Journal of the Rubber Research Institute of Sri Lanka最新文献

{"title":"Annual soil loss assessment of smallholder rubber growing lands in the Kalutara District, Sri Lanka using the RUSLE model in GIS","authors":"L. Liyanaarachchi, J. Sankalpa, P. Ishani, A. Rathnayaka, M. W. H. Gayan, B. Wijesuriya, R. P. Hetiarachchi","doi":"10.4038/jrrisl.v102i1.1913","DOIUrl":"https://doi.org/10.4038/jrrisl.v102i1.1913","url":null,"abstract":"Soil loss resulting from various land management practices in traditional rubber-growing areas of Sri Lanka has been a major issue of concern and one of the factors responsible for declining rubber land productivity. There is no or limited information on the spatial variability of soil loss from rubber lands in Sri Lanka's traditional rubber growing areas. This constraint has had a significant impact on the effective management of soil conservation in rubber-growing lands. This study focuses on assessing the soil loss from the smallholder rubber-growing lands in the Kalutara District using remotely sensed satellite image-based Digital Elevation Model (DEM), rainfall grid data, and prepared soil maps with ground-level surveys by Natural Resource Management Centre (NRMC) Sri Lanka. The factors including rainfall, topography, land area and the crop-specific coefficient for the rubber-growing lands in the study area were analyzed using the Revised Universal Soil Loss Equation (RUSLE) and Geographic Information System (GIS). The study revealed that about 30% of smallholder rubber-growing lands fall under the risk to severe risk categories of soil loss while about 60% of rubber lands are under the low-risk category. About 8,500 ha of smallholder rubber lands can be categorized as risk to severe risk for soil loss whilst about 15,000 ha are under the low-risk category for soil loss. The findings of this study are useful in the implementation of an effective soil conservation management plan and has the potential in applying this methodological approach in other areas of Sri Lanka for various crops.","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89807734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of seed quantity on growth performance of rubber seedling plants and quality of planting material","authors":"W. D. M. N. De Alwis, S. Nakandala, L. Zoysa","doi":"10.4038/jrrisl.v102i1.1909","DOIUrl":"https://doi.org/10.4038/jrrisl.v102i1.1909","url":null,"abstract":"High-quality rubber seeds ensure high seedling performance and successful production of planting materials in the nursery management. An experiment was conducted at Moneragala Sub Station of RRISL in 2020 to investigate the performance of seedling plants raised from different seed quantities to determine the growth and bud-grafting success. Treatments were setup as two times of seed quantity taken and harvested in three rounds (T1-control), three times seed quantity taken and harvested in two rounds (T2), four and five times of seed quantities harvested in one round (T3 and T4). Seed beds of each treatment were arranged according to Randomized Complete Block Design (RCBD) with five replications. Germinated seeds were transferred to the rootstock nursery as soon as the tip of the radical has forced its way through the seed coat. Once the establishment was completed, the growth of seedling plants was evaluated under nursery condition. The seedling plants which were raised from four and five times of seed quantity have significantly increased stem diameter when compared with the control treatment (T1). It was also revealed that dead plant percentage of seedlings raised from control (T1) treatment was high when compared with T3 and T4 treatments. Increasing the number of fresh seeds to four to five times of the required quantity gives more opportunities to select early germinators with high vigor. Therefore, plants that were raised by T3 and T4 treatments have shown a significantly higher bud grafting success (about 80%) as compared to that of T1 and T2 treatments. The overall results revealed that a higher productivity can be achieved with one-time harvested seedlings from four to five times of required seed quantities. However, the seed availability and cost effectiveness of producing planting materials should also be considered in application of suggested method.","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84864410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of symptom-development by different isolates of Phellinus noxius: the causal agent of brown root disease of rubber","authors":"M. K. R. Silva, T. Fernando, R. Wijesundara, C. M. Nanayakkara","doi":"10.4038/jrrisl.v102i1.1910","DOIUrl":"https://doi.org/10.4038/jrrisl.v102i1.1910","url":null,"abstract":"Brown root disease caused by the pathogen Phellinus noxius is an emerging disease condition in the Sri Lankan rubber industry. The possibility of the development of variant pathogen isolates with more pathogenic forms can be