1,720,974 research outputs found
FINANCIAL FEASIBILITY OF LOW FREQUENCY TAPPING SYSTEMS TO DEAL WITH THE BUSINESS CHALLENGE OF RUBBER PLANTATIONS IN INDONESIA
No full textIn present day context, rubber plantations are facing problems of the low rubber price, difficulty in finding workers for tapping and rising the cost of production. Tapping cost is the biggest component in cost of production. Therefore, this study was aimed to analyze financial feasibility of different tapping systems in the mature rubber tapped on B0 panel and H0 B1 panel. Tapping systems comprised varying degree of tapping frequencies and stimulation (ethephon) systems. Financial analysis was based on assessments on the margin revenue and margin costs. Out of 19 tapping systems tested, five systems found to be profitable against the usually practiced once in three day tapping with 2.5% ethephon every two weeks. On the virgin base panel (B0), three systems are available, i.e. two with once in three days tapping using 2.5% ethephon at 10 days interval and 4% ethephon at 2 weeks interval and, another with once in four days tapping using 5% ethephon at 2 weeks interval. In intensified tapping with double cuts (DU), only once in three days tapping was found financially feasible with 4% and 5% ethephon at two weeks intervals on the base panel. Key words :  economic feasibility, partial budget, rubber, tapping system
UJI KETAHANAN KLON KARET IRR SERI 400 TERHADAP BEBERAPA ISOLAT PENYAKIT GUGUR DAUN COLLETOTRICHUM
Get PDFPerakitan klondengan produktivitas tinggi, pertumbuhan jagur, resisten terhadap penyakit gugur daun serta memiliki daya adaptabilitas luas adalah tujuan pemulian karet.Klon IRR seri 400 merupakan calon klon unggul seri IRR berikutnya yang memiliki potensi produksi melebihi klon PB 260.Khusus untuk ketahanan penyakit, pendekatan dengan perakitan klon tahan juga telah dilakukan, yaitu menyilangkan tetua yang memiliki potensi produksi tinggi dan tahan penyakit. Penyakit gugur daun Colletothricum merupakan salah satu penyakit terpenting pada tanaman karet.Penyakit ini disebabkan oleh cendawan Colletothricumgloeosporioides.Gangguan penyakit ini dapat menurunkan produktivitas kebun, tertundanya saat okulasi di pembibitan,dan dalam serangan yang berat mengakibatkan bibit cacat, kerdil bahkan mati. Oleh karena telah dilakukan penelitian di Balai Penelitian Sungei Putih di kebun Entres untuk mengetahui ketahanan 22 klon IRR seri 400 dan klon pembanding PB 260.Parameter yang diamati adalah intensitas serangan dan periode laten, kemudian untuk melihat sifat ketahanan, dicari nilai heretabilitas (h2) dengan membandingakan ragam genetik dan ragam lingkungan terhadap parameter pengamatan. Terseleksi enam klon yang memiliki tingkat ketahanan yang tinggi terhadap intensitas serangan Colletotrichumyaitu IRR 428, IRR 429, IRR 446, IRR 451 dan IRR 452. Tidak adanya interaksi antara isolat dengan klon karena jenis isolat yang digunakan adalah Colletotrhicumgloeosporioides.Tingkat ketahanan dipengaruhi oleh klon yang dicerminkan dari nilai heretabilitas tinggi yaitu >0,5. Diterima : 10 Juli 2015; Direvisi : 8 September 2015; Disetujui : 25 September 2015 How to Cite : Pasaribu, S. A., Rosmayati., & Sumarmadji. (2015). Uji ketahanan klon karet IRR seri 400 terhadap beberapa isolat penyakit gugur daun Colletotrichum. Jurnal Penelitian Karet, 33(2), 131-142. Retrieved from http://ejournal.puslitkaret.co.id/index.php/jpk/article/view/178Â
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Isolation and characterization of three members of the multigenic family encoding ACC oxidase from H. brasiliensis during plant development : [Draft]
Get PDFApplying Ethephon, an ethylene releaser, to increase rubber production in H. brasiliensis has been practised for a long time. The effect of ethylene on latex production has been amply described, notably for lengthening latex flow and its regeneration. Nevertheless, little is known about the expression of genes involved in ethylene biosynthesis and response to ethylene. In this paper, we isolated and characterized genes encoding ACC oxidase, a key enzyme in ethylene biosynthesis in the plant. We then studied the effect of ethylene stimulation on the expression of ACO genes in various tissues during plant development. Three members of the ACO multigenic family were isolated from a bark cDNA library with RACE technology: HbACO-H4, HbACO-H5, and HbACO-O48. Full length cDNA sequences encoded for peptides of 318, 315, and 318 amino acids respectively for these 3 members, which had 79 to 92% protein identity and 75 to 86% nucleotide homology between them. Two genomic sequences were isolated: HbACO-H4, which was 1504 bp long and consisted of 2 introns and 3 exons, while Hb-ACO-H5 was 1456 bp long and consisted of 3 introns and 4 exons. These three genes were differentially expressed in different plant organs in response to ethylene stimulation
Microcutting of Hevea rubber genotype 78 and 91
No full textThe availability of clonai rootstocks of Hevea rubber is necessary to solve the problems encountered in seedling rootstocks such as high variation among plants, a lack of seeds and un certain seed season. Propagation of clonai rootstocks of rubber can be conducted by microcutting technique that is a technology based on in vitro culture. Explants used are axillary buds of young rubber seedlings at a two leaf umbrella stage. In order to propagate rubber rootstocks through microcutting technique in Indonesia, collaboration was formed between Indonesian Biotechnology Research Institute for Estate Crops (IBRIEC), Indonesian Rubber Research Institute (IRRI), and ClRAD France. In 2005 mass selection was conducted to select the best 100 genotypes from 43000 rubber seedlings derived from seeds of clone GTl, RRIM 600 and PB 260. The one hundred genotypes were then tested for their growth response to in vitro culture conditions and two ofthem i.e. genotype 78 and 91 showed the best response. Propagation ofgenotype 78 from 2007 to 2009 with 463 initial explants produced 6315 responsive explants (multiplication by 14-fold), where 2147 plantlets into acclimatization phase and 1322 explants were dead or no response. During the same period, genotype 91 with 273 initial explants produced 6703 responsive explants (multiplication by 25-fold) and 2084 plantlets into acclimatization phase. Dl/ring acclimatization, many plantlets of genotype 78, 91, and others were not survived due to unsuitable growing medium and environment conditions as weil as experimental treatments. The survival rate of plantlets was relatively low, 50 - 60 % on the best treatments. Hundreds of plants of gen 0 type 78 and 91 were produced du ring 2007 and 2009. As many as 13 plants of genotype 78 and 14 plants of genotype 91 as rootstocks were budded with ./ive difJerent recommended clones as scions and the budded success was 100%. It indicates that rootstocks derived from rubber microcutting are compatible with scions of recommended clones
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