Judul: Genetic study of cacao (Theobroma cacao L.) resistance against black pod disease (Phytophthora palmivora Butl) in Indonesia.
Abstrak: Cacao (Theobroma cacao L.) is one of the estate crops having important role in economy Indonesia. Cacao cultivation faces a lot of constraints, such as crop pests and diseases which can reduce the quality and production of cacao. One of the main diseases which attack cacao in Indonesia is black pod disease caused by Phytophthora palmivora (Butl.) Butl. The disease caused yield losses ranging from 40 to 50% in Indonesia and worldwide.
Keyword: Black Pod, Mekanisme Ketahanan Struktural, Mekanisme Ketahanan Biokimia, Aktivitas kitinase, Aktivitas Peroksidase

Judul: Black Pod Rot Disease (Phytophthora palmivora Butl.) Control Management on Cocoa (Theobroma cacao L.) at Jatirono Plantation, PT Perkebunan Nusantara XII (Persero), Banyuwangi, East Java
Abstrak: Kegiatan magang bertujuan mempelajari budidaya tanaman kakao baik secara teknis maupun manajerial. Kegiatan magang juga bertujuan mempelajari manajemen pengendalian Phytophthora palmivora secara kultur teknis, manual, dan kimiawi. Magang dilaksanakan di Kebun Jatirono, PT Perkebunan Nusantara XII, Banyuwangi, Jawa Timur yang berlangsung dari bulan Januari 2020 hingga April 2020. Pengendalian P. pamivora secara kultur teknis dilakukan melalui pemangkasan dan pemupukan. Hasil analisis menunjukkan areal kakao yang memiliki kelembaban rendah memiliki tingkat serangan P. palmivora yang lebih rendah jika dibandingkan dengan areal dengan kelembaban tinggi. Pengendalian P. palmivora secara mekanis dilakukan dengan kegiatan membuang buah busuk (B3) yaitu menurunkan buah yang terserang P. palmivora. Jumlah buah yang diturunkan kemudian dikonversi menggunakan pod index di Afdeling Sumber Baru yaitu sebesar 33 yang menandakan setiap kehilangan 33 buah berarti telah terjadi kehilangan hasil sebanyak 1 kg. Pengendalian secara kimiawi dilakukan menggunakan fungisida berbahan aktif mankozeb dengan konsentrasi 0.83 g l-1 dan fosfonat dengan konsentrasi 20 ml l-1 ., tion. In addition, the aim of the internships was to study the management control of Phytophthora palmivora on cocoa in technically, manually, and chemically. The internships conducted at Jatirono Plantations, PT Perkebunan Nusantara XII (Persero), Banyuwangi, East Java, from January to April 2020. P. palmivora control in technical culture is pruning,and fertilizing. Analysis results shows that areas of cocoa that had low humidity had a low attack rate of P. palmivora when compared with areas that had high humidity. P. palmivora control manually is doing by dispose a rot pod. The amount of reduced pod then converted with pod index in Jatirono Plantations is 33 which means that every loss of 33 pod means that has been loss of 1 kilograms of cocoa beans. Chemical control is doing by fungicide that contains active material mancozeb with 0.83 g l- 1 consentrations and phosphonate with 20 ml l-1 consentrations
Keyword: cocoa, manually, cultural technic, chemical, Phytophthora palmivora

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: