Judul: Optimization of Planting Time for Three Varieties of Cayenne Pepper (Capsicum frustencens L.) in an Intercropping System with Sweet Corn (Zea mays L.)
Abstrak: Cabai rawit (Capsicum frutescens L.) adalah tanaman hortikultura yang memiliki nilai ekonomi tinggi. Dalam budidaya cabai, alih fungsi lahan menyebabkan penurunan luas panen. Salah satu cara untuk mengatasi masalah ini adalah dengan menerapkan pola tanam tumpangsari di lahan yang berada di bawah tegakan pohon atau dengan menanam tanaman cabai di lahan yang ditanam jagung. Mencari waktu tanam yang presisi dan varietas yang sesuai pada pola tanam tumpangsari merupakan tujuan dari penelitian ini. Penelitian ini menggunakan rancangan petak tersarang (nested design) dengan 2 faktor perlakuan yaitu waktu tanam dengan empat taraf yaitu kontrol: monokultur cabai rawit, 0, 4, 6 minggu setelah tanam jagung (MSJ) sebagai petak utama dan varietas cabai yaitu Bonita, Shadiva, dan Lobita sebagai anak petak. Pelaksanaan penelitian meliputi penyemaian, pengolahan lahan, penanaman, pemeliharaan, dan panen. Hasil dari penelitian ini menunjukan waktu tanam 0 MSJ berpengaruh signifikan pada peningkatan tinggi tanaman terutama pada varietas Shadiva dan menunjukan indikasi etiolasi akibat periode nanungan yang lebih lama dibandingkan waktu tanam lainnya. Nilai produktifitas pada waktu tanam 4 MSJ dan varietas Bonita, dan penurunan penyebaran gemini virus (Geminiviradae) pada 4 MSJ dibandingkan kontrol. Penggunaan waktu tanam yang sesuai dengan kombinasi varietas yang tepat dapat meningkatan nilai produktifitas serta menekan penyebaran penyakit tanaman dan dapat menjadi salah satu upaya untuk menerapkan pertanian berkelanjutan berbasis ramah lingkungan dan meningkatan penghasilan petani., Cayenne pepper (Capsicum frutescens L.) is a high economic value horticultural crop. In chili cultivation, land conversion leads to a decrease in the area under cultivation. One way to overcome this problem is to use intercropping on land under tree stands or to plant chili on land planted with maize. Finding a precise planting time and suitable varieties in intercropping patterns is the purpose of this study. This research utilized a nested design with two treatment factors, namely planting time with four levels: control (cayenne pepper monoculture), 0, 4, and 6 weeks after maize planting (MSJ) as the main plot and chili varieties, namely Bonita, Shadiva and Lobita as subplots. The research implementation includes sowing, soil preparation, planting, maintenance, and harvesting. The results of this study indicate a significant influence of planting time at 0 MSJ on the increase in plant height, particularly in the Shadiva variety, and suggest the possibility of etiolation resulting from prolonged shading periods compared to other planting times. The results indicated that the Bonita variety exhibited higher productivity values at the 4 MSJ planting time. In contrast, the control exhibited a higher incidence of the Gemini virus (Geminiviridae) at the same planting time. The optimal selection of planting time, in conjunction with the most suitable varieties, can enhance productivity and suppress the spread of plant diseases, thereby promoting sustainable agricultural practices that are environmentally friendly and increasing farmers' income.
Keyword: agroforestry, geminivirus, smart farming, sustainability, shading

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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