw extruder. Further, this FDM filament has been used for developing sacrificial IC patterns in the existing FDM system which was barely finished to improve their surface finish. Castings developed were tested for their wear resistance properties on a pin-on-disc-type tribo-tester under dry conditions at sliding conditions to check their suitability as a frictional device for industrial applications. In the methodology part, Taguchi L18 orthogonal array was used to study the effect of selected process variables on the coefficient of friction (μ).FindingsIt has been found that filament proportion, volume of FDM pattern and density of FDM pattern have significantly affected the μ-values. Further, density of the FDM pattern was found to have 91.62 per cent contribution in obtaining μ-values. Scanning electron micrographs highlighted uniform distribution of Al2O3 particles in the Al-matrix at suggested optimized settings.Practical implicationsThe present methodology shows the development of a functional graded material that consisted of surface reinforcement with Al2O3 particles, which could have applications for manufacturing friction surfaces such as clutch plates, brake drum, etc.Originality/valueThis paper describes the effect of process parameters on wear properties of the Al–Al2O3 composite developed as a functionally graded material by the FDM-based pattern in the IC process.

Analysis of rainfall by using Mann-Kendall trend, Sen’s slope and variability at five districts of south Gujarat, India

On the basis of past 115 years (1901-2015) rainfall data of five districts of south Gujarat, the Mann-Kendall trend, Sen’s slope and regression slope showed that annual and monsoon rainfall at Valsad, Dang and Surat shows the increasing trend while, that of Navsari and Bharuch districts are declining. The monsoon season (summer monsoon) rainfall variability of Valsad, Dang, Surat, Navsari and Bharuch districts was recorded is 30.1%, 30.9%, 35.9%. 33.3% and 38.6%. The high coefficient of variation (CV) denoted that the variability of rainfall is not equally distributed and the amount of rainfall is lowest. The Bharuch district the annual and monsoon CV per cent denoted that the variability of rainfall in both seasons are very high. Valsad was recorded lowest CV with highest rainfall while the data are represent that variability of rainfall which can varies Bharuch to Dang in different districts of south Gujarat. The data shows that Dang district comes under high rainfall and Bharuch under low rainfall on south Gujarat. A low standard deviation indicates that the data points tend to be close to the mean of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values. Similarly high SD is reported at Dang district because of high range of rainfall and lowest SD is found at Bharuch district because of low rainfall variability. The rainfall distribution different season viz., pre monsoon, monsoon post monsoon and winter season, the highest present contribution of rainfall is observed during monsoon season followed by post monsoon in all the five districts of south Gujarat. Rainfall contribution during remaining months was less than one per cent. While month wise analysis shows during monsoon season highest rainfall per cent contribution to annual rainfall is in July followed by August and June months at all the five districts of south Gujarat.

Effect of plant density and foliar nutrient application on seed yield and quality in Asiatic carrot (Daucus carota)

A field experiment was conducted to study effect of plant density and foliar spray of nutrients on carrot (Daucus carota L.) seed yield and quality during winter season of 2012-13 and 2013-14. Plant height, days to 50% flowering, number of umbels/plant, number of seeds/umbel, seed yield/umbel, percentage contribution of different order umbel to total seed yield, seed yield/plant, seed yield/ha, 1 000 seed (mericarp) weight, germination (%) and vigour index were recorded. Significant highest average plant height, earliness in days to 50% flowering and seed yield/ha (12.9 q) were observed in high plant density (13 plants/m2). More number of secondary (11.6) and tertiary umbels (30.1) and higher seed yield/plant (25.2g) were recorded in low plant density (4 plants/m2). Per cent contribution of primary umbel to total seed yield was maximum (41.76%) in 13 plants/m2 and minimum (16.89%) in 4 plants/m2. But an increasing trend in contribution percentage to total seed yield by secondary and tertiary umbels was recorded from 13 plants/m2 to 4 plants/m2.Seeds from primary and secondary umbels recorded high quality in plant density of 5 plants/m2 and 4 plants/m2 respectively.Comparative reduction in pooled seed vigour was observed in 7 plants/m2 and 13 plants/m2. Foliar spray of 0.1% MgSO4at 30 and 60 days after transplanting (DAT) increase the seed quality. Both seed yield and qualityincrease was observed in 0.1% borax spray at 30 and 60 DAT.

