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Soil Bacterial Diversity and Productivity of Coffee - Shade Tree Agro-ecosystems Evizal, Rusdi; Tohari, .; Prijambada, Irfan Dwidja; Widada, Jaka; Widianto, Donny
JOURNAL OF TROPICAL SOILS Vol. 17 No. 2: May 2012
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2012.v17i2.181-187

Abstract

Coffee productions should have environmental value such as providing high soil microbial diversity while producing high yield. To examine that purposes, two experimental plots were constucted at benchmark site of Conservation and Sustainable Management of Below-Ground Biodiversity (CSM-BGBD), in Sumberjaya Subdistrict, West Lampung, Indonesia, during 2007-2010. Types of coffee agro-ecosystem to be examined were Coffea canephora with shade trees of Gliricidia sepium, Erythrina sububrams, Michelia champaca, and no shade. Two plots were constructed at 5-years-coffee and 15-years-coffee. Diversity of soil bacteria was determined based on DNA finger printing of total soil bacteria using Ribosomal Intergenic Spacer Analysis (RISA) method. The results showed that: (1) For mature coffee (15 years old), shade-grown coffee agro-ecosystems had higher soil bacterial diversity than those of no shade coffee agro-ecosystem, (2) Shaded coffee agro-ecosystems were able to conserve soil bacterial diversity better than no-shade coffee agro-ecosystem. Soil organic C and total litter biomass had positive effect on soil bacterial diversity, (3) Types of agro-ecosystem significantly affect the bean yield of 15 years coffee. Coffee agro-ecosystems shaded by legume trees had higher yield than those of non-legume shade and no shade coffee agro-ecosystem, (4) Shannon-Weaver indices of soil bacterial diversity together with weed biomass and N content of coffee leaf had positive effect on coffee bean yield.
Exploration of Nematophagous Fungi from Coffee Rhizosphere Soil and their Potential as Biological Control Agents against Root-lesion and Root-knot Nematodes Indarti, Siwi; Aldina, Rinda Fajrin; Widianto, Donny; Prijambada, Irfan Dwidya; Maharani, Rina; Kurniasari, Irianti; Waele, Dirk De
Jurnal Perlindungan Tanaman Indonesia Vol 29, No 2 (2025): In Progress
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jpti.102469

Abstract

Root-lesion and root-knot nematodes are amongst the most important pathogens of coffee and can cause substantial yield losses and quality reductions. Environmental and health concerns concerning the use of chemical pesticides have increased the need for alternative management strategies against plant-parasitic nematodes. The aim of our study was to isolate and identify nematophagous fungi from nematode-infested coffee production areas and evaluate their potential as biocontrol agents. Our study was carried out in two stages: 1) fungi isolation and evaluation of their ability to affect eggs or vermiform developmental stages of root-lesion and root-knot nematodes; 2) identification of fungal isolates to species level. Eleven fungal isolates were able to affect either the nematode eggs or the vermiform developmental stages. The ability of these fungi to produce extracellular enzymes were also evaluated. This study highlights Indonesian nematode infected coffee rhizosphere soils as a rich source of nematophagous fungi, with eleven isolates showing promises to be used for integrated pest management strategies. Future work should assess field efficacy under local conditions while monitoring impacts on soil food webs and non-target organisms.
Endophytic Bacteria From Banana Plants Improves The Growth of Rice (Oryza sativa) and Maize Plants (Zea mays) Sidiq, Yasir; Silviani, Defina Anggita; Rahayu, Triastuti; Saputra, Alanindra; Wahibah, Ninik Nihayatul; Widianto, Donny
Al-Kauniyah: Jurnal Biologi Vol. 18 No. 1 (2025): AL-KAUNIYAH JURNAL BIOLOGI
Publisher : Department of Biology, Faculty of Science and Technology, Syarif Hidayatullah State Islami