considered as one of the factors influencing the increased frequency of its occurrence in the country during the recent past especially in certain parts of the country. The study was conducted to evaluate the variability in symptom development ability of 24 Sri Lankan isolates of Phellinus noxius. A pot trial was carried out by artificially inoculating three months-old rubber seedlings with an inoculated mixture of rice bran and saw dust. Forty seedlings were inoculated with each pathogen isolate, and another forty seedlings were kept as controls without inoculation. Starting after two weeks of inoculation, ten destructive samplings were carried out at two weeks intervals to observe the pathogenicity levels of the different isolates. Based on the below-ground signs and symptoms, a pathogenicity score was given to each uprooted plant. Then those ranks were subjected to Kruskal–Wallis analysis and subsequently to the Wilcoxon rank-sum test. A variation of pathogenicity was observed among the 24 Phellinus noxius isolates. As all the isolates showed a stabilized pathogenicity value at three and half months of the inoculation, a cluster analysis was performed for the mean score values of pathogenicity rank of different isolates at three and half months and the developed dendrogram showed that the test isolates were separated into two main clusters at the similarity level 0.8. It denotes that the studied pathogen population consists of variability and these results can be applied at the development of management strategies.","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75715332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of suitability of sesame oil as an alternative for aromatic processing oil in natural rubber composites","authors":"A. D. Wickramapala, D. Edirisinghe, P. Jayarathna, A. Senevirathna, C. G. Bandara","doi":"10.4038/jrrisl.v102i1.1912","DOIUrl":"https://doi.org/10.4038/jrrisl.v102i1.1912","url":null,"abstract":"Polycyclic aromatic oils, high in aromatic content are used in tyre compounds as processing aids and these have been found to be carcinogenic. Therefore, it is necessary to find processing aids consisting of a low content of aromatics which would help to overcome the problem associated with the use of petroleum-based aromatic oils.\u0000The main aim of this research was to develop carbon black filled natural rubber (NR) composites using environmentally friendly sesame oil as the processing aid. Initially sesame oil was characterized using Fourier Transform Infra-Red analysis. Thereafter, a series of NR based tyre tread compounds was prepared by varying the sesame oil loading from 3-9 phr at 2 phr intervals. Cure characteristics, physico-mechanical and swelling properties of these composites were evaluated and compared with those of the composite prepared with the aromatic processing oil, Dutrex-R (control). Dispersibility of carbon black in all the NR composites was assessed.\u0000Viscosity, processing safety and cure rate of the composite produced with 5 phr sesame oil were higher compared to the control and indicated that the oil behaves as a co-activator in rubber compounds. Hardness, modulus at 100% elongation and abrasion volume loss of the vulcanizates prepared with more than 5 phr sesame oil were lower, whereas tensile strength, elongation at break and resilience were higher than those of the control. Tear strength and compression set of the vulcanizates prepared with 5 phr sesame oil were comparable to those of the control. Further, the former vulcanizate showed a higher and lower swelling indices in toluene and water, respectively compared to the control. Furthermore, the vulcanizates prepared with sesame oil showed better ageing resistance in comparison to the control. Hence, sesame oil could be a suitable alternative for Dutrex-R in tyre tread compounds at 5 phr level.","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89121221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical properties of natural rubber latex foams produced with processed mica waste powder and creamed natural rubber latex","authors":"S. Dananjaya, Y. R. Somarathna, L. Karunanayake, S. Siriwardena","doi":"10.4038/jrrisl.v102i1.1908","DOIUrl":"https://doi.org/10.4038/jrrisl.v102i1.1908","url":null,"abstract":"Incorporation of finely powdered mica waste into natural rubber latex processed into foam rubber, consuming a minimum amount of energy could contribute to progress towards a greener environment. In this study, mica waste generated in the mining industry was finely powdered and incorporated into creamed natural rubber latex which is an alternative form of concentrated latex manufactured using a green process known as the creaming process. Finely powdered processed mica waste (PMW) was added as a filler into latex varying the loading from 0 to 10 pphr at 2 pphr intervals. The latex foam was then converted into a vulcanized natural rubber latex foam (NRLF). Effects