Puslit Penelitian Karet E-Journal System Portal
Not a member yet
531 research outputs found
Sort by
A LOW FREQUENCY HARVESTING SYSTEM EXCLUSIVELY FOR SMALLHOLDER RUBBER GROWERS BEING EMPLOYED OFF-FARM
No full textA system in which rubber trees could be harvested on weekly basis was developed enabling smallholders in Sri Lanka (having less than 1 ha of rubber) to use own labour for rubber tapping during weekend holidays. Latex harvesting is undertaken here on two consecutive days per week with the application of 2% ethephon biweekly (S/2 d1 2d7 2% ET every two weeks). This system provides a comparable yield to what given by the traditional S/2 d2 system. As per the biochemical and physiological parameters of latex, no indication on stress factors was evident. When compared to traditional S/2 d2 harvesting, the new system was able to reduce the cost of production by LKR 135/= per kg of rubber and thereby increasing the profit margin by LKR 274,448/= per hectare per year due to the use of own labour in latex harvesting. Just one day tapping per week is also possible with the application ethephon 5% monthly, should 5% yield decline be acceptable in lieu of saving the tapping cost incurred in hired labour.Keywords : ethephon, Hevea, leisure, socioeconomics, weekend harvestin
CHARACTERIZATION OF PESTALOTIOPSIS MICROSPORA, CAUSAL AGENT OF LEAF BLIGHT ON RUBBER (HEVEA BRASILIENSIS) IN CAMEROON
No full textRubber tree (Hevea brasiliensis) is the only commercial source of natural rubber in Cameroon. Its cultivation can be severely limited by diseases A leaf blight disease was observed on rubber trees affecting 80% of plants in smallholder's fields in South West Cameroon. Symptomatic leaf samples were collected from infected plants and pathogens isolated from them on agar media. Single spore isolates from resulting colonies were identified as Pestalotiopsis microspora based on cultural and morphological characterisation. Culture media, incubation temperature and pH affected mycelial growth of P. microspora. Its inoculation on detached leaflets also revealed the pathogenic capacity of this fungus; re-isolation based on its symptoms confirmed Koch’s postulates. Morphological identification was confirmed by molecular sequence analysis of the Internal Transcribed Spacer (ITS) region 1 and 2 including 5.8S rDNA (ITS-5.8S-ITS2).  The effects of some fungicides were tested in vitro on P. microspora mycelial growth. Banko plus fungicide (Chlorothalonil 550g/l + Carbendazim 100g/l), Penncoz (Mancozeb 800g/kg) and Metalm 72 WP (Cuprous oxide 600g/kg + Metalaxyl 120g/kg) tested at different concentrations (100%, 75%, 50% and 25%) revealed inhibitory activity against P. microspora in vitro. Among these fungicides, a marked efficiency of chlorothalonil 550g/l was observed, though the inhibition of mycelial growth was more effective with Cuprous oxide 600g/kg + Metalaxyl 120g/kg at rates: 100%, 75% and 50% only. This study revealed that P. microspora is the causative agent of new leaf blight on rubber in the South West Region of Cameroon. This is the first report of leaf blight caused by P. microspora on rubber in Cameroon. Keywords: Pestalotiopsis microspora, Internal transcribed spacer, pathogenicity, rubber, leaf  blight
PATHOGENICITY TEST OF LASIODIPLODIA THEOBROMAE ISOLATES FROM SIX HOST PLANTS ON RUBBER AND THEIR PHYLOGENY ANALYSIS
No full textStem cankers caused by the fungus Lasiodiplodia theobromae on rubber plant (Hevea brasiliensis Muel Arg.) is a new disease and has not yet been reported in Indonesia. L. theobromae is a polyfag fungus and has a wide host range. The fungus is able to live as a saprophyte on leaves, dead wood, plant debris, and can also be parasitic on some plants. The variability of disease symptoms and host range of the fungus indicate the probability that this species has several strains. The strains have different virulence levels and symptoms on each host. There has been no information whether a strain of the fungus L. theobromae from any particular host plant can infect rubber plant. This study was carried out to determine the symptoms caused by the fungus L. theobramae from several hosts on rubber plants and phylogenetic analysis of L. theobramae from several host plants. The results showed that the six isolates inoculated on rubber plants i.e isolates from mango, banana, guava, avocado, rubber and citrus produced the disease symptoms and there are no differences in symptoms except for the isolate from rubber, where the disease severity appeared to be higher and it caused the death of the inoculated branch.Keyword: Lasiodiplodia theobromae, Hevea brasiliensis, canker disease, phylogeny analysis, pathogenicit
L-QUEBRACHITOL FROM HEVEA LATEX: CHALLENGES TO ITS COMMERCIALIZATION
No full textThe main challenges to the commercialization of L-Quebrachitol derived from Hevea latex are discussed. It is viewed that the high recovery cost of L-Quebrachitol and the unfavorable organic synthesis steps needed when using L-Quebrachitol as the starting material in the production of active pharmaceutical ingredients are the main obstacles to its commercialization. An alternative approach is proposed involving the bio-transformation of L-Quebrachitol which requires further research
POTENCY AND MANAGEMENT OF ORGANIC MATERIALS IN RUBBER PLANTATION IN INDONESIA
No full textPlant nutrient management, especially organic materials is one of the interesting topics to be studied more deeply in rubber tree plantation. The price of rubber tends to decrease every year. It encourages the planters to utilize organic materials as fertilizer substitute agent. Organic materials have a function to improve the physical, chemical, and biological characteristic of soil.Organic materials, besides from the plantation (in situ) such as weeds, cover crops, and twigs, but it’s also be sourced from outside the plantation (ex situ) such as compost from oil palm industry. Litter potency from legume cover crop of Mucuna bracteata (Mb) in immature rubber plant area as soil organic material is big enough that is 2–7 ton/ha/year or 2,5-7 times higher than conventional cover crop. Furthermore, potency of nutrient returns to soil from Mb biomass amount 250,98 kg/ha N; 9,08 kg/ha P2O5; 72,5 kg/ha K2O; and 11,95 kg/ha MgO. The existence of cover crop in immature rubber plant interrows also affect to uniformity of rubber plant, the number of mature rubber, and bark thickness better than conventional cover crop.Waste of oil palm industry such as empty fruit bunches and oil palm frond (OPF) also very potential to be used as organic material source to rubber plant. The number of rubber fine roots which is sized < 1 mm in diameter increased up to twice compared with a rubber plant without oil palm empty fruit bunches application. CEC value, C-organic and N, P, K, Ca, Mg content were reported also increased significantly. OPF is agricultural waste that have high lignin and cellulose and with an appropriate composting management become potential to produce manure compost on day 75. In Immature rubber plant, dose of 20 ton/ha increased soil porosity and decreased in bulk density compared plant without compost of OPF application. The treatment of 20 % compost + 80 % subsoil significantly increased the root dry weight of rubber plant seedling and also increased pH, CEC, C-Organic, P, K, Ca, and Mg soil content. Application of organic matter in plantation can be combined with “rorak†(small blocked ditches). This condition causes the water plant needs can be fulfilled in dry season hence fertilizer application will be more efficient and nutrient uptake better.Keywords: Hevea brasiliensis, organic matter, nutrient, Mucuna bracteata, compos
PHYSIOLOGICAL CHARACTERS AND PRODUCTION TOWARD TAPPING PANEL DRYNESS OF PB 260
No full textTapping panel dryness (TPD) is one of the most important issues in the cultivation of rubber trees. In fact, TPD starts gradually so that the planters are not aware about the incidence in the field. TPD is caused by abiotic, biotic and management exploitation. One of the factors is tapping and stimulation intensity. The purpose of this study was to study the effect of tapping frequency on the occurrence of TPD, production pattern, physiological characters, growth and grouping of main factors related to TPD. The experiment was carried out at Sembawa Research Station in 2010 and 2012, used PB 260 clone planted in 2004 with tapping frequency S/2 d1 6d/7, S/2 d2 6d/7, and S/2 d4 6d/7. Data analysis was done with principle component analysis. The results showed that daily tapping (d1) induced TPD on 5 months after opening and increased to 75% at 24 months after opening. The signal toward TPD was “overactive†metabolism where the latex yield and Pi increased significantly whereas sucrose content decreased. After TPD, yield was lower than on the healthy trees, and the girth increment was higher. Sucrose and Pi parameters can be used as an early warning signal of TPD occurrence. Keywords : PB 260, TPD, sucrose, Pi, thiol, TSC, yield, girth
RISE OF THE GREEN ECONOMY: IMPLICATIONS ON THE NR INDUSTRY