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/kauniyah.v1i1.37884

Abstract

AbstractFive isolates of endophytic bacteria from the roots of klutuk and ambon banana plants produce indole acetic acid (IAA) hormone. However, the evidence of its potential as Plant Growth Promoting Bacteria (PGPB) has not been observed. Therefore, this study aims to determine the effect of bacterial isolate to increase the growth of rice and maize plants. The growth rates of bacterial isolates were measured before the inoculation into the plant root. The root inoculation was performed following a complete randomized design. Root inoculation was carried out using 5 isolates of endophytic bacteria in rice and maize plant seedlings, and the process was repeated 15 times (n=15). The growth of rice and maize plants was monitored from 1st day after planting (dap) to the 14th dap. The collected data were analyzed by student t-test with a significant level of 5% (a= 0.05). The results showed that the logarithmic phase of all isolates was reached at 4 to 16 hours and K10, K25, K35, K111, and A41 isolates increased the height of plants while the K111 isolate can significantly increase the plant height compared to the control. This experiment revealed that the endophytic bacteria from banana plants increase the rice and maize plant’s growth.AbstrakLima isolat bakteri menghasilkan hormon indole acetic acid (IAA) yang berpotensi memacu pertumbuhan tanaman. Namun, bukti empiris potensinya sebagai Plant Growth Promoter Bacteria (PGPB) belum didapatkan. Penelitian ini bertujuan untuk mengetahui pengaruh isolat bakteri terhadap peningkatan pertumbuhan padi dan jagung. Penelitian ini menggunakan metode eksperimen dengan desain rancangan acak lengkap dan setiap perlakuan diulang 15 kali (n= 15). Hasil pertumbuhan tanaman yang diinokulasi dengan isolat bakteri masing-masing dibandingkan dengan perlakuan kontrol. Sebelum perlakuan, tingkat pertumbuhan bakteri endofit diukur sehingga didapatkan fase logaritmik yang cocok untuk dilakukan inokulasi ke akar tanaman. Setelah perlakuan, pertumbuhan tanaman padi dan jagung dipantau dari hari ke-1 setelah tanam (hat) sampai dengan ke-14 hat. Data dianalisis dengan uji t dengan taraf signifikan 5% (α= 0,05). Hasil penelitian menunjukkan bahwa 5 isolat yang berasal dari tanaman pisang mengalami fase logaritmik pada masa inkubasi 4 hingga 16 jam dan semua isolat bakteri meningkatkan tinggi tanaman serta isolat K111 dapat meningkatkan tinggi tanaman secara signifikan dibandingkan dengan kontrol. Penelitian ini mengungkapkan kemampuan bakteri endofit dari tanaman pisang untuk meningkatkan pertumbuhan tanaman.
Penafsiran Filsafat Ilmu Dan Filsafat Hukum Dalam Menghadapi Tantangan Ketatanegaraan Kontemporer Widianto, Donny; Israhadi, Evita Isretno
Innovative: Journal Of Social Science Research Vol. 4 No. 2 (2024): Innovative: Journal Of Social Science Research
Publisher : Universitas Pahlawan Tuanku Tambusai

