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Notes on the Citrus Rust Mite, Phyllocoptruta oleivora (Ashmead), as a Major Pest of Citrus in Indonesia
No full textMost citrus farmers in Indonesia believed that rust on citrus fruits resulted from insect attacks. This research aims to determine the cause of rust on citrus fruit and its damage intensity. The study was carried out in commercial citrus plantations in three provinces, on Citrus sinensis and C. reticulata plantations in East Java, C. reticulata and C. suhuensis in West Kalimantan and C. suhuensis in North Sumatra. An additional observation was also conducted to collect mite specimens on citrus plantations in Malang, East Java. Scanning Electron Microscope (SEM) and light microscope were used to observe and identify each collected sample. Results showed that the cause of rust-colored citrus fruit in three provinces is the citrus rust mite, Phyllocoptruta oleivora (Ashmead). It belongs to the family Eriophyidae with two pairs of legs with regular segmentation, five-rayed featherclaws, and a net pattern on prodorsum. The specific damage produced by this mite is rust-colored symptoms. Damage intensity of citrus rust mite in tree provinces averaging 32.6%, ranging from 30 to 40%, and ca. the mite attacks 90% of citrus fruits. Predaceous mites, predaceous insects, and entomo-acaropathogenic fungi are found on plantations
Pengaruh Perbedaan Tahun Pangkas Tanaman Teh terhadap Kelimpahan Populasi Wereng Pucuk Teh Empoasca sp. pada Kebun Teh Afdeling Wonosari PTPN XII
No full textTanaman teh Camellia sinensis merupakan komoditas perkebunan yang banyak dikembangkan di Indonesia. Budidaya tanaman teh tidak lepas dari permasalahan yang disebabkan oleh hama dan penyakit tanaman. Salah satu hama utama yang menyerang tanaman teh adalah Wereng Pucuk Teh (WPT). Serangan dan penyebaran WPT sangat cepat, serangan hama ini dapat menurunkan produksi 50-80% karena pertumbuhan pucuk terganggu. WPT menyerang pucuk dan daun muda tanaman teh. Pemangkasan tanaman teh dapat mempengaruhi jumlah pucuk daun yang dihasilkan sehingga perbedaan tahun pangkas (TP) akan mempengaruhi kelimpahan populasi dan intensitas serangan WPT pada tanaman teh. Tujuan penelitian ini adalah untuk mengetahui kelimpahan populasi dan tingkat serangan WPT pada tanaman teh TP I dan tanaman teh TP III.
Penelitian dilaksanakan pada bulan Januari sampai Maret 2023 di PT Perkebunan Nusantara XII Kebun Wonosari yang terletak di Bodean Putuk, Toyomarto, Kecamatan Singosari, Kabupaten Malang, Jawa Timur. Penelitian ini dilaksanakan pada Afdeling Wonosari untuk pengamatan kelimpahan populasi dan intensitas serangan hama WPT. Terdapat tiga TP pada lokasi penelitian, yaitu TP I, II dan III. Pada penelitian ini, lahan yang digunakan adalah lahan TP I dan TP III. Pada masing-masing TP ditetapkan sepuluh nomor lahan sehingga total nomor lahan yang digunakan yaitu 20 nomor lahan. Pada masing-masing nomor lahan ditetapkan dua petak pengamatan berukuran 10 x 20 m secara acak sehingga total keseluruhan petak pengamatan yang ditetapkan adalah 40 petak. Jumlah tanaman teh contoh yang diamati untuk satu petak pengamatan adalah 16 tanaman sehingga total tanaman teh contoh yang akan diamati pada penelitian ini yaitu 640 tanaman. Penetapan tanaman contoh menggunakan cara pengambilan sampel diagonal sistematis. Pada setiap tanaman teh contoh diamati empat daun mengikuti arah mata angin yaitu arah Timur, Utara, Barat, dan Selatan. Total daun teh contoh yang diamati dalam satu petak lahan yaitu 64 daun sehingga total keseluruhan daun teh yang akan diamati pada penelitian ini yaitu 2560 daun teh contoh. Pengamatan daun teh contoh dilakukan untuk mengetahui intensitas serangan WPT pada tanaman teh tersebut. Pengamatan intensitas serangan WPT dilakukan dengan mengamati setiap daun teh contoh yang telah ditetapkan kemudian dilakukan penentuan nilai tingkat kerusakan daun dengan skoring. Setelah itu, dilakukan perhitungan intensitas kerusakan daun dengan menggunakan rumus intensitas serangan. Pengamatan dan perhitungan populasi WPT dilakukan pada nomor dan petak lahan yang sama dengan penentuan dan perhitungan intensitas serangan WPT diatas. Pengamatan dilakukan menggunakan perangkap lekat kuning berukuran 25 x 19 cm yang dilekatkan pada seluruh bagian botol plastik air mineral berukuran 1,5 L. Perangkap yang digunakan berjumlah 5 buah pada setiap petak pengamatan. Perangkap lekat kuning yang
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telah ditempel pada botol plastik kemudian diikatkan pada kayu penyangga dengan panjang lebih kurang 1 m. Ketinggian rata-rata tanaman teh lokasi penelitian yaitu lebih kurang 1 meter. Perangkap lekat kuning diletakan pada bagian tengah petak lahan dan pada bagian tengah masing-masing sisi petak lahan dengan menggunakan tongkat kayu yang ditancapkan di tanah hingga jarak ketinggian botol plastik dengan bidang petik tanaman teh lebih kurang satu jengkal. Kemudian WPT yang ditemukan pada perangkap lekat kuning dicatat jumlah populasinya. Pengamatan dilakukan setiap seminggu sekali selama delapan minggu pengamatan di masing-masing lahan TP I dan TP III. Pada setiap minggu pengamatan, perangkap lekat kuning tersebut diganti dengan yang baru dan dilakukan pemasangan kembali seperti yang telah dilakukan sebelumnya. Selain pengamatan dan perhitungan intensitas, dilakukan pula pengukuran ketinggian lokasi penelitian, lebar bidang petik, suhu dan kelembapan serta curah hujan. Data kelimpahan dan intensitas serangan yang didapatkan kemudian diuji menggunakan uji t dengan taraf kesalahan 5% untuk mengetahui pengaruh perbedaan TP terhadap kelimpahan populasi dan intensitas serangan hama serta melakukan uji korelasi untuk mengetahui hubungan antara kelimpahan populasi dan intensitas serangan dengan ketinggian lokasi penelitian, lebar bidang petik, suhu, kelembapan dan curah hujan.
