Puslit Penelitian Karet E-Journal System Portal
Not a member yet
531 research outputs found
Sort by
DISTRIBUTION OF GLYPHOSATE-RESISTANT GOOSEGRASS (ELEUSINE INDICA) POPULATIONS AND AN ALTERNATIVE HERBICIDE (INDAZIFLAM) TO CONTROL THEM
No full textGoosegrass (Eleusine indica) in rubber plantations in Rambutan Estate, PTPN III has been controlled by using glyphosate continuously for 28 years. It has recently been reported that glyphosate is no longer effective for controlling E.indica in the area. How large the area of glyphosate-resistant goosegrass in the Rambutan Estate and what alternative herbicide as control options can be implemented is never reported. This study aims to determine the distribution of E. indica populations that have evolved to be resistant to glyphosate and the possibility of indaziflam as alternative herbicide to control glyphosate-resistant goosegrass population in the Estate. Seed samples from more than 50 plants in each population which had continuously been exposed to glyphosate for 28 years were collected from 14 different rubber plantation blocks. The fourteen putative glyphosate-resistant goosegrass populations were tested for glyphosate resistance along with sensitive population that was never sprayed with herbicides, for comparison, (collected from the Campus Universitas Sumatera Utara in Medan)). Each population is planted as many as 12 plants per pot with three replicates. Plants at 4- to 5- leaf stage were sprayed with glyphosate with a dose of 480 g a.i. per hectare. Each population is arranged in a complete randomized design. The results of spraying goosegrass collected from 14 different populations indicated that eight populations are "highly resistant" and six are "resistant" to glyphosate. Thus, it was concluded that fourteen goosegrass populations at Rambutan Estate have developed resistance to glyphosate. To determine the effectiveness one of indaziflam as alternative herbicide, one population of the goosegrass was applied with indaziflam (PRE) at doses of 50, 75, 100, 150 g a.i per hectare and a plot without control as a comparison. Indaziflam, at all the rates tried, effectively controlled the glyphosate-resistant population.Keywords: Eleusine indica, distribution, glyphosate, goosegrass, resistanc
STUDY OF THE INTERACTIONS OF A MAJOR RUBBER PARTICLE PROTEIN (REF1) WITH SYNTHETIC PHOSPHOLIPIDS IN LANGMUIR MONOLAYERS
No full textRubber Elongation Factor (REF1) protein is located on the surface of rubber particles (RPs). As a RP-bound and hydrophobic protein, REF1 is suspected to be only partially eliminated by the water washing occurring during latex processing into raw natural rubber (NR) in the form of unsmoked rubber sheet (USS) and could thus affect raw NR properties. In this work, REF1 was identified as an abundant protein of raw NR and biophysical methods were used to describe the organization/structure of REF1 at the surface of RPs interacting with the lipid monolayer surrounding the poly-isoprene core. Therefore, an approach in Langmuir film was implemented to investigate the interactions between recombinant REF1 and synthetic phospholipids (POPC, POPG and POPA) by fluorescence (calcein-leakage measurements), ellipsometry, Brewster angle microscopy, and PM-IRRAS spectroscopy. REF1 was shown to interact differently depending on lipid headgroup type: no interaction with POPC, intermediate interactions with POPG and strong interactions associated to a conformational switch from  -helices to  -sheets with POPA.Keywords: Hevea brasiliensis, rubber particle, langmuir monolayer, rubber elongation factor, synthetic phospholipids
FINANCIAL FEASIBILITY OF LOW FREQUENCY TAPPING SYSTEMS TO DEAL WITH THE BUSINESS CHALLENGE OF RUBBER PLANTATIONS IN INDONESIA
