1,720,955 research outputs found
DISTRIBUSI DAN FLUKTUASI POPULASI Spodoptera frugiperda ( Noctuidae : Lepidoptera ) PADA TANAMAN JAGUNG ( Zea mays ) DI KABUPATEN SIJUNJUNG
Full text linkKemampuan jelajah imago S. frugiperda yang tinggi diduga hama ini telah menyerang daerah lainnya di Sumatera Barat. Di Kabupaten Sijunjung sebelumnya tidak ada laporan serangan S. frugiperda, namun akhir tahun 2022 petani jagung mulai menemukan adanya serangan. Untuk itu telah dilakukan penelitian dengan tujuan mempelajari gejala serangan, tingkat serangan dan populasi serta distribusi S. frugiperda di Kabupaten Sijunjung. Penelitian ini dilaksanakan pada bulan Maret sampai Mei 2023 menggunakan metode survey dengan teknik pengambilan sampel purposive sampling. Lokasi pengambilan sampel pada 8 kecamatan yang ada di Kabupaten Sijunjung. Di tiap kecamatan kemudian ditentukan 2 lahan berukuran minimal 300 m2, selanjutnya pada lahan tersebut ditetukan 5 petak sampel berukuran 1 x 1 m2. Petak sampel pada setiap lahan diambil secara diagonal. Pengamatan dilakukan terhadap gejala, dan tingkat serangan serta penyebaran populasi. Hasil penelitian menunjukkan ditemukan gejala serangan S. frugiperda di seluruh sampel lokasi di Kabupaten Sijunjung. Gejala pada daun dan batang tanaman jagung, yaitu daun robek dan batang rusak atau patah. Persentase serangan berkisar antara 1,4 hingga 88,7 %. Populasi larva S. frugiperda yang ditemukan adalah rata rata 0,21 larva/tanaman. S. frugiperda menunjukkan keberadaannya pada seluruh kecamatan di Kabupaten Sijunjung. Pada satu musim tanam jagung hanya satu generasi yang terbentuk dengan puncak populasi larva pada umur tananam 21 HST dan puncak populasi imago pada umur 49 HST.
Keywords: distribusi, populasi, serangan, Spodoptera frugiperd
KEANEKARAGAMAN DAN KEPADATAN POPULASI NEMATODA PARASIT PADA RIZOSFIR TANAMAN KUBIS (Brassica oleraceae) DI SENTRA PRODUKSI SUMATERA BARAT
No full textPenelitian ini dilaksanakan dari bulan Juli sampai September 2012. Tujuan penelitian untuk mengetahui jenis dan kepadatan populasi nematoda parasit pada tanah perakaran kubis di Sumatera Barat. Metode penelitian menggunakan Purposive Random Sampling. Sampel diambil dari 3 Kabupaten yaitu: (1) Kabupaten Solok di Nagari Alahan Panjang, (2) Kabupaten Tanah Datar di Nagari Aie Angek, (3) Kabupaten Agam di Nagari Batagak. Hasil Penelitian menunjukkan bahwa nematoda parasit yang didapatkan pada tanah perakaran tanaman kubis di Sumatera Barat terdiri dari 7 Genus yaitu: Meloidogyne, Heterodera, Nacobbus, Tylenchorhynchus, Helicotylencus, Aphelencoides dan Longidorus. Keanekaragaman nematoda parasit pada tanah perakaran kubis di Kabupaten Tanah Datar lebih tinggi daripada Kabupaten Solok dan Kabupaten Agam, sedangkan kepadatan populasi tertinggi nematoda parasit pada tanah perakaran kubis terdapat di Kabupaten Agam. Nematoda yang memilki frekuensi kehadiran tertinggi 90% (absolut) di Kabupaten Agam yaitu Meloidogyne.
Kata Kunci: Keanekaragaman, Nematoda Parasit, Rizosfir, Brassica oleraceae
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Distribution and Attack Rate of Spodoptera frugiperda on Maize in Sijunjung District, West Sumatera Province
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The density and attack rates of Spodoptera frugiperda have been reported in various maize cultivation in Indonesia, but there has never been a report in Sijunjung District, West Sumatra. The research was conducted to study the attack level, density, and distribution of S. frugiperda in Sijunjung District. The study was carried out in March -May 2023 using a survey method in 8 sub-districts in Sijunjung District. The results showed that S. frugiperda had spread and attacked maize crops evenly in Sijunjung District, but the attack rate (26.96%) and density (0.24 individuals) were low. The highest attack was found in Nagari Guguak (88.7%). The high or low rate of attacks is influenced by differences in varieties, planting ages, and maize cultivation techniques. Meanwhile, the density is more influenced by age differences
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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