Judul: Penggunaan Bakteri Kitinolitik untuk Mengendalikan Penyakit Akar Putih pada Bibit Karet (Hevea brasiliensis).
Abstrak: Karet merupakan salah satu tanaman industri yang memiliki peran penting sebagai komoditas ekspor. Salah satu jenis penyakit yang paling merugikan pada perkebunan karet yaitu penyakit jamur akar putih (JAP). Pengendalian hayati menggunakan bakteri kitinolitik merupakan salah satu alternatif dalam pengendalian tanaman. Penelitian ini bertujuan untuk mengetahui kemampuan beberapa isolat bakteri kitinolitik untuk mengendalikan penyakit akar putih pada bibit karet. Penelitian dilakukan pada bulan Mei sampai Desember 2017. Pengujian dilakukan dalam dua tahap yakni in vitro dan in planta. Bakteri kitinolitik yang diuji adalah E.TB7, R.T.B2, E.T.C4, E.T.B5, NAP05, NAP21, dan fungisida Anvil 50 EC sebagai pembanding. Pengujian secara in vitro dilakukan dengan metode dual culture. Variabel yang diamati adalah zona hambatan dan abnormalitas hifa. Pengujian secara in planta dilakukan dengan menggunakan bibit tanaman karet yang diinokulasi oleh Rigidoporus lignosus. Bakteri kitinolitik dengan kepadatan 108 cfu/ml diaplikasikan dengan cara menyiram 100 ml/tanaman secara merata. Tingkat keparahan penyakit diukur 60 hari setelah inokulasi. Bakteri kitinolitik E.T.C4 dan E.T.B7 mampu menekan keparahan penyakit akar putih.
Keyword: dual culture, in planta, Rigidoporus lignosus, pengendalian hayati

Judul: Eksplorasi Bakteri Lisis sebagai Agens Pengendalian Hayati Penyakit Akar Putih (Rigidoporus lignosus (Kloztch) Imazeki) pada Tanaman Karet.
Abstrak: The hevea rubber (Hevea brasiliensis) is one of the important commodity in Indonesia for export purposes. One of the obstacles to be limiting in the production of hevea rubber is white root fungus disease caused by Rigidoporus lignosus. The purpose of this study was to explore and select a lysis bacteria from hevea rubber rhizosphere which have the potential as biological control agent of the disease. This research had been conducted in laboratory Wish, Dramaga, Bogor and laboratory Mycology, Departement of plant protection, faculty of agriculture, IPB on December 2014 until March 2015. Of the 251 isolates obtained in this study, 118 isolates on has the ability as cellulolytic, 68 isolates are cellulolytic and chitinolytic, and 65 isolates did have both of these properties. Out of the isolates that have lysis properties, 147 (79%) were not pathogenic based on the hypersensitivity test in tobacco plants. Among of those non-pathogenic isolates, 30 isolates could inhibit the radial growth R. lignosus in vitro testing. Based one the score of lysis index, inhibition zone, and growth inhibition, 13 isolates might be potential as biological control agents of R. lignosus.
Keyword: antagonis, kitinolitik, selulolitik, Rigidoporus lignosus

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
Keyword: