Judul: The Effect of Turmeric Essential Oil in the Growth of Rhizoctonia sp. in Vitro
Abstrak: Rhizoctonia sp. merupakan salah satu cendawan patogen yang sering menyebabkan kerusakan tanaman di persemaian dimana penyebarannya sangat luas. Pengendalian hayati yang ramah lingkungan merupakan salah satu solusi untuk menekan penyebarannya. Minyak atsiri memiliki kandungan bahan aktif sebagai alternatif mengurangi ketergantungan kimia sintetik yang kurang ramah lingkungan. Penelitian ini bertujuan untuk menganalisis pengaruh minyak atsiri kunyit dalam menghambat pertumbuhan patogen Rhizoctonia sp. secara in vitro. Penelitian ini menggunakan metode pemberian minyak atsiri kunyit dengan beberapa konsentrasi yaitu 1%,5%,10% dan kontrol pada media PDA dan PDB. Pengamatan selanjutnya dilakukan secara makroskopis dan mikroskopis. Hasil penelitian menunjukkan bahwa nilai hambat tertinggi terdapat pada perlakuan kunyit 10%. Efektivitas pengendalian patogen Rhizoctonia sp. dipengaruhi oleh tingkat konsentrasi dan kandungan bahan aktif dalam minyak atsiri., Rhizoctonia sp. is one of the pathogenic fungi that often cause damage to plants in nurseries, where its spread is widespread. Environmentally friendly biological control is needed. Essential oils contain active ingredients as an alternative to reduce dependence on less environmentally friendly synthetic chemicals. This study aimed to analyze the effect of turmeric essential oil in the growth of Rhizoctonia sp. pathogen in vitro. The study applied turmeric essential oil at various concentrations, namely 1%, 5%, 10%, and a control, on PDA and PDB media, followed by macroscopic observations. The results showed that the highest controlling value was observed in the 10% turmeric concentration on both PDA and PDB media. The results of the study indicated that the highest inhibitory effect is observed in the 10% turmeric treatment. The effectiveness of controlling the Rhizoctonia sp. pathogen was influenced by the concentration level and active ingredients present in the essential oil.
Keyword: Essential Oil, in vitro, pathogen, Rhizoctonia sp., turmeric

Judul: Rhizoctonia sp. Inhibition Test using Citronella and Clove Essential Oils
Abstrak: Benih dan bibit di persemaian seringkali terserang oleh penyakit. Salah satu patogen penyebab penyakit yang sering ditemukan di persemaian adalah Rhizoctonia sp. Pengendalian hayati sangat diperlukan untuk menghambat pertumbuhan Rhizoctonia sp. Selain mengurangi kerusakan lingkungan akibat penggunaan fungisida kimiawi, bahan dasarnya sangat mudah didapatkan dengan harga yang terjangkau. Tumbuhan mengandung banyak bahan kimia yang merupakan metabolit sekunder dan digunakan oleh tumbuhan sebagai alat pertahanan dari serangan organisme pengganggu. Penelitian ini bertujuan untuk menganalisis pengaruh minyak atsiri serai wangi dan cengkih dalam menghambat pertumbuhan patogen Rhizoctonia sp. secara in vitro (media ADK dan KDK) dan in vivo (bibit sengon). Metode penelitian meliputi penyiapan isolat patogen, penghambatan secara in vitro dan in vivo, serta pengamatan mikroskopis. Minyak atsiri yang digunakan adalah serai wangi, cengkih, dan kombinasi serai wangi dengan cengkih. Konsentrasi yang digunakan adalah 0%, 0,1%, 0,5%, dan 1%. Minyak atsiri serai wangi dan cengkih mengandung senyawa antifungi dan antioksidan sehingga dapat mencegah dan menghambat patogen dalam menyebabkan penyakit. Serai wangi 1%, cengkih 0,5% dan cengkih 1% memberikan persentase penghambatan tertinggi terhadap pertumbuhan diameter isolat, luas serangan, dan intensitas serangan yang disebabkan oleh Rhizoctonia sp. Perlakuan minyak atsiri cengkih 1% memberikan penghambatan paling tinggi terhadap pertumbuhan biomassa patogen. Perbedaan jenis minyak atsiri berpengaruh nyata terhadap parameter diameter isolat, luas dan intensitas serangan penyakit. Perbedaan konsentrasi minyak atsiri memberikan pengaruh yang nyata terhadap parameter diameter isolat, biomassa, luas dan intensitas serangan penyakit. Minyak atsiri serai wangi 1%, cengkih 0,5 % dan cengkih 1% menghasilkan penghambatan tertinggi untuk seluruh parameter yang diukur., Diseases often attack seeds and seedlings in nurseries. One of the disease-causing pathogens often found in nurseries is Rhizoctonia sp. Biological kontrol is needed to inhibit the growth of Rhizoctonia sp. In addition to reducing environmental damage due to the use of chemical fungicides, the essential ingredients are straightforward to obtain at an affordable price. Plants contain many chemicals which are secondary metabolites and are used by plants as a means of defense from attacks by disturbing organisms. This study aims to analyze the effect of citronella and clove essential oils on inhibiting the growth of the pathogen Rhizoctonia sp. in vitro (on medium PDA and PDB) and in vivo (sengon seedlings). Research methods include preparing pathogen isolates, in vitro and in vivo inhibition, and microscopic observations. The essential oils used are citronella, cloves, and a combination of citronella and cloves. The concentrations used were 0%, 0,1%, 0,5%, and 1%. Essential oils of citronella and cloves contain antifungal and antioxidant compounds that can prevent and inhibit fungi from causing disease. Citronella 1%, cloves 0,5%, and cloves 1% gave the highest percentage of inhibition on the growth of isolate diameter, disease incidence, and disease severity caused by Rhizoctonia sp. Treatment of 1% clove essential oil gave the highest inhibition of the growth of fungal biomass. The different types of essential oils significantly affect the parameters of the isolate diameter, disease incidence, and disease severity. Differences in essential oil concentrations significantly affected the parameters of isolate diameter, biomass, disease incidence, and disease severity. Essential oils of 1% citronella, 0.5% cloves, and 1% cloves produced the highest
Keyword: antifungal, concentration, in vitro, in vivo, pathogen

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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