No full textIn present day context, rubber plantations are facing problems of the low rubber price, difficulty in finding workers for tapping and rising the cost of production. Tapping cost is the biggest component in cost of production. Therefore, this study was aimed to analyze financial feasibility of different tapping systems in the mature rubber tapped on B0 panel and H0 B1 panel. Tapping systems comprised varying degree of tapping frequencies and stimulation (ethephon) systems. Financial analysis was based on assessments on the margin revenue and margin costs. Out of 19 tapping systems tested, five systems found to be profitable against the usually practiced once in three day tapping with 2.5% ethephon every two weeks. On the virgin base panel (B0), three systems are available, i.e. two with once in three days tapping using 2.5% ethephon at 10 days interval and 4% ethephon at 2 weeks interval and, another with once in four days tapping using 5% ethephon at 2 weeks interval. In intensified tapping with double cuts (DU), only once in three days tapping was found financially feasible with 4% and 5% ethephon at two weeks intervals on the base panel. Key words :  economic feasibility, partial budget, rubber, tapping system
RELATIONSHIPS BETWEEN CARBON STOCK IN THE RUBBER TREE AND LATEX PRODUCTION
No full textThe relationship between tapping systems and the balance between latex production and carbohydrate availability would be very informative. This present work aims to study the effects of tapping systems on enzyme activities involved with Non-structural carbohydrates (NSCs) dynamic. The result indicated that enzyme activities from RRIM600 with upward tapping was higher from that of downward tapping. This could be partly due to the gradient sucrose along the truck as it is more concentrated in higher position than the lower one. Sucrose synthase was proportional to sucrose content in bark of upward tapping. Meanwhile, Sucrose Phosphate Synthase and Amylase were higher in wood than bark. These enzymes were also significantly higher in upward tapping than downward tapping. Using immunolocalization test, amylase was located in both vascular rays of bark and wood. It was noticed that enzyme activities strongly related to sucrose content while the link with starch content could not be clarified yet. To eventually explain the whole picture of NSC balance and latex production, information of latex production yield and enzyme involved in starch synthesis must be taken into account.Keywords: Non-structural carbohydrates (NSCs), rubber trees (Hevea brasiliensis Muell. Arg.), tapping systems, immunolocalizatio
THE ROLE OF THE INTERNATIONAL TRIPARTITE RUBBER COUNCIL (ITRC) IN STABILIZING NR PRICES
No full textIn 2001, three major producers of Natural Rubber (NR) namely Thailand, Indonesia and Malaysia signed a Declaration to establish a rubber tripartite cooperation under the framework of the International Tripartite Rubber Council (ITRC). The objectives of this cooperation are aimed towards sustainable NR production and implement relevant measures in achieving remunerative NR prices for the wellbeing of rubber smallholders. To assist ITRC, International Rubber Consortium (IRCo) was established in 2004 with the 3 members Governments from ITRC as its shareholders. To achieve a sustainable industry and stabilised NR prices, 3 mechanisms have been established under ITRC and IRCo i.e. Supply Management Scheme (SMS) as a long-term planting programme to ensure sustainable supply, Agreed Export Tonnage Scheme (AETS) and Strategic Market Operation (SMO) which will be implemented whenever the need arises.On top of the above 3 existing mechanisms, various programmes are also currently being implemented as part of the 10-Plan of ITRC/IRCo. These include rubberised road under Demand Promotion Scheme (DPS) and establishment of Regional Rubber Market; providing an alternative rubber futures trading with hedging facilities. ITRC is committed in helping millions of rubber smallholders who are the backbone of this industry. The sustainability of this industry is very crucial as NR is an important raw material in plethora of industries ranging from tyres, latex-based and other industrial and general goods. In the next decade, ITRC will play a greater role to ensure sustainability, remunerative NR prices for smallholders as well as providing fair and less volatile NR prices for our consumers. With Viet Nam on board as a Full Partner of ITRC, our mission and aims look more promising than ever
PENINGKATAN PRODUKSI DAN ANALISIS FINANSIAL PADA BUKA SADAP DENGAN LILIT BATANG > 45 CM UNTUK MENGHADAPI HARGA KARET RENDAH
