Tropical Agricultural Research and Extension最新文献

{"title":"Effect of finger joining on flexural strength of commonly used timber species in Sri Lanka","authors":"C. Muthumala, S. De Silva, P. Alwis, K. Arunakumara","doi":"10.4038/tare.v21i3-4.5464","DOIUrl":"https://doi.org/10.4038/tare.v21i3-4.5464","url":null,"abstract":"The variation of flexural strength of seven timber species mainly used for furniture industry in Sri Lanka was studied. Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) were measured without finger joint and with finger joint specimens of timber species. Finger joint technique is used to eliminate wood defects which weaken the strength of sawn wood plank and used. This paper gives comparison study of finger jointed and unjointed seven wood species, tested under three point bending test. BS 373: 1957 and BS EN 15497:2014 were used as standards for tests. Vertical finger joint orientation and 13 mm finger joint length were used in this study. The tests for mechanical properties were performed by using a Universal Testing Machine (UTM 100 PC). The parameters were analyzed by using ANOVA and means were separated by Duncan's Multiple Range Test at 0.05 significant levels in SAS. It was found that control (un-jointed solid wood) samples gave the highest flexural strength than finger-jointed specimens and it was also observed that Kumbuk timber species was showed the highest MOE in 13 mm finger-jointed specimens comparing control specimens. The highest flexural strength loss percentage was obtained from Satin species. The MOE of finger-jointed Kumbuk was higher than clear Kumbuk specimens and least strength loss percentage of MOR (46.08 %) was obtained from Mahogany species.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116986390","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":"Academic performance of undergraduates of three new BSc degree programs as affected by gender and, A/L study stream and subject performance","authors":"S. Mudalige, N. Atapattu, N. Dharmadasa","doi":"10.4038/tare.v21i3-4.5468","DOIUrl":"https://doi.org/10.4038/tare.v21i3-4.5468","url":null,"abstract":"Objective of this study was to determine the academic performance of undergraduates of three new BSc degree programs as affected by gender and, A/L stream and subject performance. Semester grade point averages (SGPA) over eight semesters and overall grade point averages (OGPA) of 239 undergraduates who followed BSc in Green Technology (GT), Agricultural Recourse Management and Technology (AT) and Agribusiness Management (AB) were analyzed. Significantly higher percentage of GT (91 %), AB (73 %) and AT (70 %) students had followed Biological Science as their Advanced Level (A/L) stream. The contributions of physics, Chemistry and Biology to the final A/L performance of the students who followed biology stream were 30, 33 and 37 %, respectively. Contrary, among those who had followed Agriculture, the contribution of Chemistry (22 %) was significantly lower than that of Biology stream students (33 %). Subject Agriculture contributed 44 % to the final A/L performance of the students who had followed Agriculture in A/L. Nine percent of the students had dropped the undergraduate programs after taking examinations in one or even three semesters while another 20 % have failed to complete the programme within the four-year period. Repeaters were significantly higher among male students and those who had followed Agriculture in A/L. Among GT, AB and AT students, the percentage of graduates with a class was 78, 65 and 56 %, respectively. Among students having first or second Class Upper Division grades, 87 and 65 %, respectively were females. First semester GPA values were significantly different among the three degree programs. Clear increases in SGPA values were seen from 6 semester in GT program and from 4 semester in AB and AT programs, eventually leading to have statistically similar SGPA values in the 8 semester. In all three programmes, there was a significant linear relationship (r=0.90, p=0.000) between OGPA values and the 4 semester SGPA values. The study concludes that students who follow Agriculture stream in A/L get an advantage over those who follow biology stream, in university admission for the BSc degree programs studied. Academic performance of females and, those who followed biology stream was found to better than males and those who followed Agriculture in the Advanced Level, respectively. Lower degree completion rate within the stipulated time, high drop-out rate, gender inequality in academic performance, and deficiencies of the curriculum of A/L agriculture stream are identified as the critical issues to be addressed.