Black locust (Robinia pseudoacacia) is a native species from North America and it has spread to Europe and Asia. Black locust is also one species used for land rehabilitation in semiarid and arid areas. However, adaptability of black locust on their distribution area is quite disturbing due to its invasive potential that tends to suppress the growth of native plants. The purpose of this study is to examine the effect of drought stress through watering volume and watering intervals treatments on physiological behavior and growth of black locust seedlings, and to analyze the level of black locust on drought tolerance through water use efficiency (WUE) character and chlorophyll content. The watering volumes are 30-40 % of field capacity representing drought conditions and 70-80 % of field capacity representing good water conditions, while the watering intervals are 1, 3 and 7 days. Trend analysis is used to analyze the data. The results indicate that the lower watering volume (30-40 %) and the longer the watering interval (for 7 days), the lower the photosynthesis and transpiration rate, stomatal conductance and growth (height, diameter, shoot dry weight and root) of plants, but the higher the WUE and chlorophyll content. Increasing WUE and chlorophyll content are two indicators indicating that black locust is able to adapt (tolerant) to drought stress situations. Therefore, the use of black locust for dry land reclamation requires special attention and careful strategy to avoid its invasive impact in the future.Keywords: black locust, drought, invasive species, water use efficiency, chlorophyll content. (Liu et al., 2013). Sementara itu, tanaman di luar daerah arid maupun semi arid juga sering mengalami defisit air pada siklus hidupnya (Chaves et al., 2002) yang penyebabnya termasuk perubahan signifikan intensitas dan frekuensi suhu bumi serta pola curah hujan, peningkatan suhu atau penurunan kelembaban yang cepat yang mengakibatkan kondisi defisit air Penurunan tekanan turgor yang bersamaan dengan meningkatnya asam absisat bebas pada daun menyebabkan penyempitan stomata (Nilsen dan Orcutt, 1996). Penutupan dan/atau penyempitan stomata menghambat proses fotosintesis, hal ini menyangkut transportasi air dalam tubuh tanaman dan menurunnya aliran karbondioksida pada daun (Nilsen dan Orcutt, 1996; Zlatev dan Lidon, 2012). INTISARI Black locust (Robinia pseudoacacia) merupakan tanaman asli Amerika Utara dan telah tersebar ke Eropa dan Asia serta menjadi salah satu spesies yang digunakan untuk rehabilitasi lahan semiarid dan arid. Walau demikian, kemampuan adaptasi black locust pada daerah persebarannya cukup meresahkan disebabkan jenis ini memiliki potensi invasif yang cenderung menekan pertumbuhan tanaman asli setempat. Tujuan penelitian ini adalah untuk mempelajari pengaruh cekaman kekeringan berupa volume penyiraman dan interval penyiraman terhadap perilaku fisiologis dan pertumbuhan bibit black locust, serta untuk menganalisis tingkat toleransi black locust terhadap kekeringan melalui karakter efisie...
AbstrakSaat ini pembicaraan publik di sosial media menjadi salah satu hal menarik untuk diteliti. Dari topik pembicaraan itu menghasilkan komentar yang sebagian besar mengandung opini sentimen. Penelitian ini mencoba menganalisis komentar dengan metode analisis vader, yaitu metode analisis lexicon-based berbasis rule-based sentiment analysis. Vader akan menganalisis text berdasarkan lexicon (a library) yang menghasilkan class sentimen berupa positif, negatif, dan neutral dengan tambahan skor total atau compound (combined score). Penelitian ini memanfaatkan Prepocess text yang meliputi transformation, tokenization, normalization, dan filtering yang bertujuan agar text bisa dianalisis oleh Orange Data Mining guna mendapat perbandingan analisis sentimen terhadap T-cash dan Go-pay di sosial media. Dari penelitian yang dilakukan mendapat kesimpulan bahwa T-cash memiliki nilai sentimen positif lebih tinggi dari pada Go-pay dan memiliki sentimen negatif yang lebih rendah dari pada Go-pay. Namun persamaanya T-cash dan Go-pay memiliki kesamaan pola grafik dimana sentimen terbesar adalah neutral, diikuti oleh positif, dan terakhir adalah negative.
This research aims to examine the effect of intellectual capital of earnings quality. Population in this research are manufacturing companies listed in Indonesia Stock Exchange (IDX) in 2014 to 2017. The sample of study was determined by using purposive sampling method, and that total sample 52 manufacturing companies. The data used is secondary data. The technique of collecting data by documentation at www.idx.com. The analytical method used is Panel Regression Analysis with Eviews8 software. The results showed that the variables of Value Added Capital Employed (VACA) had a significant positive effect on Earning quality. Value Added Human Capital (VAHU) had no effect on Earning quality and Structural Capital Value Added (STVA) had no effect on earning quality
Evapotranspiration plays a big role in the hydrology process. Potential Evapotranspiration (PET) always keeps soil moisture available, although an amount of water evaporates through evaporation and transpiration. The Thornthwaite equation uses air temperature and latitude from meteorological observations for estimating PET. Medan City is one of the biggest cities in Indonesia that have a problem with land-use change that affected water balance. This study is to estimate the PET and to learn the water balance in Medan City. The monthly temperature data for the period 2011-2020 is collected from three meteorological stations for estimating PET using the Thornthwaite equation. The highest monthly temperature is in Belawan Maritime Meteorological Station yet the lowest rainfall. The trends of PET depend on the month. The highest PET in Jan.-Apr. and Sep.-Dec. are in Belawan Maritime Meteorological Station, while the highest PET in May-Aug. is in Indonesia Agency for Meteorology Climatology and Geophysics Region I Medan. The P-PET has shown negative and positive values. The lowest P-PET is found in Belawan Maritime Meteorological Station in March and the highest P-PET is found in Indonesia Agency for Meteorology Climatology and Geophysics Region I Medan in October.
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