Judul: Harvest and Post-Harvest Handling of Rose (Rosa hybrid L.) as Cut Flower at Paul van der Hulst Rozenkwekerij BV, Limburg, The Netherlands
Abstrak: Rose has a beautiful appearance and distinctive fragrant aroma. Rose is called the queen of flower. Rose can be used as a cut flower, garden flower, rose petals, and as cosmetic ingredient. Rose plants have many functions including food and beverage ingredients, fragrance, traditional equipment, religious ceremonies, and for indoor decoration. The problem which is often experienced in cut flower especially rose is very short of flower vase life. The efforts that can be done to increase flower production both in quality and quantity are to learn how to handle harvest and post-harvest rose properly and correctly. This internship aims to learn about harvest and post-harvest handling of rose in the Netherlands. The data that had been collected was analyzed quantitatively and descriptively. The data was taken of two varieties, namely Jumilia and Karenza The data that had been collected was analyzed quantitatively and descriptively. The primary and secondary quantitative (numeric) data was analyzed by quantitative analysis using the mean and standard error with Microsoft Office Excel 2013 and t-student test at 5% level with Minitab 16.2.1. The qualitative data was analyzed by using descriptive analysis. The criteria for roses that ready to be harvested are the center of the flower is already slightly open and the petals are little blooms. The techniques to cut rose that ready to be harvested are by cutting the stem and leaving 1-2 cm from node of the plant that are ready to be harvested, and from the first to the third harvest is done by leaving 3 to 4 nodes to increase productivity. Roses vase life in Paul van der Hulst Rozenkwekerij BV were determined by knowing the best time to harvest roses and how to store roses in the cold storage room. The vase life of roses is affected by the cultivar. Jumilia cultivar has a bigger flower and stem length size than Karenza cultivar. The vase life of Jumilia cultivar is longer than Karenza cultivar.
Keyword: criteria, cultivar, Jumilia, Karenza, production

Judul: Cultivation, Harvest, and Postharvest of Hortensia Cut Flower (Hydrangea macrophylla) at Kwekerij Figaro B.V., Naaldwijk, South Holland
Abstrak: H. macrophylla merupakan bunga potong yang populer di pasar Eropa karena keindahannya. Vase life menjadi penentu bagi keputusan konsumen dalam membeli bunga potong karena pendeknya vase life dapat menurunkan kepuasan konsumen dan mengurangi nilai estetikanya. Kegiatan magang bertujuan meneliti lebih lanjut proses budidaya H. macrophylla di Kwekerij Figaro B.V. serta mendapatkan informasi mengenai konsentrasi larutan perendam yang tepat untuk mendapatkan vase life H. macrophylla ‘Mammoet’ yang optimum. Proses budidaya yang diamati meliputi kondisi greenhouse, irigasi, pemupukan, pengendalian OPT, produksi, dan pemasaran. Produksi dan penjualan H. macrophylla ‘Mammoet’ mengalami penurunan yang signifikan di periode 2021–2023 dikarenakan masalah pada sistem pengairan yang perlu diperbaiki di periode budidaya berikutnya. Penelitian larutan perendam vase life menggunakan RKLT faktorial dua faktor, yakni larutan Chrysal Grow 20 dan Vaselife Universal Flower Food. Vase life dengan hari paling panjang dan efisien terdapat pada konsentrasi 8 mL L-1 Chrysal Grow 20. Penambahan Vaselife Universal Flower Food 1 mL L-1 pada bunga membuat vase life terpanjang, yakni 9,18 hari, lebih panjang 1,95 hari dibanding perlakuan air (kontrol). Interaksi antar dua larutan menunjukkan hasil yang tidak nyata., H. macrophylla is a popular cut flower in the European market due to its aesthetics. Vase life is a determining factor for consumer decisions when purchasing cut flowers because a short vase life can reduce consumer satisfaction and diminish its aesthetic value. The internship activity aims to further investigate the cultivation process of H. macrophylla at Kwekerij Figaro B.V. and obtain information about the appropriate vase life solution dosage to achieve optimal vase life for H. macrophylla 'Mammoet'. The observed cultivation process includes greenhouse conditions, irrigation, fertilization, pest and disease control, production, and marketing. The production and sales of H. macrophylla 'Mammoet' experienced a significant decline in the period 2021–2023 due to issues with the irrigation system that need to be addressed in the subsequent cultivation periods. The study on vase life solutions used a two-factor RCB design, namely Chrysal Grow 20 and Vaselife Universal Flower Food solutions. The longest and most efficient vase life solution was found at a concentration of 8 mL L-1 Chrysal Grow 20. The addition of 1 mL L-1 Vaselife Universal Flower Food resulted in the longest vase life, which is 9.18 days or 1.95 days longer than the water treatment (control). The interaction between the two solutions showed statistically insignificant results.
Keyword: cultivation, greenhouse, hydrangea, vase life

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
Keyword: