Kajian Pemangkasan Pucuk Terhadap Pertumbuhan Dan Produksi Baby Mentimun (Cucumis Sativus L)

Mentimun adalah salah satu hortikultura yang mempunyai prospek pasar yang menjanjikan. Berdasarkan data BPS menunjukkan produktivitas mentimun di Indonesia terus menurun dari tahun ke tahun. Upaya untuk meningkatkan produksi mentimun terus dilakukan, diantaranya dengan pemangkasan. Tujuan penelitian ini yaitu untuk mengetahui pengaruh pemangkasan pucuk terhadap pertumbuhan dan produksi tanaman mentimun. Metode penelitian menggunakan Rancangan Acak Kelompok (RAK) sederhana terdiri dari 12 perlakuan : P0 = tanpa pemangkasan, P1 = pemangkasan pucuk setelah ruas ke 3 seluruh cabang lateral, P2 = pemangkasan pucuk ruas ke 5 pada batang utama, P3 = pemangkasan pucuk ruas ke 10 pada batang utama, P4 = pemangkasan pucuk ruas ke 15 pada batang utama, P5 = pemangkasan pucuk ruas ke 20 pada batang utama, P6 = pemangkasan pucuk ruas ke 25 pada batang utama, P7 = pemangkasan pucuk ruas ke 5 pada batang utama dan setelah ruas ke 3 pada seluruh cabang lateral, P8 = pemangkasan pucuk ruas ke 10 pada batang utama dan setelah ruas ke 3 pada seluruh cabang lateral, P9 = pemangkasan pucuk ruas ke 15 pada batang utama dan setelah ruas ke 3 pada seluruh cabang lateral, P10 = pemangkasan pucuk ruas ke 20 pada batang utama dan setelah ruas ke 3 pada seluruh cabang lateral, dan P11 = pemangkasan pucuk ruas ke 25 pada batang utama dan setelah ruas ke 3 pada seluruh cabang lateral. Hasil penelitian : pemangkasan setelah ruas ke 3 seluruh cabang lateral (P1) meningkatkan persentase bunga betina dan jumlah buah per tanaman dibandingkan perlakuan tanpa dipangkas

Pengaruh Berbagai Media Tanam Terhadap Pembibitan Bud Chip Tanaman Tebu (Saccharum Officinarum L.) Varietas Bl

Perbanyakan tanaman tebu yang banyak dilakuakan hingga saat ini berupa bagal, bud chip, dan bud sett. Bud chip adalah perbanyakan bibit tebu yang menggunakan satu mata tunas yang dipindahkan ke kebun dalam bentuk tunas dalam usia 2 - 2,5 bulan. Penelitian disusun menggunakan Rancangan Acak Kelompok Sederhana (RAK) yang terdiri dari 10 perlakuan dengan 3 kali ulangan. Pada hasil penelitian me-nunjukkan bahwa penggunaan kompos blotong dan abu ketel dapat menjadi alternatif media tanam untuk pembibitan bud chip tanaman tebu. Hasil penelitian menunjukkan penggunaan media tanam kompos blotong dan abu ketel memberikan respon yang berbeda pada parameter pengamatan persentase perkecambahan, tinggi tanaman, jumlah daun dan berat kering total tanaman. Perlakuan media tanam kompos blotong dan abu ketel pada M1, M2, M3, M4, dan M5 menunjukkan persentase perkecambahan yang sama dengan media tanam M0 yaitu tanah dan kotoran kambing (4:1). Selain itu pada parameter pengamatan tinggi tanaman perlakuan media tanam kompos blotong dan abu ketel pada M2, M4, M6 dan M8 memiliki tinggi tanaman lebih baik dibandingkan perlakuan media tanam M0. Pada pengamatan bobot kering total tanaman perlakuan media tanam kompos blotong dan abu ketel pada M1, M2, M4, M5, M6 dan M7 memiliki hasil lebih baik dari perlakuan media tanam M0. Dari hasil penelitian tersebut perlakuan media tanam M2 dengan komposisi media tanah dan kompos blotong (1:1) memberikan hasil yang paling baik pada pembibitan bud chip tanaman tebu dibandingkan perlakuan yang lain

Shifting donor-acceptor photoluminescence in N-doped ZnO

We have grown nitrogen-doped ZnO films grown by two kinds of epitaxial methods on lattice-matched ScAlMgO$_4$ substrates. We measured the photoluminescence (PL) of the two kinds of ZnO:N layers in the donor-acceptor-pair transition region. The analysis of excitation-intensity dependence of the PL peak shift with a fluctuation model has proven that our observed growth-technique dependence was explained in terms of the inhomogeneity of charged impurity distribution. It was found that the inhomogeneity in the sample prepared with the process showing better electrical property was significantly smaller in spite of the similar nitrogen concentration. The activation energy of acceptor has been evaluated to be $\approx 170$ meV, which is independent of the nitrogen concentration.Comment: 4 pages, 3 figures, 1 table, RevTeX4, to appear in the July issue of J. Phys. Soc. Jp

Multi-mode storage and retrieval of microwave fields in a spin ensemble

A quantum memory at microwave frequencies, able to store the state of multiple superconducting qubits for long times, is a key element for quantum information processing. Electronic and nuclear spins are natural candidates for the storage medium as their coherence time can be well above one second. Benefiting from these long coherence times requires to apply the refocusing techniques used in magnetic resonance, a major challenge in the context of hybrid quantum circuits. Here we report the first implementation of such a scheme, using ensembles of nitrogen-vacancy (NV) centres in diamond coupled to a superconducting resonator, in a setup compatible with superconducting qubit technology. We implement the active reset of the NV spins into their ground state by optical pumping and their refocusing by Hahn echo sequences. This enables the storage of multiple microwave pulses at the picoWatt level and their retrieval after up to $35 \mu$s, a three orders of magnitude improvement compared to previous experiments.Comment: 8 pages, 5 figures + Supplementary information (text and 6 figures

Polarity in GaN and ZnO: Theory, measurement, growth, and devices

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Rev. 3, 041303 (2016) and may be found at https://doi.org/10.1063/1.4963919.The polar nature of the wurtzite crystalline structure of GaN and ZnO results in the existence of a spontaneous electric polarization within these materials and their associated alloys (Ga,Al,In)N and (Zn,Mg,Cd)O. The polarity has also important consequences on the stability of the different crystallographic surfaces, and this becomes especially important when considering epitaxial growth. Furthermore, the internal polarization fields may adversely affect the properties of optoelectronic devices but is also used as a potential advantage for advanced electronic devices. In this article, polarity-related issues in GaN and ZnO are reviewed, going from theoretical considerations to electronic and optoelectronic devices, through thin film, and nanostructure growth. The necessary theoretical background is first introduced and the stability of the cation and anion polarity surfaces is discussed. For assessing the polarity, one has to make use of specific characterization methods, which are described in detail. Subsequently, the nucleation and growth mechanisms of thin films and nanostructures, including nanowires, are presented, reviewing the specific growth conditions that allow controlling the polarity of such objects. Eventually, the demonstrated and/or expected effects of polarity on the properties and performances of optoelectronic and electronic devices are reported. The present review is intended to yield an in-depth view of some of the hot topics related to polarity in GaN and ZnO, a fast growing subject over the last decade