Judul: The Effect of the Combination of Coconut Water and GA3 on the Grow of Coconut Orchids (Maxillaria tenuifolia)
Abstrak: Maxillaria tenuifolia merupakan tanaman anggrek yang memiliki ciri khas pada bunganya yang beraroma manis. Penelitian ini bertujuan untuk mengetahui pengaruh kombinasi air kelapa dan GA3 terhadap pertumbuhan anggrek kelapa (Maxillaria tenuifolia). Penelitian dilaksanakan pada bulan November 2022 sampai April 2023 di Gunung Batu, Bogor Barat. Penelitian menggunakan rancangan kelompok lengkap teracak (RKLT) dengan enam perlakuan dan empat ulangan. Perlakuan pertama yakni kontrol (tanpa perlakuan), air kelapa 50% + GA3 50 ppm, air kelapa 60% + GA3 100 ppm, air kelapa 70% + GA3 150 ppm, air kelapa 80% + GA3 200 ppm, air kelapa 90% + GA3 250 ppm. Setelah 16 minggu setelah tanam (MST) dilakukan pengujian kandungan unsur hara N, P, K, dan C. Kombinasi air kelapa dan GA3 berpengaruh nyata pada parameter pengamatan pertambahan panjang daun, pertambahan jumlah pseudobulbs, pertambahan diameter pseudobulbs, pertambahan tinggi pseudobulbs, dan pertambahan tinggi tanaman, namun tidak memberi pengaruh nyata pada parameter pengamatan pertambahan jumlah daun. Pemberian air kelapa dan GA3 menghasilkan nilai C/N rasio yang tinggi sebagai indikator pendorong terjadinya induksi pembungaan., Maxillaria tenuifolia is an orchid plant with a characteristic sweet fragrance flower. This study aims to determine the effect of the combination of coconut water and GA3 on the growth of coconut orchids (Maxillaria tenuifolia). The research was conducted from November 2022 to April 2023 in Gunung Batu, West Bogor. The study used a randomized complete block design with six treatments and repeated four times. The treatments were control (without induction), coconut water 50% + GA3 50 ppm, coconut water 60% + GA3 100 ppm, coconut water 70% + GA3 150 ppm, coconut water 80% + GA3 200 ppm, coconut water 90% + GA3 250 ppm. After 16 weeks after planting (WAP), the nutrient concentration of N, P, K, and C was analyzed. The combination of coconut water and GA3 significantly affected leaf length increase, pseudobulbs increase, pseudobulbs diameter increase, pseudobulbs height increase, and plant height increase. The application of coconut water and GA3 produces a high C/N ratio as an indicator driving the induction of flowering.
Keyword: C/N rasio, hormon, konsentrasi, pseudobulb, unsur hara

Judul: Shoot Proliferation and Pseudobulb Induction of Coelogyne pandurata Lindley Orchid on MS Medium with Addition of Coconut Water and Sugar
Abstrak: Coelogyne pandurata Lindley merupakan flora endemik khas Kalimantan Timur. Perbanyakan konvensional sulit dilakukan untuk pengadaan bibit berkualitas secara massal dalam waktu singkat sehingga dilakukan perbanyakan secara in vitro. Penelitian ini bertujuan mempelajari pengaruh pemberian air kelapa dan gula pada media MS terhadap daya proliferasi tunas dan pembentukan bulb anggrek hitam secara in vitro. Percobaan disusun dengan Rancangan Kelompok Lengkap Teracak (RKLT) faktorial dua faktor menggunakan bahan tanam planlet Coelogyne pandurata L. Faktor pertama adalah konsentrasi air kelapa: 0 (kontrol), 50, 100, 150, dan 200 ml/l; faktor kedua adalah konsentrasi gula: 0 (kontrol), 30, 40, dan 50 g/l. Hasil penelitian menunjukkan bahwa interaksi antara penambahan air kelapa dengan gula berpengaruh nyata meningkatkan jumlah tunas namun tidak nyata mempengaruhi parameter lainnya dengan jumlah rata-rata tunas terbanyak dihasilkan dari perlakuan air kelapa 150 ml/l dengan gula 40 g/l yaitu 1,70 tunas per eksplan. Perlakuan air kelapa 150 ml/l dengan gula 40 g/l menginduksi proliferasi tunas terbaik namun tidak berbeda nyata dengan beberapa perlakuan lain., Coelogyne pandurata Lindley is an endemic orchid from East Kalimantan. Conventional propagation is difficult to obtain quality seeds in a relative short time, so in vitro propagation is the best choice. This research aims to study the effect of coconut water and sugar on the shoot proliferation and pseudobulb formation of black orchids in vitro. The experiment was designed using a factorial two-factors Randomized Complete Block Design using the propagule of Coelogyne pandurata Lindley’s plantlet. The first factor is the concentration of Coconut Water (CW): 0 (control), 50, 100, 150, and 200 ml/l; the second factor is the sugar concentration: 0 (control), 30, 40, and 50 g/l. The results showed that the interaction of 150 ml/l CW with 40 g/l sugar had a significant effect on increasing shoot proliferation, namely 1.70 shoots per explant. Treatment of 150 ml/l CW with 40 g/l sugar induced the best shoot proliferation but was not significantly different compared with several other treatments.
Keyword: konsentrasi, sukrosa, Kalimantan Timur, sitokinin

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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