No full textThere is no denying that the green economy is already upon us. And many are convinced that the phenomenon is unstoppable. Experts are unanimous on the fact that the world is destined to be ruled more and more by a growing preference for green products and services. Increasingly, customers worldwide are showing their detestment of products and services which pose serious threats to the environment and the natural ecosystem related to it. It is easy to understand why. Despite recent adverse rhetoric by the new US administration which dispute the phenomenon of global warming and the consequent climate change, most other countries are stuck to the belief that climate change is real. The evidences presented by world climate scientists are very convincing. Rising global temperatures, the melting of the arctic ice, rising sea water levels and frequent extreme weather conditions are all documented proofs that the global climate is undergoing drastic change. A change which, unless arrested or reversed, can spell disaster for the world community. The green economy is not just about climate change. Another important megatrend driving the rise of the green economy is the growing depletion of key resources. These include energy, water and materials as a result of the burgeoning world population. The world population which has already exceeded 7 billion is inching towards the 8 billion mark in a matter of years. At the current rate of consumption, the demand for such resources is not going to be sustainable. Though the preference for renewable materials will rise, the capacity to generate them will be limited by land. And the opening up of new agricultural land is also strongly opposed by the need to preserve and conserve the environmentally sensitive areas of the forests. There is no doubt that the rise of the green economy bears serious implications on all industries, NR included. Their production systems will have to change. Their consumption patterns will also have to change. Undoubtedly the NR industry will face both threats and challenges. But there will also be opportunities. If the NR industry is carefully planned, with the right strategies, it is not impossible for the industry to neutralise such challenges and capture the opportunities. This is where investment in R&D and more intelligent production systems is key. This paper discusses the factors driving the rise in the global green economy and the positive and negative implications on the world NR industry
GENETIC DISSECTION OF DISEASE RESISTANCE TRAIT IN RUBBER TREE (HEVEA BRASILIENSIS) THROUGH QTL MAPPING
No full textAbnormal leaf fall disease caused by Phytophthora meadii and Corynespora leaf disease caused by Corynespora cassiicola are the two major diseases of rubber (Hevea brasiliensis) in India causing significant loss to rubber production. Identifying genes conferring tolerance to these fungal diseases is highly desired for resistance breeding in rubber. Resistance traits are mainly quantitative in nature and are determined by many genes, which are described as quantitative trait loci (QTL). Genetic markers have made it possible to detect QTLs that are significantly associated with traits. Construction of a linkage map, densely populated with molecular markers, is essential for dissection of QTLs for disease resistance trait. An interspecific cross between H. brasiliensis (clone RRII 105) and H. benthamiana (clone F4542) with varying levels of disease resistance was made and a progeny population was raised for construction of a linkage map. RRII 105 is a commercially cultivated high yielding clone with moderate level of susceptibility to P. meadii and high level of susceptibility to C. cassiicola. F4542 is a low yielder with high level of tolerance to both P. meadii and C. cassiicola. Genotyping of the mapping population comprising 86 progenies along with two parents was carried out using co-dominant SNP markers and dominant silico DArT markers derived from DArT sequencing (DArTseqTM). A linkage map with the DArTseq data was constructed using DArT PL’s OCD MAPPING program. Kosambi mapping function was used to estimate genetic distances. A linkage map was produced for each parent by combining the relevant silico DArT and SNP markers. A consensus map was created using 24004 markers, which assembled into 18 linkage groups, thus reflecting the haploid chromosome number of Hevea (n = 18). An average of 1334 markers per chromosome was estimated with an average inter marker distance of 0.15 cM and total map distance was calculated as 3709 cM. Phenotyping for disease resistance to both P. meadii and C. cassiicola infections was carried out for the parents and 86 progeny population. Zoospores from a virulent isolate of P. meadii was used for in vitro challenge inoculation on leaves of each individual followed by measuring the lesion size periodically from 72-120 hours to assess disease reaction. Toxin-based screening methodology was employed to check for