Growth dynamics and acreage response of paddy in eastern Vidarbha zone of Maharashtra

The present study entitled Acreage response of paddy in eastern Vidarbha (M.S.) was undertaken to know rate of growth in area, magnitude of instability, correlation, acrage response, price elasticity of paddy. The study has been undertaken in eastern Vidarbha zone. Data pertains for the year 1984-2014. The decomposition analysis model (Minhas, 1964) and regression model of the Nerlovian lagged adjustment model (1958) was used in the present study. The following conclusions were drawn from the study. The growth rate for area and production under paddy has increased in all the districts of eastern Vidarbha region of Maharashtra for the study period. The area, production and productivity instability in paddy was observed in almost all districts in the state. It may be because the crop largely depends on vagaries of nature which causes heavy losses. Per cent contribution of area effect was more responsible for paddy production in the initial period but later yield effect was more pronounced. In the overall period of 30 years, area effect and interaction effect showed proportional share (177.59 % and 54.79 %, respectively) in the Bhandara district. The lagged acreage variable was found significant in Bhandara and Gadchiroli districts of eastern Vidarbha mostly with 5 per cent level of significance. The current year acreage was influenced by farm harvest price nor by one year lagged yield of the paddy in all the districts. The regression co-efficient for lagged area was positive and statistically significant in two districts indicated more rigidity in the adjustment of area under paddy. Long run price elasticities were more than short run elasticities in paddy indicating that farmers was not market oriented in short run period.

Application of path analysis for contribution of reproductive traits in lactation milk yield of half breed cattle

The use of the path co-efficient analysis methodology in half breed cattle revealed that, the reproductive trait- lactation length (LL) had appreciable effect in total lactation milk yield (LMY). Correlation of LL with total LMY was highly significant ranges from 0.267 to 0.522. Direct effect of LL and indirect effects of SP and CI through LL were positive and higher in all lactations. The direct per cent contribution of LL in LMYwas 13.49 to 29.25 per cent. However, SP and CI showed negligible direct contribution in LMY upto 3 rd lactation and for 4 th to 6 th lactation ranged from 4.887 to 14.276 and 5.189 to 22.903 in LMY.AFC showed significant and negative correlation with LMY. Its direct effect also negative and indirect effects through other traits were negligible in LMY.That indicates early age of first calving increases the LMY in different lactations. Therefore, it is suggested that more emphasis may be given on these traits (AFC, SP, CL and LL) for future breeding programme.

Clerics and Scriptures: Experimentally Disentangling the Influence of Religious Authority in Afghanistan

This article unpacks the psychological influence of a Muslim cleric’s power to mobilize for collective action in an experiment in Afghanistan. The same cleric requests contributions for a hospital from day laborers when dressed as a civilian and as a cleric. InCiviliancondition, 50 per cent contributed and 17 per cent made large contributions; inClericcondition, 83 per cent contributed but average giving did not increase as most gave the smallest possible amount. Inclusion of a recitation of Qur’anic verses in theClericcondition maintains the 82 per cent contribution rate while increasing large contributions to 30 per cent, doubling average contributions. Formal education and subjective perception of poverty appear to drive the opposing effects of cleric and scripture. These results suggest that the power to activate spiritual channels lies in the scripture, not with the human wielding religious authority, who instead appears to induce minimal compliance with Islamic norms of charitable giving.

Response of cluster bean (Cyamopsis tetragonoloba L. Taub.) cultivars todual inoculation with fixing and phosphorous solubizing bacteria

A field experiment was conducted at Regional Station, PAU, Bathinda, to investigate the impact of dual inoculation with N fixing and phosphorous solublizing bacteria with different fertility levels on performance of cluster bean cultivars during Kharif 2013 and 2014. The experiment was laid out in randomized complete block design, keeping combination of four cultivars (RGC 936, HG 563, RGC 1003 and RGC 1066) and three fertility levels (Recommended inorganic nutrition 20 kg N and 47.5 kg P2O5/ha, 75 % recommended inorganic nutrition + Rhizobium + phosphorous solublizing bacteria inoculation and 50 % recommended inorganic nutrition + 50 % N through farm yard manure). Guar cultivar RGC 1066 produced maximum seed and dry fodder yield which was statistically at par with RGC 1003 and HG 363 but significantly superior than RGC 936. Plant height and pods/plant were also maximum in RGC 1066 and at par with RGC 1003 and HG 563 but significantly superior over RGC 936. Among the fertility levels, yield attributes and seed yield did not differ significantly except the 50 % flowering and dry fodder yield. Dry fodder yield was significantly higher in plots where 50 % N was substituted with farm yard manure than 25 % inorganic nutrition substituted with inoculation with Rhizobium + PSB and 100 % recommended inorganic fertilized plots. Path coefficient analysis revealed that days to 50 % flowering (DTFF) and pods/plant (PPP) had positive direct effect on Seed yield (SY) with path coefficient of 2.270 and 1.119 at contribution of 38.48 and 19.77 per cent of the total effects, respectively. The direct effect of plant height (PH) on seed yield (SY) was comparatively larger but negative at coefficient value of -2.459 with 41.66 per cent contribution which resulted in significant correlation (r=0.985).

A scientometric analysis of DESIDOC Journal of Library & Information Technology (2010-2014)

Purpose This paper aims to perform a scientometric analysis of DESIDOC Journal of Library and Information Technology (DJLIT) to find out the quality, popularity and impact of the international journal published by DESIDOC. Design/methodology/approach Scientometric analysis of five volumes (from Volume No. 30 to 34) from the year 2010 to 2014 of DJLIT covering 30 issues containing 307 contributions was performed. All the bibliographic details were noted and recorded in tabular form for the purpose of in-depth analysis. Based on the analysis of the recorded data, findings have been presented. Findings The study shows a trend of gradual growth in contributions published during the period of study, with an average number of 61 contributions per volume of the journal. Maximum number of contributions/research papers (70) were found to be published in the year 2012, whereas the minimum (50) in the year 2010. The study reveals that DJLIT gives maximum importance to the original research papers for the purpose of publishing, which attained top position of publications with a total of 277 (90.23 per cent). A maximum number of contributions during the period of study are from joint authors, with a total of 188 (61.24 per cent). Maximum number of contributions are from India, with a total of 273 (88.93 per cent). New Delhi, Maharashtra and Karnataka were found to be the biggest domestic contributors during the period of study, with 68 (24.91 per cent), 39 (14.29 per cent) and 30 (10.99 per cent) contributions, respectively. It appears that the coverage of DJLIT, even being an international journal in the field of library and information science (LIS), is not very broad and its scope is broadly confined to India only. Majority of the authors preferred journals as their major source of information, providing the highest number of citations totaling 2,447 (51.89 per cent), while websites attained the second position with 1,015 (21.52 per cent) citations, followed by books with 613 (13 per cent) citations. The study further reveals that maximum number of citations totaling 1,109 (23.52 per cent) out of 4,716 were received in the year 2013, while least citations totaling 700 (14.84 per cent) were recorded in the year 2010. One of the most important quality of DJLIT is that it has great concern for emerging and new tools, techniques and technologies in the LIS profession and their impact and application in the field. The journal regularly publishes special issues in every volume on such themes that have great impact on the LIS profession, and it has published 16 special issues on various important themes during the period of study. DJLIT, having free online access through the internet, is the highly preferred journal for communication, knowledge acquisition and reference by the LIS professionals. The journal has great potential of attaining new heights of popularity and impact all over the world in the LIS profession. It is suggested that the journal should try to get high-quality papers from foreign authors too, which may be useful in enhancing its global impact and reputation. Research limitations/implications The present study is confined to the data collected from 30 issues of the five volumes of the DJLIT from the year 2010 to 2014, while the journal is continuously being published since the year 1981. Hence, the results may vary if the studies of different blocks of the years of publication of the journal are performed. The present study may not be fully representative in all the results, but it gives a trend regarding publication of the DJLIT. Originality/value Scientometric analysis of journals has been attempted in very few numbers. Hence, the present study will be a source of idea to other researchers.

