Judul: Vulnerability Assessment of Chilli Farmers with IPCC AR5 Approach (Case Study: Citapen Village, Ciawi District, Bogor Regency)
Abstrak: Pertanian hortikultura memegang peran penting dalam perekonomian Indonesia dengan kontribusinya terus meningkat terhadap PDB. Khususnya tanaman sayuran, berkontribusi terhadap ketahanan pangan dan gizi dimana permintaannya diproyeksikan akan terus meningkat. Namun, pengembangan pertanian hortikultura menghadapi berbagai tantangan, salah satunya adalah perubahan iklim yang dapat mengancam ketersediaan produk hortikultura. Oleh karena itu, diperlukan strategi adaptasi dan mitigasi perubahan iklim. Penelitian ini bertujuan untuk menilai kerentanan petani cabai di Desa Citapen menggunakan penilaian IPCC AR5. Hasil penelitian menunjukkan bahwa keempat metode pendekatan matematis yang digunakan ((S-AC), ((S+AC)/2), S/AC, Matrix) menghasilkan kesimpulan yang sama, yaitu sebagian besar petani cabai memiliki tingkat kerentanan dengan kategori agak rendah dengan metode terbaik adalah metode pembagian. Beberapa faktor pendorong kerentanan antara lain terkait dengan sistem pengelolaan lahan, penyuluhan pertanian dan kelembagaan kelompok tani yang belum optimal, keterbatasan akses terhadap informasi iklim, termasuk pasar dan modal. Rekomendasi strategi adaptasi yang dapat dilakukan diantaranya peningkatan manajemen lahan dengan jadwal yang lebih terencana, pengembangan sistem pertanian polikultur, pengembangan kapasitas kelompok tani, penerapan teknologi yang lebih optimal, serta perluasan program kampung hortikultura dan sekolah lapang iklim., Horticultural agriculture plays an important role in the Indonesian economy with its growing contribution to GDP. Vegetable crops, in particular, contributes to food security and nutrition where demand is projected to continue to increase. However, the development of horticultural agriculture faces various challenges, one of which is climate change that can threaten the availability of horticultural products. Therefore, climate change adaptation and mitigation strategies are needed. This study aims to assess the vulnerability of chilli farmers in Citapen Village using the IPCC AR5 assessment. The results showed that the four mathematical approach methods used ((S-AC), ((S+AC)/2), S/AC, Matrix) resulted in the same conclusion, namely most of the chilli farmers have a level of vulnerability with a rather low category with the best method is the division method. Some of the factors driving vulnerability are related to land management systems, agricultural extension and farmer group institutions that are not optimal, limited access to climate information, including markets and capital. Recommendations for adaptation strategies that can be carried out include improving land management with a more planned schedule, developing polyculture farming systems, developing the capacity of farmer groups, implementing more optimal technology, and expanding the horticultural village programme and climate field schools.
Keyword: chilli farmers, IPCC-AR5, vulnerability assessment

Judul: Farmers' Preferences for the Attributes of Chilli Seeds in Temanggung Sub-district
Abstrak: Benih unggul berperan penting di era perubahan iklim seperti ini mengingat pengembangan benih unggul ditujukan untuk menghasilkan benih yang bersifat adaptif terhadap perubahan iklim, seperti toleransi terhadap suhu tinggi, kekeringan, dan serangan hama dan penyakit. Strategi adaptasi petani terhadap perubahan iklim, seperti penggunaan varietas benih unggul, telah terbukti memberikan dampak positif terhadap peningkatan produksi pertanian. Meskipun demikian penggunaan benih unggul ditentukan oleh tingkat adopsi dan preferensi petani. Mengingat cabai rawit merupakan salah satu komoditi hortikultura strategis yang terdampak perubahan iklim, maka penelitian yang bertujuan untuk menganalisis preferensi dan minat petani terhadap benih cabai rawit di Kabupaten Temanggung, Jawa Tengah ini melibatkan 317 petani responden dari lima kecamatan : Bansari, Ngadirejo, Bulu, Tlogomulyo, dan Kedu yang dipilih dengan metode purposive sampling. Analisis konjoin menunjukkan bahwa resistensi terhadap hama dan penyakit adalah atribut yang paling penting bagi petani, dengan preferensi tinggi pada benih yang sangat tahan terhadap ancaman tersebut. Selain itu, aksesibilitas untuk memperoleh benih dan harga jual cabai rawit juga menjadi pertimbangan utama. Atribut lain yangdiperhatikan meliputi umur tanaman dan potensi produksi. Temuan ini memberikan implikasi penting bagi pengembang benih dan pembuat kebijakan dalam meningkatkan kesejahteraan petani dan stabilitas ekonomi melalui pengembangan benih cabai rawit yang memenuhi preferensi petani., Improved seeds play an important role in this era of climate change because the development of improved seeds is aimed at producing seeds that are adaptive to climate change, such as tolerance to high temperatures, drought, and pest and disease attacks. Farmers' adaptation strategies to climate change, such as the use of superior seed varieties, have been proven to have a positive impact on increasing agricultural production. However, the use of superior seeds is determined by the level of adoption and farmers' preferences. Considering that cayenne pepper is one of the strategic horticultural commodities affected by climate change, the study aimed to analyze farmers' preferences and interests in cayenne pepper seeds in Temanggung Regency, Central Java, involving 317 respondent farmers from five sub-districts: Bansari, Ngadirejo, Bulu, Tlogomulyo, and Kedu which were selected by purposive sampling method. Conjoin analysis showed that resistance to pests and diseases was the most important attribute for farmers, with a high preference for seeds that are highly resistant to these threats. In addition, accessibility to seeds and the selling price of cayenne pepper were also key considerations. Other attributes considered include plant age and production potential. These findings provide important implications for seed developers and policy makers in improving farmers' welfare and economic stability through the development of cayenne seeds that meet farmers' preferences.
Keyword: Cabai Rawit, hortikultura, cayenne pepper, horticulture, atribut benih, preferensi petani, seed attributes, farmer preferences

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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