disease resistance to C. cassiicola. Wilting intensity on the tender leaves due to the effect of toxin was assessed 24 hours following the toxin treatment. Assessment for disease response clearly discriminated progenies with varying levels of resistance reactions to both P. meadii and C. cassiicola. Progenies with extreme levels of tolerance and susceptibility were identified along with the majority of the population showing moderate level of resistance/ susceptibility. Frequency distribution of disease resistance among the progeny was continuous indicating their quantitative nature of inheritance. In order to identify QTL markers conferring resistance to these fungal diseases, genotypic and phenotypic data for disease resistance from the progeny population were merged and analyzed. Six QTL markers for Phytophthora disease resistance [five mapped in linkage group (LG) 9 and one in LG 15] and seven for Corynespora disease resistance (one each mapped in LG 6, 11, 13 and two each in LG 8 and 16) were identified at an adjusted P value cut off 0.001 and a LOD threshold score of 3. The identified potential QTL markers need to be validated prior to their use in early selection of hybrid clones for tolerance to these fungal diseases
BIO-C: A NEW BIOFUNGICIDE TO CONTROL PINK DISEASE (CORTICIUM SALMONICOLOR) ON RUBBER PLANTS
No full textBIO-C is a biofungicide to control pink disease (Corticium salmonicolor B. et Br.) on rubber plant (Hevea brasiliensis). Pink disease becomes one of the important diseases especially in the areas with high humidity condition. It attacks rubber plants in high and moderate rainfall locations with higher plant density or canopy. The parts attacked are the branching regions and the stem close to the ground. The symptoms of pink disease are characterized by the presence of white mycelium which is like spider’s web, followed by pink bark necrosis. And release of latex that turn black on the surface of the cracked infected bark. The main branch may break causing death of the plant. The recommended fungicides for control of this disease is not available in the market, BIO-C is a cheap and eco-friendly fungicide tried for control of pink disease. It contains an antagonistic bacteria (Pseudomonas sp.) with 55 x 109 CFU and other ingredients. The ready-mixformulation of BIO-C facilitates its application by simply and applying directly to the affected parts. The application interval is once a week for 4 times. The dose of one time application is about 50 cc / plant depending on the extent of the pink disease attack. Efficacy tests have been conducted in laboratory and field scale since 2008. The results obtained in 2008-2009 indicated its effectiveness with a recovery of 76.93%. On a larger field scale trial in 2011 and 2012 the effectiveness of this biofungicide were 80.49% and 89.2% respectively. In terms of economic value, BIO-C is twice cheaper than chemical fungicides.Keywords : BIO-C, Hevea brasiliensis, pink disease
KELAYAKAN FINANSIAL TANAMAN KAYU UNTUK MEMANFAATKAN LAHAN YANG KURANG SESUAI UNTUK KARET
Get PDFKondisi lahan salah satu perkebunan karet di Jawa Tengah memiliki kelas kesesuaian lahan yang bervariasi untuk tanaman karet. Terdapat 25,2% yang termasuk dalam kelas kurang sesuai dan tidak sesuai. Lahan dengan kondisi tersebut akan optimal jika ditanami komoditas yang sesuai. Komoditas alternatif yang dinilai prospektif dikembangkan adalah tanaman kayu seperti sengon, jabon dan akasia. Penelitian ini bertujuan untuk memperoleh gambaran tentang kelayakan secara finansial pengusahaan tanaman kayu sebagai komoditas alternatif untuk mengoptimalkan lahan perkebunan berbasis karet. Penelitian ini dilakukan di beberapa perkebunan karet di Provinsi Jawa Tengah pada bulan Februari - Desember 2016. Metode penelitian yang digunakan adalah metode survei dengan cara memilih sampel secara purposive pada 12 kebun berbasis tanaman karet. Data penelitian dianalisis dengan menggunakan metode penelitian deskriptif dan kuantitatif. Hasil penelitian menunjukkan bahwa ketiga jenis tanaman kayu (sengon, jabon dan akasia) secara finansial layak untuk dikembangkan dengan nilai net present value  sebesar Rp 6 juta - Rp 25 juta, internal rate of return  21% - 34%, gross benefit cost ratio 1,4 - 2,3, dan revenue cost ratio  2,2 - 4,5. Hasil uji sensitivitas menunjukkan bahwa ketiga tanaman tidak sensitif terhadap perubahan biaya dan harga jual. Pada saat tekanan ekonomi biaya naik 10% - 30% dan harga turun 10% - 30%, baik secara terpisah maupun bersama-sama, diperoleh nilai R/C > 1. Dengan demikian, sengon, jabon dan akasia merupakan tanaman alternatif yang prospektif untuk optimalisasi pemanfaatan lahan perkebunan berbasis karet