Get PDFSalah satu upaya untuk menghadapi kondisi harga jual karet yang rendah adalah dengan meningkatkan produktivitas untuk menekan harga pokok dan menghindari kerugian. Peningkatan produktivitas dalam jangka panjang dapat melalui pengoptimalan keragaan tanaman terutama lilit batang dengan menunda buka sadap. Perbedaan kriteria buka sadap di Indonesia dengan negara penghasil karet lain diduga turut menyebabkan perbedaan produktivitas yang terjadi. Penelitian ini bertujuan untuk mengetahui peningkatan laju pertumbuhan lilit batang sebelum dan sesudah tanaman disadap, peningkatan produktivitas dan laba/rugi akibat adanya penundaan buka sadap. Penelitian dilakukan di areal tahun tanam 2010, Galardowo, Kebun Getas, PTPN IX Jawa Tengah dan mulai dilaksanakan pada bulan Oktober 2015 (akhir TBM V) hingga 2017. Rancangan penelitian yang digunakan adalah Rancangan Acak Lengkap dengan faktor tunggal yaitu kelas lilit batang. Parameter yang diamati yaitu lilit batang dan tebal kulit awal, pertumbuhan lilit batang dan tebal kulit tiap bulan, volume lateks, kadar karet kering (K3), dan produksi karet kering per pohon, serta taksasi/proyeksi produksi untuk bulan berikutnya. Poduktivitas tersebut selanjutnya digunakan menghitung analisis finansial buka sadap pada tiap kelas lilit batang. Metode analisis finansial pada penelitian ini menggunakan analisis R/C ratio. Hasil penelitian menunjukkan bahwa buka sadap yang dilakukan pada lilit batang lebih besar dari kriteria normal menunjukkan lebih besar laju pertumbuhan lilit batang dan tebal kulitnya serta lebih tinggi produksinya sehingga keuntungan atau nilai R/C ratio pada saat TM 1 juga semakin besar
SIFAT FISIKA ASPAL MODIFIKASI KARET ALAM PADA BERBAGAI JENIS DAN DOSIS LATEKS KARET ALAM
Get PDFBiopolimer lateks karet alam berpotensi digunakan sebagai bahan aditif dalam pembuatan aspal modifikasi polimer atau aspal karet. Penelitian ini bertujuan untuk mempelajari pengaruh berbagai jenis dan dosis lateks karet alam terhadap sifat fisika aspal karet. Lateks karet alam yang digunakan meliputi lateks karet alam pekat murni, lateks karet alam kationik, dan lateks karet alam yang telah dipravulkanisasi selama 1 dan 4 jam. Aspal sebagai bahan utama dipilih jenis aspal pen 60. Penilaian mutu aspal karet didasarkan pada hasil pengujian penetrasi, titik lembek, daktilitas, indeks penetrasi, uji TFOT, dan elastic recovery. Pencampuran lateks karet alam dalam aspal pen 60 dilakukan pada suhu 140 – 150oC. Dosis penambahan lateks karet alam divariasikan sebesar 3, 5 dan 7% terhadap berat aspal pen 60. Berdasarkan hasil pengujian diperoleh bahwa lateks kationik (L2) dan lateks pravulkanisasi 4 jam (L3) menghasilkan aspal karet yang lebih baik daripada aspal karet dengan aditif lateks pekat biasa (L1) dan lateks pekat pravulkanisasi 1 jam (L4). Lateks L2 menghasilkan aspal karet dengan titik lembek yang lebih tinggi daripada lateks L3 namun memiliki elastic recovery dan stabilitas penyimpanan yang lebih rendah daripada lateks L3 karena lateks L2 tidak melalui proses pravulkanisasi. Adanya ikatan silang pada lateks pravulkanisasi L3 membuat karet pada campuran aspal karet memiliki elastisitas yang lebih tinggi dan stabilitas penyimpanan yang lebih baik
ANALISIS LOKASI INDUSTRI SERBUK KARET ALAM TERAKTIVASI (SKAT) UNTUK ASPAL KARET
Get PDFUntuk memenuhi kebutuhan aspal yang berkualitas tinggi serta meningkatkan penyerapan karet alam di dalam negeri, pemerintah Indonesia sebagai konsumen utama aspal di Indonesia mulai mencanangkan program pengaspalan yang menggunakan bahan dengan campuran karet padat atau Serbuk Karet Alam Teraktivasi (SKAT) untuk aspal karet. Hal tersebut merupakan peluang bagi perusahaan yang bergerak di bidang aspal. Manajemen perusahaan harus melakukan analisis lokasi pengembangan program ini. Tujuan dari penelitian ini adalah untuk mengetahui lokasi terbaik untuk pendirian pabrik SKAT, dengan metode AHP yang menggunakan tiga kriteria, 24 sub kriteria dan empat  alternatif lokasi. Berdasarkan hasil sintesis terhadap kriteria dan sub kriteria, alternatif lokasi pendirian SKAT secara berurutan sesuai bobot yang dihasilkan adalah Semarang (0,382), Cikampek (0,315), Palembang (0,177) dan yang terakhir adalah Sidoarjo (0,126) dengan rasio konsistensi data 0,01. Keunggulan utama dari lokasi ini adalah letaknya yang strategis dikarenakan memiliki pasar yang prospektif dalam radius 600 Km, dengan panjang jalan nasional 5.611 Km dan jalan daerah sepanjang 109.075 Km. Meskipun jarak dengan sumber bahan baku karet alam tidak sedekat apabila pabrik didirikan di Palembang, serta jarak dengan sumber bahan baku Ground Tyre Rubber (GTR) tidak sedekat apabila pabrik didirikan di Sidoarjo, Semarang memiliki keunggulan lain yaitu harga lahan serta upah tenaga kerja yang lebih murah dibandingkan dengan kota lain