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116061337","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":"Optimization of wheat-sorghum composite flour for the production and enhanced storability of leavened flat bread Naan","authors":"T. Mahendran, G. Hariharan","doi":"10.4038/tare.v21i1-2.5460","DOIUrl":"https://doi.org/10.4038/tare.v21i1-2.5460","url":null,"abstract":"The use of wheat composite flour for commercial production and consumption of leavened flat bread Naan are not yet popularized in Sri Lanka. The present study assessed the effect of optimization of composite flour on the quality of Naan by mixing wheat and sorghum flour at different ratios. Sorghum flours were used 0, 10, 20, 30, 40 and 50 % by weight to replace the wheat flour in the Naan. The formulated Naan were assessed for physicochemical and organoleptic qualities. The moisture, protein, fiber, minerals, loaf weight and loaf volume of the developed Naan were evaluated. The highest moisture content (11.13 %) was recorded in the Naan made with 100 % wheat flour whereas 50 % incorporation resulted in decreased moisture content of 8.11 %. The fiber content increased from 4.78 to 6.04 % with the increment of sorghum flour substitution from 0 to 50 %. The highest mineral content of 2.91 % was recorded from 50 % sorghum flour contained Naan. The highest Naan bread volume of 233cm obtained from 100 % wheat flour, while the mixture containing 50 % sorghum flour resulted in the lower volume of 187cm. As revealed by the sensory evaluation, Naan supplemented with 40 % sorghum flour was well acceptable in terms of colour, taste, texture, aroma and overall acceptability. The mixture of 40 % sorghum flour and 60 % wheat flour was found to be successful for the production of leavened bread Naan with improved physico-chemical and organoleptic qualities within the universally accepted standards. Based on the storage studies, the Naan packed in the low density polyethylene could be frozen stored at -10°C for 90 days without any significant changes in the quality characteristics.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132628839","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":"Twitter™ on aquaculture: understanding the latent information using R","authors":"Tharindu Bandara, K. Radampola","doi":"10.4038/tare.v21i1-2.5459","DOIUrl":"https://doi.org/10.4038/tare.v21i1-2.5459","url":null,"abstract":"","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117187170","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":"Development of coconut sap based non-alcoholic ready to drink beverage","authors":"S. Gunawardhana, H. Hewapathirana, L. Yalegama, P. Lakshman","doi":"10.4038/tare.v21i1-2.5463","DOIUrl":"https://doi.org/10.4038/tare.v21i1-2.5463","url":null,"abstract":"This study was aimed to develop a cost effective non-alcoholic ready to drink beverage using unfermented coconut sap (Meera). Four experiments (each with 3-4 treatments and 3 replicates) were conducted with complete randomized design to find out organoleptically acceptable dilution ratio of sap: water, type of flavor, concentration of flavor and effect on carbonation. Sensory evaluations were conducted for each experiment to select best treatment with 20 number of semi trained panelists. The final products were pasteurized at 950C for 7 minutes and stored 4±20C. Shelf-life evaluation was done in two weeks interval. The dilution ratio of 2:3 (sap: water; v/v) and 0.56% natural lemon flavor were the best combinations for both carbonated and non-carbonated beverages. The initial physicochemical parameters (pH 4.04, Brix 9.0, ash 0.69%, alcohol 0%) were not significantly different for both carbonated and non-carbonated beverages. However, significantly higher (p","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133289976","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 vascular endothelial growth factor 165a on porcine primordial follicle development in vitro: a preliminary study","authors":"D. N. N. Madushanka, W. R. A. S. Mayurawansha, H. Ruwandeepika, M. Magamage","doi":"10.4038/tare.v21i1-2.5462","DOIUrl":"https://doi.org/10.4038/tare.v21i1-2.5462","url":null,"abstract":"Folliculogenesis is a complex process of ovarian follicle growth and development, which is yet to be completely understood. Vascular endothelial growth factor (VEGF) is known for its ability to promote angiogenesis. Among different candidates, VEGF165a is recognized as one of the major factors that determines the degree of vascularisation of the target tissue. This brings up the importance of studying the role of VEGF165a in ovarian follicle activation with special emphasis to ovarian cortex. The objective of current study was to determine the effect of VEGF165a on porcine primordial follicle viability in vitro. This preliminary data was obtained from short-term (72 hours) in vitro culture of porcine ovarian cortical strips under 5% CO2 and 95% O2 under the humidified atmospheric conditions. Cortical strips were treated with 0.1ng/ml VEGF 165a, 1.0ng/ml VEGF 165a, 10.0ng/ml VEGF165a. Parallel to the treatments, a negative control(Tissues were fixed on 10% neutral buffered formalin) and a positive control were conducted.In this study, all the observations suggested that the lower concentrations of VEGF165a has increased the follicle viability among all treated groups (0.1ng/ml,88.02%; 1ng/ml, 67.68%; 10ng/ ml, 25.21%) while higher concentrations implicit higher follicle degeneration (74.79%). In conclusion, the lowest VEGF165a concentration has increased the follicle viability while the highest concentrations implicit increased follicle degeneration in this study.