Genetic variability and divergence studies in cluster bean(Cyamopsis tetragonoloba L.) under hill zone of Karnataka, India

Eighteen genotypes of cluster bean [Cyamopsis tetragonoloba (L.) Taub] were evaluated to estimate variability, broad sense heritability, genetic advance over mean and diversity for vegetable pod yield and related attributes, during summer 2014-15. Maximum range of variability was observed for number of vegetable pods per plant, number of clusters per plant and pod yield. High heritability coupled with high genetic gain in percentage was observed for number of pods per plant, number of clusters per plant, pod yield and days to first flowering. The maximum intra cluster distance was observed in cluster I and intercluster distance was high between cluster I and cluster III, this indicated wide range of variability among clusters. The per cent contribution towards genetic diversity was high for dry pod yield per plant (29.41%) followed by number of dry pods per plant (24.18%) and seed yield per plant (16.99 %).

Growth and carbon stock assessment in three year old fast growing trees grown under wasteland condition at Sivagangai district of Southern Tamil Nadu

A field experiment was conducted to assess the growth and carbon sequestration potential of five fast growing trees namely Tectona grandis, Gmelina arborea, Dalbergia sissoo, Bambusa vulgaris var. vulgaris and Swietenia macrophylla. The saplings of these five species were planted and assessed for biometric, biomass production and carbon accumulation potential. Among the five tree species, Dalbergia sissoo and Bambusa vulgaris var. vulgaris were found to be superior interms of maximum height, basal diameter, biomass and biomass carbon. Gmelina arborea exhibited low height, basal diameter, biomass and biomass carbon. The per cent contribution of biomass carbon was higher in the stems of all the species followed by root, branches and leaves. The field study inferred that, Dalbergia sissoo and Bambusa vulgaris var. vulgaris performed well with higher biomass and biomass carbon productivity under dry land condition and hence these two species can be promoted for afforestation / reforestation of the wastelands in Tamil Nadu under protected irrigation conditions.

Strategies to Accelerate Manufacturing Growth in India: A System Dynamics–Interpretive Structural Modelling Analysis

The stagnant manufacturing sectoral share in India’s gross domestic product (GDP) needs an in-depth understanding, analysis and recommendation for growth. Taking manufacturing to a higher growth trajectory has now become a necessity for India’s prosperity. The 2011 National Planning Commission’s (NMP) objective of 25 per cent contribution by manufacturing to India’s GDP by 2025, though challenging, needs an urgent focus. This article utilizes system dynamics (SD)-based simulation for three futuristic economic scenarios to assess the achievability of the NMP targets. The article also provides an understanding of a few critical issues of the manufacturing sector using the causal loop diagram approach of SD. The article also applies the interpretive structural modelling approach to 19 factors identified from the literature, which impact the manufacturing sector. Nine driving factors have been identified for accelerating the manufacturing sector: Technology, labour Reforms, Infrastructural and energy reforms, Good Governance, quality Education and Resource management (TRIGGER). The four dependent factors identified are Domestic value addition, Macroeconomic health, manufacturing Investment and Green-field projects (DMIG).

Basic corporate governance models: a systematic review

Purpose– The purpose of this paper is to review the state of existing literature for various corporate governance models by answering specific questions. Much has been written in the recent years on various corporate governance (CG) models, primarily the model of Anglo-Saxon and Continental European. In particular, it investigates most examined model in literature, forums used to publish and research types conducted, as well as basic differences between the two models. Findings of this paper suggest that more evidence-based systematic reviews on various aspects and geographical regions are needed to map the entire field of CG.Design/Methodology/Approach– Much has been written in the recent years on various CG models, primarily the model of Anglo-Saxon and Continental European. This paper attempts to review the state of existing literature for these models by answering specific questions. In particular, it investigates most examined model in literature, forums used to publish and research types conducted, as well as basic differences between the two models. Findings of this paper suggest that more evidence-based systematic reviews on various aspects and geographical regions are needed to map the entire field of CG.Findings– The authors found that although both models are well-reviewed, Continental European model is mostly explored with 47 per cent contributions as compared to Anglo-Saxon with 45 per cent. Moreover, majority of contributions are based on analytical research in terms of research type (30 per cent) and primarily focus on convergence of models. In addition, some 85 per cent of selected studies are based on theoretical research work, which leads to a significant dearth of empirical studies in the literature.Research limitations/implications– The scope of the paper is limited to two basic models of CG, namely, Anglo-Saxon model and Continental European model in context of specific research questions.Practical/implications– The systematic review on the basic models will assist the practitioners and policy-makers in determining the status of existing literature based on evidences. Further, it may facilitate in formulating new laws, regulations, codes and policies.Originality/Value– The authors used evidenced-based systematic approach for conducting literature review of CG models. Systematic review is getting much attention of researchers, as it minimizes the bias by adopting a replicable, scientific and transparent process. This review, as contrary to narrative, contributes to the CG models literature the findings based on evidences.

