Judul: Deteksi penyebab penyakit kerdil pada tanaman lada (piper nigrum L.)
Abstrak: Penyakit kerdil pada tanaman lada merupakan penyakit penting ketiga saat ini sesudah penyakit busuk pangkal batang dan penytakit kuning. Penyakit ini telah luas di daerah-daerah penanaman lada di Indonesia. ...
Keyword: Plant viruses, tanaman lada

Judul: Deteksi dan identifikasi penyebab penyakit belang pada tanaman lada (Piper nigrum L)
Abstrak: Penyakit belang pada tanaman lada pada awalnya diduga disebabkan oleh mikoplasma, namun hasil penelitian di beberapa negara menunjukka n bahwa penyakit ini disebabkan oleh dua jenis virus yaitu Cucumber Mosaic Virus (CMV) dan Piper Yellow Mottle Virus (PYMV). Tujuan penelitian ini adalah untuk mendeteksi dan mengidentifikasi virus penyebab penyakit belang pada tanaman lada yang terdapa t di pulau Bangka, Lampung, Sukabumi, dan Bogor, serta untuk mengetahui efisiensi tiga jenis serangga vektor dalam penularan virus CMV dan PYMV. Hasil pengamatan yang dilakukan di sembilan kebun petani dibeberapa desa di Pulau Bangka menunjukkan serangan sebesar 95% dengan gejala umum belang dan keriting. Gejala serangan yang sama ditemukan pula di beberapa kebun petani di Lampung dan Bogor, sedangkan pada lokasi di Kebun Percobaan Balai Penelitian Tanaman Rempah dan Obat Sukamulya didominasi gejala be lang. Deteksi daun sakit bergejala keriting dan belang dengan uji ELISA menunjukkan sampel positif bereaksi dengan antiserum CMV dan Banana Streak Virus (BSV). Penularan virus dengan perlakuan jumlah serangga vektor, kontrol, 1, 3, 7, dan 10 ekor menunjukkan bahwa kutu daun Aphis gossypii tidak dapat menularkan kedua jenis virus tersebut. Penularan menggunakan serangga vektor Planococcus minor dan Ferrisia virgata pada perlakuan satu ekor serangga vektor diperoleh hasil bahwa hanya PYMV yang dapat ditula rkan dengan efisiensi 40-100%. Amplifikasi genom virus dengan PCR menggunakan 5’-Badna T dan 3’-SCBVR1 diperoleh amplikon berukuran ± 650 bp. Perunutan nukleutida amplikon hasil PCR menunjukkan adanya homologi sekuen sebesar 85% dengan sekuen PYMV ORF1 yang dilaporkan oleh de Silva et al.
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Judul: Enhancement of photon absorbtion on BaxSr1-xTiO3 thin films semiconductor using photonic crystals.
Abstrak: In this research, has been conducted BaxSr1-xTiO3 (BST) thin films manufacturing for mole fraction x = 0.25, 0.35, 0.45, and 0.55; and concentration of 1 molar using chemical solution depositon (CSD) method. The materials, which are used in this research, are barium acetate [Ba(CH3COO)2, 99%], strontium acetate [Sr(CH3COO)2, 99%], titanium isopropoxide [Ti(C12O4H28), 97.999%], gallium trioxide [Ga2O3], 2-methoxyethanol [H3COOCH2CH2OH, 99%] and 1 x 1 cm of transparent conductive oxide (TCO) glass as substrate. Two BST thin films are made that for BST thin films which are doped by 10% galium (BGST) as p-type layer and pure BST solution as n-type. BST solution is made by reacting barium acetate [Ba(CH3COO)2, 99%], strontium acetate [Sr(CH3COO)2, 99%] and titanium isopropoxide [Ti(C12O4H28)] into 2-methoxyethanol solvent [H3COOCH2CH2OH, 99%] in accordance with mass gram for each x value. While, BGST solution is made in the same way as BST solution, plus adding gallium at 10% of the mass of BST. Once all materials are reacted, then vibrated using ultrasonic for 90 minutes, and followed by coating BGST / BST on the TCO substrate. Once the layer is formed, then annealed for 15 hours at temperature of 500 °C with increasing rate of 1.67 oC/minute. Characterizations of BST thin films with or without photonic crystals include the absorbance and transmittance in the visible light spectrum, as well as the electrical photoconductivity characterizations. From BST thin films without photonic crystals indicate that our thin films have light absorption area on almost the entire range of the visible light spectrum even to the infrared range with absorption value over than 67.6%, in addition, it can be seen that the maximum absorbance of BST thin films for all mole fractions lie in blue to green light spectrum region, 457 nm ≤ λ ≤ 570 nm and the minimum in yellow to red light spectrum region, 570 nm ≤ λ ≤ 678 nm. The largest absorbance is found at x = 0.25 with average absorbance value of 92.04% and maximum and minimum absorbance peaks at wavelength of 500.89 and 657.72 nm, respectively. At x = 0.35, average absorbance value decreased to 83.55% with maximum and minimum peaks at 505.73 and 613.68 nm, respectively. Then increased to 91.16% at x = 0.45 with maximum and minimum peaks at 506.04 and 618.56 nm, respectively. At x = 0.55, average absorbance value decreased to 80.12% with maximum and minimum peaks at 507.85 and 608.79 nm, respectively. Moreover, it can be seen that the addition of barium mole fraction leads to wider maximum absorbance or minimum transmittance peaks and narrower minimum absorbance or maximum transmittance peaks in the same range of the green and blue & red light spectrums, respectively. BST thin films with photonic crystals show increasing in absorption for all x values in the range of 3.04 into 13.33%. At x = 0.25, average absorbance percentage increased 3.96% from 92.4 into 95.68%, for x = 0.35 average percentage increased 7.07% into 89.45 from 83.55%. Furthermore, average absorbance of BST thin films at x = 0.45 increased 3.04% from 91.16 into 93.93% and x = 0.55 has
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