Hasil penelitian menunjukkan WPT ditemukan lebih sedikit pada TP I dibanding TP III. Hal ini dapat dilihat dari rata-rata kelimpahan populasi WPT pada TP I lebih rendah dibanding TP III yaitu 12,6 dan 19,0. Didukung dengan data pengamatan lebar bidang petik TP I yang lebih kecil dibanding TP III yaitu 69,57 cm dan 177,76 cm. Intensitas serangan WPT pada TP I lebih rendah dibanding TP III. Suhu saat pengamatan berkisar antara 23-27oC. Pada suhu 23oC, WPT yang hadir lebih banyak dibanding pada suhu 27oC. Kelembapan saat pengamatan berkisar antara 73-84%. WPT hadir lebih banyak pada kelembapan 84% dibanding pada kelembapan 73%. Dari data tersebut, perbedaan kelimpahan populasi dipengaruhi oleh suhu, kelembapan, dan lebar bidang petik sedangkan intensitas serangan WPT pada tanaman teh dipengaruhi oleh suhu dan kelembapan. Suhu berkorelasi negatif sedangkan lebar bidang petik berkorelasi positif terhadap kelimpahan populasi dan intensitas serangan. Ketinggian tempat dan curah hujan tidak mempengaruhi kelimpahan dan intensitas serangan WPT
Effects of Compost on Nematode Pratylenchus sp. (Tylenchida: Pratylenchidae) Population in Patchouli
No full textPatchouli is seen as one of the most important export commodities in Indonesia. The presence of parasitic nematode Pratylenchus sp. creates a barrier to plant cultivation. Increasing organic content in soil by applying compost in the plantation is one of approaches in controlling the nematode. This research was mainly aimed to study the effects of compost fertilization on the population growth of nematode Pratylenchus sp. and yields on patchouli. These research used a Completely Randomised Design (CRD) consisting of 12 treatments with three replicates. Selected plant was inoculated with nematodes with the following initial population: 100, 200, 300, 400, and 500 nematodes in soil with and without compost. The plant with no inoculation was used as control. The result of the research confirmed that the addition of compost was capable of suppressing the population of nematode Pratylenchus sp. as much as 58.93 - 67.31% and 40.74 - 59.19% in root and in soil of each treatment, respectively. Compost applied in each treatment positively affected the increasing amount of Patchouli oil yielded, and it could also reduce the loss as much as 18.34 - 43.36%. Trichoderma sp. was found to be dominant in compost in the treatment with its population of 2.1 × 104 propogul/g
COMPARISON OF FIVE LEGUMES AS HOST OF Tetranychus sp. (ACARI: TETRANYCHIDAE) MASS REARING
No full textTwo spotted mite (TSM) Tetranychus sp. is often used as host for predator mite Phytoseiidae mass rearing. To obtain high population of TSM in short time, it must be reared in host plants that support optimum growth and development. The objective of this research was to observe population development of TSM on legumes such as mungbean (Vigna angularis), adzukibean (V. radiata), snapbean (Phaseolus vulgaris) and soybean (Glycine max) (Wilis and Anjasmoro cultivars) and to compare the growth of the legumes based on their fresh leaf weight and leaf area, and cost seed index (CSI). The results showed that mungbean was suitable host plant for TSM mass rearing because its population on this legume was the highest. Mungbean’s fresh leaf weight and leaf area was the highest. If TSM is reared in plant in greenhouse, CSI will become one of criteria for determining the host plant. Although CSI of mungbean was low because TSM population that was reared on it is the highest, the mungbean was the most suitable host plant for TSM growth and development. Another host plant that was suitable for TSM reared was adzukibean
Occurrence of Cassava Lace Bug Vatiga illudens (Drake, 1922) (Hemiptera: Heteroptera: Tingidae) in Bali, Indonesia
Full text linkCassava Lace Bugs (CLB) are native pest of cassava (Manihot esculenta Crantz, Euphorbiaceae) to the Neotropical Region, mainly in Brazil. On the other hand, East Java was the first region in Indonesia to record the presence of CLB in 2021, however, it has not been reported in other regions in Indonesia. Therefore, the very importance to recognise the occurrence of CLB in other regions in Indonesia. Based on this, the research has been carried out starting with a field survey, observing behaviour of insect in the field and identify morphologically in the laboratory. The survey results show that the infestation of CLB has been found in lowland, medium, and highland areas in Bali. Symptoms of infestation on the upper leaf surface are small yellow spots with brownish variations. Based on the identification key, CLB from Bali Indonesia, shows a characteristic of a head with a pair of frontal spines. Based on this evidence, the CLB insect can be identified as Vatiga illudens (Hemiptera: Heteroptera: Tingidae). It is the first report of novel distribution areas for V. illudens in Bali, Indonesia. The results of this research are important because V. illudens is one of the main pests of cassava.
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
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
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