of mica loading on certain properties of the foam rubber produced from creamed natural rubber latex were studied. It was found that the density and hardness of the mica powder incorporated foam rubber increased with increasing filler loading. Fourier transformed infrared spectroscopy (FTIR) studies confirmed that no structural changes occurred in natural rubber due to the addition of PMW. The overall results of the study showed the potential of utilization of mica waste and creamed natural rubber latex to manufacture greener natural rubber foam composites in cottage-level foam manufacturing industries.","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77454991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and prioritization of the constraints of rubber farming in Moneragala District","authors":"P. Gunarathne, T. Thennakoon, J. Edirisinghe","doi":"10.4038/jrrisl.v102i1.1914","DOIUrl":"https://doi.org/10.4038/jrrisl.v102i1.1914","url":null,"abstract":"Identification and prioritization of the constraints of rubber farming perceived by rubber smallholders in Moneragala district were the objectives of this study as rubber farming is still being expanded. There were 44 constraints identified by the focus group discussion with 48 Rubber Smallholders (RSs), who were selected from eight rubber-growing DS divisions based on a stratified sampling technique, prior to the questionnaire survey. Identified constraints were listed on the questionnaire. A pre-tested questionnaire survey, a focus group discussion, semi-structured interviews and field observations were used to collect data from 597 rubber smallholders who were selected from eight rubber-growing DS based on stratified sampling technique. The respondents were asked to assign a rank for all constraints. The 44 constraints perceived by rubber smallholders were categorized into following rubber farming activities; 1. Immature up-keeping, 2. Rubber tapping, 3. Manuaring of rubber farming, 4. Rubber processing, 5. Rubber marketing, 6. Extension service related to rubber farming and 7. Thurusaviya rubber societies. Among them, low quality of planting material, lack of knowledge of tapping, lack of knowledge of applying mature fertilizer unavailability of quality acid, low prices for every grade of RSS, lack of training programmes on rubber processing aspects and unsatisfactory input distribution were the highest prioritised constraints address the sustainability of rubber farming in Moneragala by the Henry Garrett Ranking Method. Development of an extension strategic plan in order to transfer the knowledge of the recommended rubber farming practices introduced by the Rubber Research Institute of Sri Lanka to rubber smallholders in Moneragala with the aim of enhancing rubber productivity, restructuring the rubber farming subsidies focused on Intermediate Zone rubber farming, improving the rubber marketing system and strengthening the Thurusaviya rubber societies were identified as strategies to overcome the identified perceived constraints of rubber farming in Moneragala.","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91125915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of blowing agent type and blowing agent loading levels on mechanical and cell morphological properties of dry natural rubber cellular compounds","authors":"W. Sampath, U. A. Weerasinghe, W. P. P. T. Wickramaachchi","doi":"10.4038/jrrisl.v101i0.1902","DOIUrl":"https://doi.org/10.4038/jrrisl.v101i0.1902","url":null,"abstract":"","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85395995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study of different tapping times on latex production in smallholder rubber fields in Moneragala District in Sri Lanka","authors":"P. Seneviratne, S. Nakandala, R. K. Samarasekera, P. K. W. Karunathilake","doi":"10.4038/jrrisl.v101i0.1906","DOIUrl":"https://doi.org/10.4038/jrrisl.v101i0.1906","url":null,"abstract":"","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"50 1-2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78037917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of raw rubber and dynamic properties of RRISL 203 genotype using rubber process analyzer","authors":"A. Attanayake, M. D. Weerasinghe","doi":"10.4038/jrrisl.v101i0.1903","DOIUrl":"https://doi.org/10.4038/jrrisl.v101i0.1903","url":null,"abstract":"","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75754290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of Liquid NR via microwave irradiation as performance improving agent in tyre carcass compounds","authors":"S. D. R. P. Samararathna, S. Siriwardena","doi":"10.4038/jrrisl.v101i0.1905","DOIUrl":"https://doi.org/10.4038/jrrisl.v101i0.1905","url":null,"abstract":"","PeriodicalId":17393,"journal":{"name":"Journal of the Rubber Research Institute of Sri Lanka","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84034800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}