Judul: Effect of Water Strees and Leaf Fertilization Interval on the Growth of Katuk (Sauropus androgynous L.) Plants
Abstrak: Katuk (Sauropus androgynus L.) merupakan salah satu jenis sayuran indigenous di Indonesia yang dapat memenuhi kebutuhan nutrisi manusia dan digunakan sebagai obat-obatan herbal. Tanaman yang mengalami cekaman air memerlukan tambahan unsur hara dalam mendukung proses pertumbuhan, salah satunya dengan cara pemupukan. Penelitian bertujuan mengetahui pengaruh cekaman air dan interval pemupukan daun terhadap pertumbuhan tanaman katuk. Rancangan percobaan yang digunakan adalah rancangan split-plot dalam rancangan kelompok lengkap teracak (RKLT) yang terdiri atas 2 faktor yaitu interval pemupukan daun sebagai petak utama dan cekaman air sebagai anak petak. Interval pemupukan daun terdiri dari 3 taraf, yaitu P0 (tanpa pemupukan), P1 (2 minggu sekali), dan P2 (4 minggu sekali) . Faktor cekaman air terdiri dari 4 taraf, yaitu C1 (40% kapasitas lapang (KL)), C2 (60% KL), C3 (80% KL ), dan C4 (100% KL). Penelitian dilakukan dengan 3 ulangan yang diperoleh dari 12 kombinasi, sehingga terdapat 36 satuan percobaan. Cekaman air tidak berpengaruh nyata terhadap pertumbuhan tanaman katuk. Waktu pemupukan daun berpengaruh nyata terhadap parameter jumlah cabang, jumlah daun, dan bobot panen dengan interval 2 minggu sekali. Waktu pemberian pemupukan optimal Interaksi antara cekaman air dan pemupukan daun tidak berpengaruh terhadap pertumbuhan tanaman katuk., Katuk (Sauropus androgynus L.) is one of the indigenous vegetables in Indonesia that can meet human nutritional needs and is used as herbal medicine. Plants experiencing water stress require additional nutrients to support the growth process, one of which is fertilization. The study aimed to determine the effect of water stress and foliar fertilization interval on the growth of katuk plants. The experimental design used was a split-plot design in a completely randomized group design (RKLT) consisting of 2 factors: leaf fertilization interval as the main plot and water stress as a subplot. The foliar fertilization interval consisted of 3 levels, namely P0 (without fertilization), P1 (2 weeks), and P2 (4 weeks). The water stress factor consists of 4 levels, namely C1 (40% field capacity (KL)), C2 (60% KL), C3 (80% KL), and C4 (100% KL). The study was conducted with three replications obtained from 12 combinations so that there were 36 experimental units. Water stress did not significantly affect the growth of katuk plants. The time of foliar fertilization had a significant effect on the parameters of the number of branches, number of leaves, and harvest weight at intervals of 2 weeks. Optimal fertilization time The interaction between water stress and foliar fertilization did not affect the growth of katuk plants.
Keyword: Fertilization interval, growth, katuk, water stress

Judul: Effect of Fertilization Dosage on Growth and  Production of Katuk (Sauropus androgynus) Cuttings Using Fertigation Through  Drip Irrigation
Abstrak: Keberadaan tanaman indigenous dapat menambah pilihan jenis sayuran sebagai konsumsi masyarakat. Salah satu tanaman yang masuk dalam tanaman indigenous adalah katuk. Untuk menunjang pertumbuhan tanaman katuk yang maksimal diperlukan adanya aplikasi pemupukan dan penyiraman yang efisien. Penelitian ini bertujuan mengetahui dosis pemupukan yang optimal pada budidaya katuk. Kegiatan penelitian dilaksanakan mulai bulan November 2022 hingga April 2023 di Kebun Percobaan Leuwikopo. Percobaan dilakukan dengan metode rancangan kelompok lengkap teracak sebanyak tiga kali ulangan. Penelitian terdiri dari faktor tunggal yaitu dosis pupuk N, P, dan K dengan lima taraf dosis (0%, 50%, 100%, 150%, 200%). Hasil penelitian menunjukkan bahwa pengaruh dari pemupukan tidak memberikan respon yang nyata, kecuali pada peubah tinggi cabang pada umur tanaman 10-13 MST. Meskipun tidak berpengaruh nyata, terdapat indikasi bahwa bobot basah, bobot daun, dan produktivitas total akan meningkat seiring peningkatan dosis pupuk yang diberikan., The existence of indigenous plants can increase the choice of vegetables for public consumption. One of the indigenous plants is katuk. To support the maximum growth of katuk plants, efficient fertilization and watering applications are needed. This study aims to determine the optimal dose of fertilization in katuk cultivation. Research activities were carried out from November 2022 to April 2023 at the Leuwikopo Experimental Garden. The experiment was conducted using a randomized complete group design method with three replications. The research consisted of a single factor, namely the dose of N, P, and K fertilizers with five dose levels (0%, 50%, 100%, 150%, 200%). The results showed that the effect of fertilization did not give a real response, except for the variable of branch height at plant age 10-13 weeks after planting. Although not significantly affected, there are indications that wet weight, leaf weight, and total productivity will increase as the dose of fertilizer applied increases.
Keyword: indigenous vegetables, inorganic fertilizer, productivity

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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