KOMPARASI MORFOLOGI BEBERAPA KOLONI JAMUR AKAR PUTIH (Rigidoporus microporus) DARI PERKEBUNAN KARET DI JAWA TENGAH DAN SUMATERA SELATAN
Get PDFRigidoporus microporus adalah jamur yang menyebabkan penyakit jamur akar putih (JAP) pada tanaman karet. Tingkat keparahan penyakit yang ditimbulkan oleh JAP berbeda antar wilayah. Penelitian ini bertujuan untuk mengetahui komparasi morfologi beberapa koloni jamur akar putih dari perkebunan karet di Jawa Tengah dan Sumatera Selatan. Sampel dikoleksi langsung dari perkebunan Merbuh dan Blimbing di Jawa Tengah dan Balai Penelitian Karet Sembawa di Sumatera Selatan. Penelitian dilakukan pada bulan November 2016-April 2017 di Laboratorium Carotenoid Antioxidant Research Center (CARC) Universitas Kristen Satya Wacana, Salatiga. Hasil yang diperoleh menunjukkan bahwa kecepatan pertumbuhan ke-17 isolat berdasar penambahan diameter koloni hingga mencapai tepi petri bervariasi yaitu 4 hari (MB8), 6 hari (MM6), 7 hari (MK2, MK3, SS1), 8 hari (MK1, MM5, MM7, SS2, SS3), 9 hari (BW1, SS5), 10 hari (MK4, BW4, SS4), 11 hari (BW2), dan 13 hari (BB3). Morfologi koloni dan hifa JAP baik dari Jawa Tengah maupun Sumatera Selatan hampir sama, yakni koloni berbentuk bulat, filamentous, elevasi ada yang rata (flat) dan ada yang sedikit timbul (raised), serta berwarna putih hingga putih gading. Hifa JAP memiliki septa, hialin, bercabang, dan tidak ada clamp connection
ASYMMETRIC PROTOPLAST FUSION BETWEEN PR107 AND REYAN8-79 BY USING PEG
No full textThe genetic improvement of rubber tree using traditional sexual hybridization is a time consuming and laborious task. Somatic hybridization through protoplast fusion is an alternative approach to improve rubber tree, for somatic hybrids had been obtained successfully in many other plant species, and protoplast regeneration systems for several rubber clones had been already established. An attempt was made to perform asymmetric protoplast fusion between two Hevea clones, PR 107 and Reyan 8-79,by using poly ethylene glycol (PEG). Protoplasts derived from embryogenics uspension cells of PR107 were used as donor protoplasts and treated with ultraviolet (UV) irradiation (380 μW/cm2) for 30, 60, 90, 120 and 180 s. Protoplasts derived from embryogenic suspension cells of Reyan 8-79 were used as recipient ones and treated withiodoacetamide (IOA) at concentrations of 1, 2, 3 and 4 mM for 15 min. PEG at 10, 20, 30 and 40% (w/v) were respectively tested to obtain a higher frequency of binary fusion. Results showed that the cell division of donor protoplasts was largely inhibited by UV irradiation for more than 90 s, and that the cell division frequency of recipientprotoplasts was decreased to less than 5% by 3 mM IOA. A maximal binary fusion frequency (about 20%) was obtained when the concentration of PEG was 30%. The donor protoplasts exposed to UVfor 90 s and 120 s were respectively fusedwith the 3 mM IOA-treated recipient protoplastsby using 30% PEG to produce somatic hybrid cells. The fusion products obtained were then transferred onto feeder layer culture.Visible cell colonies from these two fusion combinations were produced 28 and 35 d after feeder layer culture, and their formation frequencies were 146 ± 12 and 23 ± 5 per 105 protoplasts, respectively. They were transferred onto callus inducing medium for multiplication culture for one month, and then transferred onto differentiation medium for somatic embryogenesis. A total of 112 somatic embryos were produced from the cell colonies, but they failed to germinate as they turned brown or vitrified during their further culture. Keywords: Hevea brisiliensis, embryogenic cell suspensions, protoplast fusion, feeder layer culture, somatic embryogenesis, callus, rubbe