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31004/innovative.v4i2.9916

Abstract

Penafsiran filsafat ilmu dan filsafat hukum memiliki peran penting dalam menghadapi tantangan ketatanegaraan kontemporer yang kompleks dan multidimensional. Globalisasi, disrupsi teknologi, dan polarisasi politik telah menciptakan lanskap yang rumit bagi pemerintahan dan lembaga hukum di berbagai negara. Dalam konteks ini, filsafat ilmu memberikan wawasan tentang bagaimana mengelola tantangan globalisasi dengan penggunaan bukti empiris dan pengetahuan ilmiah, sedangkan filsafat hukum membantu dalam memahami dasar-dasar moral dan politik dari sistem hukum serta merumuskan prinsip-prinsip yang mengatur interaksi antara negara-negara dalam sistem internasional. Integrasi antara keduanya memungkinkan pengembangan solusi-solusi yang komprehensif untuk membangun masa depan yang lebih stabil, adil, dan berkelanjutan. Dengan melibatkan pendekatan analitis dari filsafat ilmu dan refleksi kritis dari filsafat hukum, kebijakan-kebijakan publik yang responsif dan inklusif dapat dirumuskan. Studi kasus tentang sengketa Laut China Selatan dan legalisasi ganja mengilustrasikan bagaimana integrasi antara kedua bidang pengetahuan ini dapat menghasilkan solusi yang holistik. Langkah-langkah seperti meningkatkan kerjasama lintas-disiplin, memperkuat pendidikan dan pelatihan, serta mendorong penelitian interdisipliner diperlukan untuk memperkuat peran filsafat ilmu dan filsafat hukum dalam menghadapi tantangan-tantangan ketatanegaraan kontemporer
Rhizosphere Bacteria Plumeria acuminata Increases Growth of Zea mays After Root Inoculation Insani, Qori Tsaniyah Ainun; Rahayu, Triastuti; Widianto, Donny; Listiawati, Vina; Mumpuni, Kistantia Elok; Prayitno, Trio Ageng; Sidiq*, Yasir
Jurnal IPA & Pembelajaran IPA Vol 7, No 4 (2023): DECEMBER 2023
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jipi.v7i4.34658

Abstract

The bacteria found in the rhizosphere are called plant growth promoting rhizobacteria (PGPR), namely bacteria that can stimulate plant growth by producing growth hormones, one of which is the hormone indole acetic acid (IAA) which plays a role in regulating plant growth and development. Five isolates of rhizosphere bacteria were isolated on frangipani roots (P26, P31, P36, P37 and P38). Previous research showed that five bacterial isolates were capable of producing the hormone IAA. However, evidence of its potential as a PGPR has not been obtained. Therefore, the aim of this study was to test the effect of inoculation of rhizosphere bacteria on maize plants. The research method uses a quantitative experimental method, namely 15 repetitions for each treatment. Data collection was carried out 1 day after planting (HTS) until the 14th day. Data were analyzed using a 95% confidence student t-test or with a significance level of 5% (a=0.05). This inoculation begins with germinating maize seeds and observing the roots. The germinated maize seeds are then soaked in the bacterial suspension for one hour at room temperature. The results showed that inoculation with isolates P36, P37 and P38 significantly increased the height of maize plants, while isolate P37 significantly increased the number of leaves and root length of corn plants, isolate P38 could significantly increase the number of roots of corn plants.Thus, these results support the evidence that rhizosphere bacteria from frangipani have an effect on increasing the growth of maize plants
The Challenges of Enforcing the Police Code of Ethics in the Ethical Tribunal Procedures for Police Officers Widianto, Donny; Suparno, Suparno
Cognitionis Civitatis et Politicae Vol. 1 No. 6 (2024)
Publisher : Yayasan Adra Karima Hubbi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70177/politicae.v1i6.1832

Abstract

Police code of ethics law enforcement is a crucial aspect in creating a police institution that is professional, accountable, and trusted by the public. This article discusses the problems faced in the procedure for the code of ethics trial for Polri members, with a focus on the law enforcement mechanism for violations of the professional code of ethics in the police. Although there is a clear regulatory framework, including Police Regulation Number 7 of 2022, the implementation of the code of ethics trial is often marred by a lack of transparency and accountability. The trial, which is carried out behind closed doors, results in public distrust of the integrity of the law enforcement process. In addition, the sanctions imposed are often considered disproportionate to the severity of the violation, creating the impression that violators can avoid more severe consequences. This study also highlights other issues that arise, such as the overlap between the code of ethics trial process and criminal justice, as well as the neglect of victims' rights in the legal process. By analyzing these problems, this study provides an effort for the necessary reforms in the Polri Code of ethics and law enforcement mechanism to ensure justice and accountability and increase public trust in the police institution.