Judul: Vegetative Propagation of Cloves (Syzygium aromaticum) by Marcotting Method on Agroforestry Land in Ngambarsari Village, Wonogiri
Abstrak: Cengkih merupakan tanaman yang menghasilkan bunga dengan harga yang tinggi di pasar ekonomi dan banyak dibudidayakan di Indonesia, khususnya di Desa Ngambarsari, Wonogiri. Perbanyakan vegetatif cengkih dinilai lebih efektif dan unggul. Keunggulan utama dari perbanyakan vegetatif yaitu sifat bibit yang serupa dengan induknya. Salah satu perbanyakan vegetatif yang sering digunakan karena tingkat keberhasilannya tinggi pada tanaman berkayu adalah cangkok. Penelitian cangkok cengkih ini dilakukan selama 6 bulan (Desember 2021- Juni 2021) di lahan agroforestri Desa Ngambarsari, Wonogiri. Percobaan menggunakan Rancangan Acak Lengkap faktorial, dengan kombinasi perlakuan yang digunakan adalah jenis ZPT (Zat Pengatur Tumbuh) dan lama sayatan. Hasil percobaan menghasilkan cangkok cengkih berakar dengan rentang 0%-60%. Hasil sidik ragam menunjukan bahwa interaksi jenis ZPT dan lama sayatan tidak berpengaruh nyata terhadap persentase berakar, jumlah akar, dan panjang akar cangkok cengkih., Cloves are plants that produce fruit at high prices in the economic market and are widely cultivated in Indonesia, especially in Ngambarsari Village, Wonogiri. Vegetative propagation of cloves is considered more effective and superior .The main advantage of vegetative propagation is the similar nature of the seedlings to the parent. One of the vegetative propagations that is often used because of its high success rate in woody plants is marcotting. This clove marcotting research was carried out for 6 months (December 2021- June 2021) on agroforestry land in Ngambarsari Village, Wonogiri. The experiment used a factorial Complete Randomized Design, with the combination of treatments used being the type of ZPT (Growth Regulator) and the duration of the incision left. The results of the experiment produced rooted clove grafts in the range of 0%-60%. The results of the fingerprints showed that the interaction of ZPT type and incision duration was left with no noticeable effect on the percentage of roots, the number of roots, and the length of the clove graft roots.
Keyword: clove, incision left, marcotting, PGR, root

Judul: Observation of dieback disease of  clove in Semarang and Tegal  regencies, Central Java
Abstrak: Cengkih (Syzygium aromaticum L. Merr. & Perry) merupakan tanaman rempah asli Indonesia yang memegang peranan penting dalam pembangunan perkebunan untuk peningkatan devisa negara. Di Indonesia, bunga cengkih kering digunakan terutama untuk bahan baku campuran rokok kretek dan sebagian kecil untuk keperluan industri makanan, minuman, kosmetik dan farmasi. Serangan hama dan penyakit menyebabkan terhambatnya pertumbuhan tanaman cengkih bahkan kematian pada tanaman. Hal ini dapat menurunkan kualitas dan kuantitas produktivitas cengkih. Salah satu penyakit yang menyerang tanaman cengkih dan paling merusak tanaman cengkih yaitu penyakit mati pucuk yang disebabkan oleh Bakteri Pembuluh Kayu Cengkih (BPKC). Penelitian ini dilakukan untuk mengamati kondisi serangan penyakit mati pucuk di lapangan dan mengetahui pengaruh praktek-praktek budidaya serta kemungkinan penyebab penyakit mati pucuk. Pengamatan dilakukan di dua kabupaten yaitu Kabupaten Semarang dan Tegal, Provinsi Jawa Tengah. Pengamatan dilakukan pada pertanaman cengkih yang berada di daerah perbukitan dan daerah sekitar pemukiman, kemudian dihitung kejadian dan keparahan gejala penyakit mati pucuk, serta mengamati keberadaan penggerek dan kanker batang. Sampel gejala penyakit mati pucuk diambil dan diamati di laboratorium untuk melihat keberadaan bakterinya. Kejadian serangan penyakit mati pucuk di Kabupaten Tegal lebih tinggi dibandingkan Kabupaten Semarang sedangkan keparahan serangan penyakit mati pucuk di Kabupaten Semarang lebih tinggi dibanding Kabupaten Tegal. Penyakit BPKC tidak hanya disebabkan oleh bakteri saja tetapi ada peran OPT lain yaitu penggerek dan kanker batang, Cloves (Syzygium aromaticum L. Merr. & Perry) is an Indonesia origin spices, has important role in the development of plantations to increase state revenues. In Indonesia, dried cloves used primarily as raw material mixture of cigarettes and a small portion for the purposes of the food industry, cosmetic and pharmaceutical. Pests and diseases causes inhibition of cloves growth and death. It can decrease the quality and quantity of cloves productivity. One of the diseases which can infect cloves is called dieback caused by Wooden Vessels Bacteria Cloves (in indonesian is BPKC). The purpose of this study were to observe the dieback disease condition in the field, and determine the influence of cultivation practices on the diseases. Observations were ca rried out in districts of Semarang and districts of Tegal in Central Java Province. Observations were made on the plantation in hilly areas and residential areas, and then were be calculated the incidence and severity of dieback symptoms. The existence of stem canker and stem borer symptoms were also observed which might be accompanied to dieback disease. Symptoms of dieback samples were detection of bacteria in the laboratory. Dieback incidence in district of Tegal is higher than the district of Semarang while dieback severity in district of Semarang is higher than the district of Tegal. Bosed on field observation and laboratory detection, the dieback symptoms on clove in those areas were not only caused by bacteria, but stem canker and stem borer were also have a role on the development of the symptoms
Keyword: cengkih, kanker, penyakit mati pucuk, serangga

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
Keyword: