Judul: Evaluasi Karakter Vegetatif Hoya (Apocynaceae) di Kebun Raya Bogor
Abstrak: Hoya is epiphyte, lithophyte plant, or shrub. Information of morphological diversity is essential to it’s development as an ornamental plant. The aim of this research was to study the morphological diversity of vegetative characters of Hoya that are collected in Bogor Botanical Garden, in order to facilitate identification in the field. This research provides the diversity of vegetative characters of Hoya as one of the library reference, and provides a Hoya identification key based on vegetative characters. Twenty six Hoya species were morphologically characterized their vegetative organs. The data then were tabulated, and used for constructing an identification key. The results showed that Hoya has variation in several vegetative characters i.e shape, size, base and tip of the leaf, vein shape of leaf, leaf blade surface (indumentum), leaf blade color, petiole shape, indumentum, size and color of the stem. The best characters for distinguishing among Hoya species were the form of the leaf blade and leaf venation. Some species have some unique characters that can be used to distinguish among species of Hoya, for example H. imbricata has imbricate leaf arrengement, reniform shape and purple abaksial surface. The leaf venation of H. finlaysonii is pinnate that has contrast color between venation and blade. The specific features of other species will be discussed further in this paper.
Keyword: identification key, vegetative characters, morphology, Hoya

Judul: Study of Growth and Flowering of Several Indonesian Hoyas (Hoya sp.) Indonesia
Abstrak: Indonesia merupakan negara mega-biodiversity dengan banyak keanekaragaman hayati. Hoya menjadi salah satu kekayaan milik Indonesia dari famili Apocynaceae yang secara alami tumbuh merambat di bawah naungan hutan tropika. Banyaknya spesies hoya belum semuanya diikuti dengan kelengkapan informasi mengenai siklus hidup dan pembungaan, maupun cara budidaya yang optimal. Penelitian ini bertujuan untuk menambah informasi mengenai masa pertumbuhan vegetatif dan generatif hoya, serta morfologi dan anatomi daun hoya. Penelitian dilaksanakan di greenhouse Kebun Percobaan Leuwikopo dan Laboratorium Mikroteknik Program Studi Agronomi dan Hortikultura pada Desember 2022 hingga Juli 2023. Pengumpulan informasi dilakukan melalui tahap pengamatan dan pengukuran dengan parameter vegetatif berupa panjang batang, jumlah batang, jumlah daun, jumlah buku, dan parameter generatif berupa jumlah kuntum bunga, diameter cabang, dan periode pembungaan, serta parameter morfologi dan anatomi daun berupa bentuk daun, bentuk pangkal dan ujung daun serta keberadaan jaringan epidermis, dan jaringan mesofil. Hasil yang didapatkan menunjukkan perbedaan pertumbuhan vegetatif maupun generatif tiap spesies hoya, terutama pada kecepatan tumbuh dan durasi munculnya bunga. Perbedaan juga ditemukan pada bentuk, tipe dan struktur anatomi daun hoya., Indonesia is a mega-biodiversity country with rich biodiversity. Hoya, a member of the Apocynaceae family, is one of tropical epiphytic vines naturally growth under tropical forest. The existing species of hoya not accompanied by complete information regarding the life cycle and flowering yet, as well as optimal cultivation methods. This study aims to add information on the vegetative and generative growth stages of hoya, as well as the morphology and anatomy of its leaves. The research was conducted at the greenhouse of Leuwikopo Experimental Farm and the Microtechnic Laboratory of the Department of Agronomy and Horticulture from December 2022 to July 2023. Data collected by observation and measurement, encompassing vegetative parameters such as branch length, number of branches, number of leaves, and number of nodes, and generative parameters including number of flower buds, branch diameter, and flowering period. Additionally, morphological and anatomical parameters of the leaves, such as leaf shape, base and tip shape, and the existence of epidermal and mesophyll tissues were recorded. The results revealed variations in the vegetative and generative growth among different species of hoya, especially in growth speed and duration of flower appearance. The differences are also found in the shape, type and anatomical structure of hoya leaves.
Keyword: anatomi, generatif, hoya, morfologi, vegetatif

Judul: Dynamic New Keynesian Model for Unemployment and Inflation Rate.
Abstrak: This paper deals with a scientific analysis of the equilibrium level of hiring, employment and unemployment. The basic model being used is a standard new Keynesian model, which states that utility function depends on consumptions and working hours. Utility maximization refers to a standard labour supply equation, with the marginal cost’s dynamics on new Keynesian model simply reflects movements in real wages and productivity. Furthermore, trade-off between output and inflation stabilization can be considered using the new Keynesian Phillips curve. Dynamic general equilibrium model is a model that can be used to study interactions between market imperfections and nominal rigidities, which is capable of overcoming the main shortcoming of the standard new Keynesian model. In the general equilibrium model there are three groups of the economy agents, namely households, firms and monetary authority. The results of this research science that bargaining processes between firms and workers will yield optimal wage. Increase in labour will cause wages to fall, but the unemployment rate can be reduced. An increase in the firm’s monopoly power will shift the labour demand curve downward, which will reduce the number of workers that firm is willing to hire for any given bargained wage.
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