Judul: The Effect of Shading Time for Growth and Yield of  Chili Pepper (Capsicum frutescens L.)
Abstrak: Cabai rawit (Capsicum frutescens L.) merupakan salah satu tanaman hortikultura di Indonesia yang memiliki nilai ekonomi tinggi dan tingkat kebutuhan yang tinggi. Permasalahan utama dalam produksi tanaman cabai rawit adalah harga penjualan cabai rawit yang berfluktuasi. Fluktuasi harga cabai rawit ini seringkali tidak menguntungkan petani karena pada saat produksi melimpah harga cabai rawit turun, tetapi pada produksi yang sedikit harga cabai rawit naik. Penelitian ini bertujuan mengetahui pengaruh waktu pemberian naungan terhadap pertumbuhan dan hasil tanaman cabai rawit pada lokasi yang berbeda. Penelitian dilakukan di Kebun Percobaan Leuwikopo, IPB pada Agustus 2022 hingga Maret 2023. Rancangan percobaan menggunakan Nested (tersarang) Rancangan Kelompok Lengkap Teracak (RKLT) 2 faktor. Faktor pertama yaitu lokasi yang terdiri dari lahan A (samping Green House) dan lahan B (lahan antara kelas). Faktor kedua yaitu naungan yang terdiri dari 3 taraf, yaitu tanpa naungan, naungan 50%, dan naungan 90%. Percobaan menggunakan 3 ulangan, sehingga terdapat 18 satuan percobaan. Setiap ulangan terdiri dari 54 tanaman, sehingga jumlah tanaman yang ditanam sebanyak 972 tanaman dengan 10 tanaman contoh pada setiap ulangan. Hasil penelitian menunjukkan perlakuan intensitas naungan mempengaruhi penundaan panen tanaman cabai rawit. Pemberian naungan mampu menunda panen cabai rawit di lahan lebih lambat hingga 12 hari. Intensitas naungan 50% dan lokasi N2 memberikan hasil yang terbaik pada parameter yang diuji. Hasil panen dan kandungan capcaisin tanaman cabai rawit tertinggi didapatkan pada tanaman kontrol atau tidak ternaungi. Jarak tanam perlu diperhatikan agar lebar kanopi antar tanaman tidak tumpang tindih., Chili pepper (Capsicum frutescens L.) is one of the horticultural crops in Indonesia that has high economic value and high demand. The main problems in the production of chili pepper is fluctuating selling price. These fluctuations often unprofitable for farmers because when production is abundant will be falling price, but when production is low there will be rises price of chili pepper at different locations. This study aimed to determine the effect of shading time for the growth and yield of chili pepper. The experiment was conducted in Leuwikopo Experimental Farm, IPB from August 2022 to Maret 2023. The experimental design used a 2-factor Nested Complete Randomized Group Design (RKLT). The first factor was location which consisted of land A (next to Green House) and land B (between classes). The second factor was shading which consisted of 3 levels, namely no shade, 50% shade, and 90%. The experiment was carried out in 3 replications, so there were 18 experimental units. Each replicates consisted of 54 plants, so the number of plants was 972 plants with 10 sample plants in each replicates. The results showed that shading intensity was affected the harvest delay of chili pepper. Shade treatment was able to delay the harvest of chili pepper in the field up to 12 days slower. Shading intensity of 50% and location of N2 gave the best results for the parameters tested. The highest yields and capsaicin content of chili pepper were obtained from unshaded plants. Spacing needs to be considered so the width of the canopy between plants does not overlap.
Keyword: growing environtment, price, harvest age, growth, productivity

Judul: The Effect of Giving Intensity of Shade at Several Stages on Yield of Cayenne Pepper (Capcisum frutescens L.)
Abstrak: Permasalahan dalam budidaya cabai pada saat panen raya adalah produksi cabai yang melimpah sementara harga yang rendah. Pemberian naungan adalah salah satu cara untuk menunda waktu panen dengan memanipulasi lingkungan tumbuh. Penelitian ini bertujuan mengetahui pengaruh naungan dan waktu pengaplikasiannya serta interaksi keduanya yang optimal untuk hasil dan penundaan waktu panen tanaman cabai rawit. Rancangan percobaan yang digunakan adalah split plot dengan rancangan lingkungan Rancangan Kelompok Lengkap Teracak (RKLT) 2 Faktor. Faktor pertama terdiri dari tujuh taraf naungan, yaitu tanpa naungan, naungan 25%, 30%, 50%, 60%, 90%, dan 100%. Faktor kedua terdiri dari empat waktu pengaplikasian naungan, yaitu pada saat tanaman berbunga, terbentuk bakal buah, buah hijau, buah merah. Percobaan dilakukan sebanyak 3 ulangan, sehingga terdapat 84 satuan percobaan. Setiap satuan percobaan terdiri dari 20 tanaman. Hasil penelitian menunjukkan bahwa perlakuan terbaik untuk hasil tanaman cabai rawit ditunjukkan oleh perlakuan naungan 25% dan waktu aplikasi pada saat buah merah. Perlakuan naungan 60% dengan waktu pengaplikasian pada saat tanaman berbunga memberikan umur panen tertinggi., The problem in chili cultivation at the time of harvest is the abundance of chili production while the price is low. Shading is one way to delay harvest time by manipulating the growing environment. This study aims to determine the effect of shade and time of application as well as the optimal interaction between the two for yield and delay in harvesting cayenne pepper. The experimental design used was a split plot with a 2-factor Complete Randomized Group Design (RKLT) environmental design. The first factor consists of seven levels of shade, namely no shade, 25% shade, 30%, 50%, 60%, 90%, and 100%. The second factor consisted of four times when the shade was applied, namely when the plants were flowering, ovule was formed, green fruit, and red fruit. The experiment was carried out in 3 replications, so there were 84 experimental units. Each experimental unit consisted of 20 plants. The results showed that the best treatment for the yield of cayenne pepper was indicated by a 25% shade treatment and application time when the fruit was red. The 60% shade treatment with application time at the time of flowering plants gave the highest harvest age.
Keyword: growing environment, growth, harvest, harvest age, productivity

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.
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