Authorship pattern and collaborative research in the field of spacecraft technology

Purpose – The purpose of this paper is to study and analyse the authorship pattern, degree of collaboration, prepare list of prolific authors and test Lotka’s law of scientific productivity in spacecraft technology research. Design/methodology/approach – Data are collected from the print versions of three journals in the field of spacecraft technology for the period 2001-2011. In all 154 volumes containing 1,907 papers have been analysed, and data are presented in different table headings. Findings – Study reveals that 4,355 authors have contributed 1,907 papers. Journal of Spacecraft and Rockets has published maximum (1,487) number of papers during the study period. Multi-authored papers with 87.15 per cent of contributions have dominated this field of research. Journal of Spacecraft Technology has recorded highest degree of collaboration of 0.90. James M. Longuski has published 20 papers in Journal of Spacecraft and Rockets during the period 2001-2011. Lotka’s law of scientific productivity is tested and conforms only partially. Research limitations/implications – Study is restricted only for the period 2001-2011, and the data are collected from the print versions of three journals in the field of spacecraft technology research. Originality/value – As far as space science and technology is concerned, there are not many bibliometric studies reported in the published literature. The present study will add value to the bibliometrics literature and provide publishing trends in spacecraft technology research.

A NuSTAR observation of disc reflection from close to the neutron star in 4U 1608–52

Abstract Studying the reflection of X-rays off the inner edge of the accretion disc in a neutron star low-mass X-ray binary allows us to investigate the accretion geometry and to constrain the radius of the neutron star. We report on a NuSTAR observation of 4U 1608–52 obtained during a faint outburst in 2014 when the neutron star, which has a known spin frequency of ν = 620 Hz, was accreting at ≃1–2 per cent of the Eddington limit. The 3–79 keV continuum emission was dominated by a Γ ≃ 2 power law, with an ≃1–2 per cent contribution from a kTbb ≃ 0.3–0.6 keV blackbody component. The high-quality NuSTAR spectrum reveals the hallmarks of disc reflection; a broad iron-line peaking near 7 keV and a Compton back-scattering hump around ≃20–30 keV. Modelling the disc reflection spectrum points to a binary inclination of i ≃30°–40° and a small ‘coronal’ height of h ≲8.5GM/c2. Furthermore, our spectral analysis suggests that the inner disc radius extended to Rin ≃ 7–10GM/c2, close to the innermost stable circular orbit. This constrains the neutron star radius to R ≲21 km and the redshift from the stellar surface to z ≳0.12, for a mass of M = 1.5 M⊙ and a spin parameter of a = 0.29.

Contribution of water chemistry and fish condition to otolith chemistry: comparisons across salinity environments.

This study quantified the per cent contribution of water chemistry to otolith chemistry using enriched stable isotopes of strontium ((86) Sr) and barium ((137) Ba). Euryhaline barramundi Lates calcarifer, were reared in marine (salinity 40), estuarine (salinity 20) and freshwater (salinity 0) under different temperature treatments. To calculate the contribution of water to Sr and Ba in otoliths, enriched isotopes in the tank water and otoliths were quantified and fitted to isotope mixing models. Fulton's K and RNA:DNA were also measured to explore the influence of fish condition on sources of element uptake. Water was the predominant source of otolith Sr (between 65 and 99%) and Ba (between 64 and 89%) in all treatments, but contributions varied with temperature (for Ba), or interactively with temperature and salinity (for Sr). Fish condition indices were affected independently by the experimental rearing conditions, as RNA:DNA differed significantly among salinity treatments and Fulton's K was significantly different between temperature treatments. Regression analyses did not detect relations between fish condition and per cent contribution values. General linear models indicated that contributions from water chemistry to otolith chemistry were primarily influenced by temperature and secondly by fish condition, with a relatively minor influence of salinity. These results further the understanding of factors that affect otolith element uptake, highlighting the necessity to consider the influence of environment and fish condition when interpreting otolith element data to reconstruct the environmental histories of fish.

Capital investment in cotton production

Vidarbha agricultural economy is based on cotton production. Cotton is the main cash crop grown in Vidarbha. Akola is pre-dominantly known as cotton city of the region. The capital management in cotton production is mostly high labour input oriented and as such the productivity of cotton is below the state average. With this view, the study has been conducted in Akola district to know the inputs used in cotton production, and the share of each input and its contribution in cotton productivity and to study the input-output relationship in cotton production. The study is based on data for the year 2011-12, collected by cost accounting method under agricultural prices and cost scheme. It was concluded that the per cent share of inputs to expenditure was 44.33 per cent of human labour, 19.56 per cent of bullock labour and 15.51 per cent of seed. The contribution of the selected variables in determining productivity was 47.34 per cent of human labour, 13.67 per cent of bullock labour and 32.16 per cent of seed. The relationship between human labour, bullock labour, machine power, seed and manure with productivity was found to be significant. Production function analysis revealed that, decreasing returns to scale (0.78) was observed in cotton production with the value of R2 (0.79), indicating variables under study have explained 79 per cent contribution in cotton production.

Groundwater ‐ the disregarded component in lake water and nutrient budgets. Part 1: effects of groundwater on hydrology

AbstractLake eutrophication is a large and growing problem in many parts of the world, commonly due to anthropogenic sources of nutrients. Improved quantification of nutrient inputs is required to address this problem, including better determination of exchanges between groundwater and lakes. This first of a two‐part review provides a brief history of the evolution of the study of groundwater exchange with lakes, followed by a listing of the most commonly used methods for quantifying this exchange. Rates of exchange between lakes and groundwater compiled from the literature are statistically summarized for both exfiltration (flow from groundwater to a lake) and infiltration (flow from a lake to groundwater), including per cent contribution of groundwater to lake‐water budgets. Reported rates of exchange between groundwater and lakes span more than five orders of magnitude. Median exfiltration is 0.74 cm/day, and median infiltration is 0.60 cm/day. Exfiltration ranges from near 0% to 94% of input terms in lake‐water budgets, and infiltration ranges from near 0% to 91% of loss terms. Median values for exfiltration and infiltration as percentages of input and loss terms of lake‐water budgets are 25% and 35%, respectively. Quantification of the groundwater term is somewhat method dependent, indicating that calculating the groundwater component with multiple methods can provide a better understanding of the accuracy of estimates. The importance of exfiltration to a lake budget ranges widely for lakes less than about 100 ha in area but generally decreases with increasing lake area, particularly for lakes that exceed 100 ha in area. No such relation is evident for lakes where infiltration occurs, perhaps because of the smaller sample size. Copyright © 2014 John Wiley & Sons, Ltd.

Genetic divergence studies in chilli (Capsicum annuumL.) under temperate conditions

The genetic divergence study was conducted in 64 genotypes of chilli (Capsicum annuum L.) for 15 agro-morphological traits. Significant divergence existed among 64 chilli genotypes almost for all the traits. The genotypes under study were grouped into eight clusters as per Mahalanobis D2 (1928) analysis employing Tocher's method with maximum number of genotypes in cluster I (37) followed by cluster IV (12), cluster II (6), cluster V (5) and rest of the clusters were monogenotypic. Maximum intercluster distance was observed between clusters II and VI (19369.21), while maximum intra-cluster distance was observed in cluster IV (4230.34). The per cent contribution towards the total genetic divergence revealed that plant spread (29.76%), seed yield per plant (25.69%), average fruit weight (17.41%), number of fruits per plant (10.22%), days to first flower (4.01%), fruit length (4.76%), number of branches per plant (4.51%) and fruit diameter (2.88%) were the major contributing characters towards total genetic divergence. The crosses between the genotypes from cluster VI with II and VIII and cluster VIII with those of I, III and IV are likely to exhibit high heterosis and produce recombinants with desired traits in segregating generations.

Effect of Weed Control on Performance of Guinea Grass-Legumes Intercropping System under Rainfed Conditions

A field experiment was conducted during 2006–2011 on sandy loam soil at Central Research Farm of Indian Grassland and Fodder Research Institute, Jhansi to study the effect of weed control on performance of Guinea grass-legumes intercropping system under rainfed conditions. Intercropping of Stylosanthes hamata with Guinea grass produced significantly higher total dry forage (5.18 t/ha) than Clitoria ternatea (3.89 t/ha), Macroptillium atropurpureum (4.19 t/ha) and S. seabrana (4.67 t/ha) during 1st year of experiment. While during 2nd, 3rd and 4th years, intercropping of Stylosanthes seabrana with Guinea grass produced significantly higher total dry forage yield (9.56, 6.56 and 6.04 t/ha) than Clitoria ternatea (7.92, 5.23 and 4.49 t/ha), Macroptillium atropurpureum (8.12, 5.34 and 4.76 t/ha) and S. hamata (8.76, 5.97 and 5.26 t/ha). In total dry forage yields, per cent contribution of S. seabrana were 34.90, 31.17, 41.62 and 40.73 during 1st, 2nd, 3rd and 4th years respectively. Crude protein yields (812.3, 587.0 and 538.7 kg/ha) were also increased significantly when guinea grass intercropped with S. seabrana than intercropping with C. ternatea, Macroptillium atropurpureum and S. hamata. In weed management practices, hand weeding 35 days after sowing in 1st year and 25 days after onset of monsoon rain from 2nd year onwards recorded significantly higher dry forage yields of both Guinea grass (3.52, 7.81, 4.53 and 4.21 t/ha) and legumes (1.81, 2.48, 2.15 and 1.72 t/ha) than weedy check, pre-emergence application of pendimethalin @ 0.75 kg a.i./ha and weeding with weeder cum mulcher during 1st, 2nd, 3rd and 4th years, respectively. The Maximum net return ( 4232, 20778, 14532 and 15390/ha) and net return per rupee invested ( 0.38, 2.26, 1.64 and 1.63) were obtained by intercropping of Guinea grass with S. seabrana during 1st, 2nd, 3rd and 4th years of study. Hand weeding 35 days after sowing in 1st year and 25 days after onset of monsoon rain from 2nd year onwards also recorded maximum net return ( 3771, 17053, 9796 and 10183/ha) during all the 4 years.

Soil Test based Fertilizer Prescriptions under Integrated Plant Nutrient Supply for Rice-Rice Cropping Sequence in Inceptisols of Assam

Field experiments were conducted during 2010–12 to assess the fertilizer requirements for rice-rice sequence under integrated plant nutrient supply on Inceptisols (Aeric Endoaquepts) in Jorhat district of Assam. Following Ramamoorthy's Inductive cum targeted yield model, the nutrient requirement per quintal of grain production and contribution from soil, fertilizer and farmyard manure (FYM) were calculated for both autumn and winter rice. The per cent contribution of nutrients from soil (CS), fertilizer (CF) and FYM (CFYM) were found to be 12.49, 45.31 and 32.92 for N, 13.42, 28.52 and 11.84 for P2O5 and 21.99, 47.58 and 29.76 for K2O, respectively for autumn rice. The same for winter rice was 24.60, 33.15 and 48.28 for N, 30.69, 32.15 and 14.38 for P2O5, and 41.00, 56.87 and 31.59 for K2O, respectively. The fertilizer prescription equations were developed and nomograms were formulated based on the equations for a range of soil test values and desired yield target for rice. Under NPK + FYM @ 5.0 t ha−1, 17, 6,14 and 35, 7 and 12 kg ha−1 of fertilizer N, P2O5 and K2O, respectively could be saved for attaining target yield of 40 q ha−1 for autumn rice and 60 q ha−1 for winter rice as compared to NPK fertilizers alone.