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"239 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121030980","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":"Atrazine residues in Irish potatoe ( Solanum tuberosum L.) varieties from three selected areas in Plateau State, Nigeria","authors":"O. Fayinminnu, MO Odewale, A. Adebayo, K. Thomas, DO Omobusuyi","doi":"10.4038/tare.v20i3-4.5392","DOIUrl":"https://doi.org/10.4038/tare.v20i3-4.5392","url":null,"abstract":"Atrazine is a pre-emergent herbicide used for the control of broad-leaf weeds that has residual activity in the environment. Extensive use of atrazine (strength of 800 g/kg Atrazine 50% WP) in Irish potato production in Plateau State, Nigeria has prompted this study to evaluate the atrazine residue levels in Irish potato varieties in three selected (Mangu, Jos South and Bokkos) areas of Plateau State. A questionnaire-based survey was conducted to determine the types and extent of herbicides used by farmers cultivating Irish potatoes. Samples of four Irish potato varieties: Diamant, Marabel, Christian Lady and Yellow and soils at 0-15cm depth were collected from each of the three Local Government Areas (LGAs). All the samples were subjected to chemical extractions using standard procedures and the extracts were analyzed for atrazine residues using spectrophotometer. Data were analysed using descriptive statistics and ANOVA at p=0.05. Results showed 63.6% of farmers using synthetic herbicides on their farms, while 76.27% used atrazine as their preferred herbicide over paraquat 23.73%. Soil samples from Mangu had significantly highest value of 9.98 mg/kg of atrazine residues and from the Diamant variety with no detection of atrazine in soil samples from other selected LGAs and their respective varieties. The Yellow variety from both Jos South and Bokkos had the highest values of 3.32 mg/kg and 3.13 mg/kg atrazine herbicide residues, while the least value of 1.51 mg/kg was from Diamant variety in Bokkos. However, trazine residue was not detected in Yellow, Marabel and Christian lady varieties from Mangu, Jos South and Bokkos, respectively. This study showed high atrazine residues with concentrations above 0.05 mg/kg and 0.1 mg/kg (US EPA acceptable maximum residue level) in the soil and Irish potato samples, respectively. This atrazine pesticide over time could lead to bioaccumulation in living organisms, food chain and ecosystem.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129339172","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":"Development of an appropriate protocol for micropropagation of Calotropis gigantean (L.) (Wara)","authors":"L. S. Silva, P. D. Perea, S. Senanayake, N. Dahanayake","doi":"10.4038/tare.v20i3-4.5398","DOIUrl":"https://doi.org/10.4038/tare.v20i3-4.5398","url":null,"abstract":"Calotropis gigantea (Wara) is one of the least concerned native plant in Sri Lanka. Because of its high pharmaceutical application and other usage, this species has been over exploited and included in the Red list since year 2012. The present study was carried out to develop a protocol to produce healthy plantlets of C. gigantea. Murashige and Skoog medium (MS) (0, ¼, ½, ¾ and full MS) were tested to select the best medium for in vitro seed germination. To determine the best explant and 6-Benzyl amino purine (BAP) concentration for micro propagation, in vitro shoot tip, stem without node, stem with node, leaf and root were tested with different concentrations of BAP (0, 1 mg/l, 2 mg/l, 3 mg/l, 4 mg/l, 5 mg/l and 6 mg/l) and 0.1 mg/l NAA. Agar and Corn flour were used to gelatinize the medium. To determine the proper maturity level of plantlet, 1, 1 ½, 2, 2 ½ and 3 months old plants were tested. Then regenerated shoots were transferred to different IBA (Indole 3-butyric acid) concentrations (0, 0.5 mg/l, 1 mg/l and 2 mg/l) for rooting. Ten replicates per each treatment were used in every experiment. Data were analyzed according to 2-factor factorial Completely Randomized Design (CRD) using SAS statistical software. The medium with agar (without MS) showed the highest seed germination of 72% while the medium containing full MS showed the lowest seed germination of 34%. Significantly higher number of shoots (2.4) was observed from MS medium with 2 mg/l BAP + 0.1 NAA + Agar within 11days, showing 100% regeneration from stem with node. When corn flour was used instead of agar for the above medium, shoots regeneration was 2.7 within 17 days. One month old explant (stem with node) showed significantly higher number of shoots (2.0) whereas three month old explant showed lowest number of shoots (0.8). The highest number of roots (3.4) was observed from 1mg/l IBA +MS + Agar. However, with corn flour instead of agar, average number of roots was 4.4. Considering these observations, it could be concluded that Agar is suitable as a medium for seed germination. Stem with node is the best explant to produce large number of healthy shoots. The best BAP concentration for shoot regeneration was 2mg/l BAP+0.1mg/l NAA, while 1mg/l IBA was good for rooting. One month old explants were better than matured explants, and corn flour was better compared with agar in increasing the growth and development of C. gigantea.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124446448","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":"Factors influencing youths’ utilization of underutilized indigenous vegetable innovations as a livelihood strategy in southwestern Nigeria","authors":"B. Adisa, O. Ojerinde, Michael Famakinwa","doi":"10.4038/tare.v20i3-4.5396","DOIUrl":"https://doi.org/10.4038/tare.v20i3-4.5396","url":null,"abstract":"Underutilized indigenous vegetables (UIVs) play a highly significant role in food security, employment creation and income generation for the youth in both urban and rural settings in fighting against poverty and hunger. However, certain factors are responsible for youths’ utilization of these innovations in producing these vegetables. The study therefore, focused on factors influencing youths’ utilization of UIV innovation as a sustainable livelihood strategy in Southwestern Nigeria. A multistage stage sampling procedure was used to select the respondents. Data were gathered through structured interview schedule from 155 youths between the age of eighteen to forty years. Data were analyzed using appropriate descriptive statistical tools while factor analysis was used to isolate crucial factors influencing youths’ utilization of UIV innovations. The result showed that the respondents had a mean age of 28.3 years while above half (52.9% and 58.1%) were male and single, respectively. The mean annual income from vegetable production was $ 305.81 with the mean farm size of 0.8 ha. Further results indicated that site selection, marketing and storage were the major UIV innovations utilized by the respondents. Majority (68.4%) utilized UIV innovations at moderate level. Educational, experience, economic benefit, institutional support and community factors were the crucial factors influencing youth utilization of UIVs innovations. Relevant stakeholders should promote utilization of UIV innovations among young farmers as a sustainable livelihood strategy.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127402354","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 production and economic performances of broilers raised under naturally ventilated open-house and tunnel ventilated closed-house systems in Sri Lanka.","authors":"N. Atapattu, L. Abeywickrama, W. Gunawardane, M. Munasinghe","doi":"10.4038/tare.v20i3-4.5393","DOIUrl":"https://doi.org/10.4038/tare.v20i3-4.5393","url":null,"abstract":"The objective of this study was to compare production and economic performances of broilers raised under naturally ven-tilated open house (OH) and tunnel ventilated-closed house (CH) conditions in Sri Lanka. The analysis used production and economic parameters of 130 OH (130 farms) and 88 CH (5 farms) production cycles. Open house farms were select-ed using proportionate random sampling technique while closed houses were purposively selected. The sum of the Per-centages of mortalities and disable birds was significantly higher under OH system compared to that under CH system. The most vulnerable periods for the losses due to mortalities were the first week and from day 29-35 of the growing cycle. The mean length of the growing cycle under OH (38.4 days) was significantly higher than that of CH (34.6 days). OH operators reported a significantly lower number of growing cycles/year (4.4) with a longer clean-out period (44 days) compared to CH (6.9 cycles/year and 18 days, respectively). Production performance indicators such as mortality (3.3%), final live weight (1974 g), feed conversion ratio (1.56), performance efficiency factor (356) of broilers under CH were significantly better than those under OH system (4.5%, 1922 g, 1.94 and 254, respectively). Cost of feeds and day-old-chicks accounted for 74.7 and 23, and 66.6 and 24% of the total variable costs of OH and CH, respectively. Raising of broilers under CH conditions recorded significantly lower total cost (Rs 440), higher net profit (Rs 85.6 bird-1 and unit profitability (Rs 46.8 m-2 day-1) than under OH (Rs 453 and Rs 58.9, Rs 13.2 m-2 day-1, respectively). Production and economic performance indicators and resource utilization efficiencies (temporal and spatial) of broiler production were concluded to be significantly better under CH than OH system. Though production performance parameters of the broiler production, particularly under CH systems were comparable with those of countries having well-developed poultry industries; feed and day-old-chick costs were higher in Sri Lanka.","PeriodicalId":191739,"journal":{"name":"Tropical Agricultural Research and Extension","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132723698","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}