Judul: Effect of Mulch Application on Temperature and Groundwater Fluctuations and Red Chili Plant Growth (Capsicum annum L.) on Latosol Dramaga
Abstrak: Cabai merah merupakan bahan pangan penting. Namun upaya pemenuhan bahan pangan ini dihadapkan berbagai tantangan, salah satunya adalah lahan yang terbatas. Pemanfaatan lahan yang terbatas secara optimal sehingga dapat menghasilkan produktivitas yang tinggi antara lain dengan menerapkan teknik budidaya yang sesuai salah satunya yaitu dengan pengaplikasian mulsa plastik. Penelitian dilakukan di daerah dengan curah hujan tahunan yang tinggi seperti di Dramaga, Bogor. Penelitian ini bertujuan mengetahui pengaruh mulsa plastik terhadap karakteristik tanah khususnya terhadap fluktuasi suhu dan kadar air tanah harian serta lebih lanjut pengaruhnya terhadap pertumbuhan dan produktivitas tanaman cabai merah pada Latosol Dramaga. Penelitian ini menggunakan rancangan acak kelompok (RAK) faktor tunggal dengan perlakuan tanpa mulsa (M0) dan mulsa plastik (M1). Data yang diperoleh dianalisis ragam pada tingkat kepercayaan 95% atau taraf nyata 5%. Hasil penelitian menunjukkan suhu dan kadar air tanah harian cenderung lebih tinggi pada perlakuan mulsa plastik. Perlakuan mulsa plastik berpengaruh nyata terhadap suhu dan kadar air tanah. Perbedaan nyata terdapat pada tinggi tanaman pada umur 8 MST dan jumlah daun pada umur 2 MST dan 8 MST. Perlakuan mulsa plastik berpengaruh nyata terhadap bobot buah., Red chili is an important food ingredient. However, efforts to fulfill this food supply are faced with various challenges, one of which is limited land. Utilization of limited land optimally so that it can produce high productivity, among others, by applying appropriate cultivation techniques, one of which is the application of plastic mulch. The study was conducted in areas with high annual rainfall such as in Dramaga, Bogor. This study aims to determine the effect of plastic mulch on soil characteristics, especially on dailiy fluctuations in temperature and daily groundwater content and further effect on the growth and productivity of red chili plants in Latosol Dramaga. This study used a single factor randomized block design (RAK) with non-mulch treatment (M0) and plastic mulch (M1). The data obtained was analyzed at a confidence level of 95% or a real level of 5%. The results showed daily groundwater content tended to be higher on plastic mulch treatment. The treatment of plastic mulch has a real effect on the temperature and content of groundwater. The real difference is in the height of the plant at the age of 8 MST, and the number of leaves at the age of 2 MST and 8 MST. The treatment of plastic mulch has a real effect on the weight of the fruit.
Keyword: rainfall, moisture content, plastic mulch, production, soil temperature

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: 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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