D. Kekulandara, L. Suriyagoda, P. C. G. Bandaranayake, D. Sirisena, N. S. Thilakarathne, W. Samarasinghe
Improvement of nutrient-use efficiency (NUE) in rice is important for increasing productivity. Rice varieties with tolerance to phosphorus (P) deficiency increase the productivity in P-deficient fields. Therefore, the objective of this study was to develop high yielding, P-deficiency tolerant rice varieties to enhance the NUE. High yielding and popular rice varieties (Bg300 and Bg94-1) and known P-deficiency tolerant rice varieties (H4 and At353) were used as female and male parents, respectively, in a crossing program. Single seed descent approach was used for rapid generation advancement. Bg300/At353 and Bg94-1/H4 crosses were advanced from F2 to F6 in planthouse condition under minimum fertigation for restricted growth. In F7 generation, 310 recombinant inbred lines (RIL) in both crosses were space-planted and 40 RILs were selected from each cross. Selected RILs were screened in a hydroponic system at 10 μM P level to select the best lines for P-deficiency tolerance. Multiple plant traits were used for selection and the most promising 20 rice lines were selected as the best performers under P-deficient hydroponic conditions. Marker assisted selection was carried out to confirm the presence of PSTOL1 gene. Selected rice lines were evaluated for agronomic traits and yield parameters. Ten promising rice lines were identified as high yielding lines with accepted agronomic traits.
{"title":"Development of High Yielding Rice Varieties Tolerant to Phosphorus Deficiency","authors":"D. Kekulandara, L. Suriyagoda, P. C. G. Bandaranayake, D. Sirisena, N. S. Thilakarathne, W. Samarasinghe","doi":"10.4038/tar.v35i2.8578","DOIUrl":"https://doi.org/10.4038/tar.v35i2.8578","url":null,"abstract":"Improvement of nutrient-use efficiency (NUE) in rice is important for increasing productivity. Rice varieties with tolerance to phosphorus (P) deficiency increase the productivity in P-deficient fields. Therefore, the objective of this study was to develop high yielding, P-deficiency tolerant rice varieties to enhance the NUE. High yielding and popular rice varieties (Bg300 and Bg94-1) and known P-deficiency tolerant rice varieties (H4 and At353) were used as female and male parents, respectively, in a crossing program. Single seed descent approach was used for rapid generation advancement. Bg300/At353 and Bg94-1/H4 crosses were advanced from F2 to F6 in planthouse condition under minimum fertigation for restricted growth. In F7 generation, 310 recombinant inbred lines (RIL) in both crosses were space-planted and 40 RILs were selected from each cross. Selected RILs were screened in a hydroponic system at 10 μM P level to select the best lines for P-deficiency tolerance. Multiple plant traits were used for selection and the most promising 20 rice lines were selected as the best performers under P-deficient hydroponic conditions. Marker assisted selection was carried out to confirm the presence of PSTOL1 gene. Selected rice lines were evaluated for agronomic traits and yield parameters. Ten promising rice lines were identified as high yielding lines with accepted agronomic traits.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"8 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140764468","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}
I. K. Edirisinghe, K. Thamali, N.H.L.D.L.D. Nanayakkara, D.M.L.N.K. Dissanayake, L.A.R Amarathunge, W.D.P. Weerasinghe, L.D.B. Suriyagoda, S.A.C.N. Perera, D. Jayatilake, K. Thamali, Dissanayake D.M.L.N. Amarathunge
In rice, resistance to bacterial blight (BB) is conveyed by several Xa genes, among which Xa4, Xa21 and Xa38 convey durable resistance. Most Sri Lankan rice germplasm is uncharacterized for the alleles carried at Xa genes. Knowledge on the allele profile of major Xa genes of rice accessions/varieties is essential for making informed decisions in rice breeding programs. In the current study, the allele profiles of 42 Sri Lankan rice accessions/varieties were developed targeting three Xa genes (Xa4, Xa21, and Xa38) using intragenic/linked markers amplifying known resistance/susceptible alleles. According to allele profiles, the rice accessions/varieties were grouped into 11 allele-haplotypes. The varieties, Bg 250, Bg 251 and At 354 carried resistance alleles at Xa4, Xa21, and Xa38 (H1 and H3). Most other accessions/varieties reported either one (Xa4- H8 and Xa38- H10) or two resistance alleles (Xa4 and Xa21- H2; Xa4 and Xa38- H9; Xa21 and Xa38- H11). Three allele-haplotypes were reported with a novel allele at Xa4 (H4, H5, and H6). Ma wee and Kuru wee reported susceptible alleles at all three Xa genes (H7). A significant association (p≤0.05) between the Xa allele-haplotypes and the BB disease response was not observed. To achieve durable BB disease resistance in rice, it is recommended to introgress resistance alleles of the major Xa genes when releasing rice varieties, for which the reported allele profile of Xa4, Xa21 and Xa38 genes in the selected panel of Sri Lankan rice varieties/accessions will be of great importance.
水稻对细菌性枯萎病（BB）的抗性由多个 Xa 基因传递，其中 Xa4、Xa21 和 Xa38 传递持久的抗性。大多数斯里兰卡水稻种质的 Xa 基因所携带的等位基因尚未定性。要在水稻育种计划中做出明智的决策，就必须了解水稻品种主要 Xa 基因的等位基因特征。在本研究中，利用扩增已知抗性/易感等位基因的基因内/连锁标记，以三个 Xa 基因（Xa4、Xa21 和 Xa38）为目标，绘制了 42 个斯里兰卡水稻品种的等位基因图谱。根据等位基因图谱，水稻品种被分为 11 个等位基因单倍型。品种 Bg 250、Bg 251 和 At 354 在 Xa4、Xa21 和 Xa38（H1 和 H3）上带有抗性等位基因。大多数其他登录品种/变种报告了一个（Xa4- H8 和 Xa38-H10）或两个抗性等位基因（Xa4 和 Xa21-H2；Xa4 和 Xa38-H9；Xa21 和 Xa38-H11）。报告了三种等位基因单倍型，其中 Xa4 有一个新等位基因（H4、H5 和 H6）。Ma wee 和 Kuru wee 报告了所有三个 Xa 基因的易感等位基因（H7）。在 Xa 等位基因组型与 BB 病害反应之间没有观察到明显的关联（p≤0.05）。为了实现水稻对 BB 病害的持久抗性，建议在发布水稻品种时导入主要 Xa 基因的抗性等位基因。
{"title":"Allele Profiling of Bacterial Blight Resistance Genes Xa4, Xa38, and Xa21 in Selected Sri Lankan Rice Germplasm","authors":"I. K. Edirisinghe, K. Thamali, N.H.L.D.L.D. Nanayakkara, D.M.L.N.K. Dissanayake, L.A.R Amarathunge, W.D.P. Weerasinghe, L.D.B. Suriyagoda, S.A.C.N. Perera, D. Jayatilake, K. Thamali, Dissanayake D.M.L.N. Amarathunge","doi":"10.4038/tar.v35i2.8745","DOIUrl":"https://doi.org/10.4038/tar.v35i2.8745","url":null,"abstract":"In rice, resistance to bacterial blight (BB) is conveyed by several Xa genes, among which Xa4, Xa21 and Xa38 convey durable resistance. Most Sri Lankan rice germplasm is uncharacterized for the alleles carried at Xa genes. Knowledge on the allele profile of major Xa genes of rice accessions/varieties is essential for making informed decisions in rice breeding programs. In the current study, the allele profiles of 42 Sri Lankan rice accessions/varieties were developed targeting three Xa genes (Xa4, Xa21, and Xa38) using intragenic/linked markers amplifying known resistance/susceptible alleles. According to allele profiles, the rice accessions/varieties were grouped into 11 allele-haplotypes. The varieties, Bg 250, Bg 251 and At 354 carried resistance alleles at Xa4, Xa21, and Xa38 (H1 and H3). Most other accessions/varieties reported either one (Xa4- H8 and Xa38- H10) or two resistance alleles (Xa4 and Xa21- H2; Xa4 and Xa38- H9; Xa21 and Xa38- H11). Three allele-haplotypes were reported with a novel allele at Xa4 (H4, H5, and H6). Ma wee and Kuru wee reported susceptible alleles at all three Xa genes (H7). A significant association (p≤0.05) between the Xa allele-haplotypes and the BB disease response was not observed. To achieve durable BB disease resistance in rice, it is recommended to introgress resistance alleles of the major Xa genes when releasing rice varieties, for which the reported allele profile of Xa4, Xa21 and Xa38 genes in the selected panel of Sri Lankan rice varieties/accessions will be of great importance.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"88 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140765278","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}
This study was aimed to determine the lignocellulosic biomass in different parts of Parthenium hysterophorus and evaluate its antimicrobial activity against selected microbial plant pathogens. Compositional analyses were conducted on live whole plants and their leaves, stems, flowers, and roots. The lignocellulosic biomass components were estimated gravimetrically as a percentage of dry weight, using the standard equation, while reducing sugar was quantified using a glucose standard curve. Significant differences (p < 0.05) in cellulose content were observed among different plant parts, with the highest dry weight percentage in the whole mature plant (48±0.33), followed by the stem (45±0.21), whole young plant (41±0.10), root (21±0.00), leaf (28±0.01), and inflorescence (21±0.14). Additionally, reducing sugar content in mg/mL was significantly higher in the stem (1.94±0.01) and root (1.17±0.00), followed by the mature whole plant (0.95±0.20), leaf-stem mixture (0.93±0.11), inflorescence (0.67±0.02), young whole plant (0.23±0.19), and leaf (0.17±0.01). The stem and root extracts from mature plants inhibited soil-borne plant pathogenic bacteria Pseudomonas sp. and Ralstonia sp. respectively. The leaf and inflorescence extracts of P. hysterophorus showed inhibitory effects only against Pseudomonas sp., not Ralstonia sp. Furthermore, the mature Parthenium plant extract inhibited all tested soil-borne fungi, with significantly higher inhibition percentages observed for Scelerotium sp. (81.93%) and Colletotrichum sp. (45.45%) compared to Fusarium sp. and Pythium sp. Significantly higher cellulose and lignin contents in the whole mature P. hysterophorus plant, along with its antimicrobial activity against major soil-borne plant pathogenic microbes was prominent than the individual plant parts and the young immature plant.
{"title":"Composition and Antimicrobial Activity of Different Plant Parts of Parthenium hysterophorus L.","authors":"K. Niranjan, R. Kapilan, P. N. Yapa","doi":"10.4038/tar.v35i1.8708","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8708","url":null,"abstract":"This study was aimed to determine the lignocellulosic biomass in different parts of Parthenium hysterophorus and evaluate its antimicrobial activity against selected microbial plant pathogens. Compositional analyses were conducted on live whole plants and their leaves, stems, flowers, and roots. The lignocellulosic biomass components were estimated gravimetrically as a percentage of dry weight, using the standard equation, while reducing sugar was quantified using a glucose standard curve. Significant differences (p < 0.05) in cellulose content were observed among different plant parts, with the highest dry weight percentage in the whole mature plant (48±0.33), followed by the stem (45±0.21), whole young plant (41±0.10), root (21±0.00), leaf (28±0.01), and inflorescence (21±0.14). Additionally, reducing sugar content in mg/mL was significantly higher in the stem (1.94±0.01) and root (1.17±0.00), followed by the mature whole plant (0.95±0.20), leaf-stem mixture (0.93±0.11), inflorescence (0.67±0.02), young whole plant (0.23±0.19), and leaf (0.17±0.01). The stem and root extracts from mature plants inhibited soil-borne plant pathogenic bacteria Pseudomonas sp. and Ralstonia sp. respectively. The leaf and inflorescence extracts of P. hysterophorus showed inhibitory effects only against Pseudomonas sp., not Ralstonia sp. Furthermore, the mature Parthenium plant extract inhibited all tested soil-borne fungi, with significantly higher inhibition percentages observed for Scelerotium sp. (81.93%) and Colletotrichum sp. (45.45%) compared to Fusarium sp. and Pythium sp. Significantly higher cellulose and lignin contents in the whole mature P. hysterophorus plant, along with its antimicrobial activity against major soil-borne plant pathogenic microbes was prominent than the individual plant parts and the young immature plant.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"65 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139395545","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}
U. W. L. M. Kumarasiri, U. W. A. Vitharana, T. Ariyawansha, B. Kulasekara
This study investigated the potential of unmanned aerial vehicle (UAV) based multispectral imagery (MI) to predict the leaf nitrogen (N) content of sugarcane (Saccharum officinarum L.). MI of canopy cover of two sugarcane varieties (Co 775 and SL 96 128) applied with different doses of N (0 – 550 kg/ha) were captured at 4½ months after planting. These images were used to calculate 10 different vegetation indices (VIs). Five machine learning (ML) models were tested for their potential to predict leaf N status using the most appropriate VIs. The correlation analysis showed that DVI (Difference Vegetation Index) was the most powerful VI for the prediction of leaf N (r = 0.81), followed by the RVI (Ratio Vegetation Index) and NDVI (Normalized Difference Vegetation Index) (R2= 0.78 and 0.77, respectively). A threshold correlation (r > 0.6) was applied to select predictive variables for ML models and performance was evaluated using a validation data set of leaf N content. Individual variety testing revealed that PLSR (Partial Least Squares Regression) and SVR (Support Vector Regression) models as the best prediction models with the highest Coefficient of determination (R2>0.72) and the lowest Root Mean Square Error values (RMSE<0.11). When both variety data were pooled, RF (Random Forest) demonstrated the highest predictive performance on the validation dataset, with an R2 value of 0.66 with a RMSE value of 0.12. Generally, the prediction accuracy of models was less when data from both varieties were pooled. This study postulated the potential for the fusion of UAV MI and ML approaches to predict leaf N states and the importance of developing varietal-specific prediction models for the sugarcane vegetation.
{"title":"Use of Drone Imagery to Predict Leaf Nitrogen Content of Sugarcane Cultivated Under Organic Fertilizer Application","authors":"U. W. L. M. Kumarasiri, U. W. A. Vitharana, T. Ariyawansha, B. Kulasekara","doi":"10.4038/tar.v35i1.8700","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8700","url":null,"abstract":"This study investigated the potential of unmanned aerial vehicle (UAV) based multispectral imagery (MI) to predict the leaf nitrogen (N) content of sugarcane (Saccharum officinarum L.). MI of canopy cover of two sugarcane varieties (Co 775 and SL 96 128) applied with different doses of N (0 – 550 kg/ha) were captured at 4½ months after planting. These images were used to calculate 10 different vegetation indices (VIs). Five machine learning (ML) models were tested for their potential to predict leaf N status using the most appropriate VIs. The correlation analysis showed that DVI (Difference Vegetation Index) was the most powerful VI for the prediction of leaf N (r = 0.81), followed by the RVI (Ratio Vegetation Index) and NDVI (Normalized Difference Vegetation Index) (R2= 0.78 and 0.77, respectively). A threshold correlation (r > 0.6) was applied to select predictive variables for ML models and performance was evaluated using a validation data set of leaf N content. Individual variety testing revealed that PLSR (Partial Least Squares Regression) and SVR (Support Vector Regression) models as the best prediction models with the highest Coefficient of determination (R2>0.72) and the lowest Root Mean Square Error values (RMSE<0.11). When both variety data were pooled, RF (Random Forest) demonstrated the highest predictive performance on the validation dataset, with an R2 value of 0.66 with a RMSE value of 0.12. Generally, the prediction accuracy of models was less when data from both varieties were pooled. This study postulated the potential for the fusion of UAV MI and ML approaches to predict leaf N states and the importance of developing varietal-specific prediction models for the sugarcane vegetation.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139393107","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}
P. G. N. H. Dharmasiri, P. Ranasinghe, P. T. Jayasooriya, K. Samarakoon
Passiflora foetida (Padagedi) is identified as an underutilized fruit in Sri Lanka, used in traditional medicine for several diseases. The objective of this study was to determine the antioxidant, anti-diabetic, and anti-inflammatory properties of the leaves and fruits of P. foetida. Methanol (100 %) was used to prepare the plant extracts. The antioxidant activity was determined using total phenolic content (TPC), total flavonoid content (TFC), total alkaloid content (TAC), 2,2-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging, ferric reducing antioxidant power (FRAP), and oxygen radical absorption capacity (ORAC) assays. The anti-diabetic effects of plant extracts were determined by using anti-glycation and anti-amylase inhibitory assays. Cell viability was analyzed by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. Based on the findings, the leaf extract of P. foetida showed a higher TPC (21.46±1.56 mg GAE/g of extract), TFC (4.25±0.23 mg QE/g of extract), TAC (4.37±6.50 mg/g of extract), DPPH (10.91±1.29 mg TE/g of extract), ABTS+ (105.80±18.62 mg TE/g of extract), FRAP (11.85±1.45 mg TE/g of extract), and ORAC (46.23±3.58 mg TE/g of extract) compared to its fruit extract. The anti-amylase and anti-glycation activities were high in the leaf extract of P. foetida (30.7% and 77.65 % respectively). The fruit extract of P. foetida had the highest cell viability and nitric oxide (NO) production-inhibition in RAW macrophage (264.7 cells) compared to the fruit extract. It can be concluded that P. foetida has good therapeutic properties, and could be a potential source for pharmaceuticals and nutraceuticals industries.
{"title":"Antioxidant, Anti-Diabetic and Anti-Inflammatory Activities of Passifloara foetida grown in Sri Lanka","authors":"P. G. N. H. Dharmasiri, P. Ranasinghe, P. T. Jayasooriya, K. Samarakoon","doi":"10.4038/tar.v35i1.8701","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8701","url":null,"abstract":"Passiflora foetida (Padagedi) is identified as an underutilized fruit in Sri Lanka, used in traditional medicine for several diseases. The objective of this study was to determine the antioxidant, anti-diabetic, and anti-inflammatory properties of the leaves and fruits of P. foetida. Methanol (100 %) was used to prepare the plant extracts. The antioxidant activity was determined using total phenolic content (TPC), total flavonoid content (TFC), total alkaloid content (TAC), 2,2-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging, ferric reducing antioxidant power (FRAP), and oxygen radical absorption capacity (ORAC) assays. The anti-diabetic effects of plant extracts were determined by using anti-glycation and anti-amylase inhibitory assays. Cell viability was analyzed by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. Based on the findings, the leaf extract of P. foetida showed a higher TPC (21.46±1.56 mg GAE/g of extract), TFC (4.25±0.23 mg QE/g of extract), TAC (4.37±6.50 mg/g of extract), DPPH (10.91±1.29 mg TE/g of extract), ABTS+ (105.80±18.62 mg TE/g of extract), FRAP (11.85±1.45 mg TE/g of extract), and ORAC (46.23±3.58 mg TE/g of extract) compared to its fruit extract. The anti-amylase and anti-glycation activities were high in the leaf extract of P. foetida (30.7% and 77.65 % respectively). The fruit extract of P. foetida had the highest cell viability and nitric oxide (NO) production-inhibition in RAW macrophage (264.7 cells) compared to the fruit extract. It can be concluded that P. foetida has good therapeutic properties, and could be a potential source for pharmaceuticals and nutraceuticals industries.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"14 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139394937","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}
The present study evaluated the usage level of alternative and information communication technology-based advisory and extension approaches, factors affecting the usage behavior, and limitations for implementing such approaches among advisory and extension officials in the tea sector in Sri Lanka during 2020-2022. An online survey was conducted with 72 officials. The majority were male (61%) and the mean age was 41 years. Most (47%) had up to diploma level education with a mean experience of 13 years. The government-imposed restrictions on public gatherings have significantly influenced the advisory and extension in the tea sector during 2020-2022. Respondents mainly connected with growers using mobile phone calls (76.6%) and WhatsApp messages (50%). Lack of communication infrastructure (62.5%), poor ICT knowledge and skills (51.6%), connection issues (57.8%), and inability to observe field conditions (68.8%) are the main barriers encountered by respondents. The main barriers faced by the farmers included lack of communication infrastructure (64.1%), poor ICT knowledge and skills (65.6%), connection issues (68.8%), inability to share quality photos (67.2%), and data cost (60.9%). The Majority of respondents (> 50%) showed positive perceptions towards these approaches and are willing to use them (73.4%) in the future. The results of Spearman’s correlation test showed relationships between the usage frequency of alternative approaches with education (r=0.455, p= 0.000) and age (r= -0.267, p= 0.033). There was a relationship between officials’ perception of alternatives and their usage frequency (r=0.504, p=0.000). In conclusion, the usage of ICT-based methods was higher among young and educated Officials.
{"title":"Alternative and ICT-based Advisory and Extension Approaches in the Tea Sector in Sri Lanka: An Explorative Study","authors":"P. Weththasinghe, U. I. Dissanayeke","doi":"10.4038/tar.v35i1.8703","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8703","url":null,"abstract":"The present study evaluated the usage level of alternative and information communication technology-based advisory and extension approaches, factors affecting the usage behavior, and limitations for implementing such approaches among advisory and extension officials in the tea sector in Sri Lanka during 2020-2022. An online survey was conducted with 72 officials. The majority were male (61%) and the mean age was 41 years. Most (47%) had up to diploma level education with a mean experience of 13 years. The government-imposed restrictions on public gatherings have significantly influenced the advisory and extension in the tea sector during 2020-2022. Respondents mainly connected with growers using mobile phone calls (76.6%) and WhatsApp messages (50%). Lack of communication infrastructure (62.5%), poor ICT knowledge and skills (51.6%), connection issues (57.8%), and inability to observe field conditions (68.8%) are the main barriers encountered by respondents. The main barriers faced by the farmers included lack of communication infrastructure (64.1%), poor ICT knowledge and skills (65.6%), connection issues (68.8%), inability to share quality photos (67.2%), and data cost (60.9%). The Majority of respondents (> 50%) showed positive perceptions towards these approaches and are willing to use them (73.4%) in the future. The results of Spearman’s correlation test showed relationships between the usage frequency of alternative approaches with education (r=0.455, p= 0.000) and age (r= -0.267, p= 0.033). There was a relationship between officials’ perception of alternatives and their usage frequency (r=0.504, p=0.000). In conclusion, the usage of ICT-based methods was higher among young and educated Officials.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"340 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139395153","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}
M. Jayarathna, R. S. Dharmakeerthi, A. D. Igalavithana
Ammonia Volatilization (AV) in rice growing soils is one of the major pathways to lower the use efficiency of added nitrogen (N) fertilizers. Direct broadcasting of urea facilitates AV by increasing the substrate availability. Urea intercalated biochar (BC_U) can be a novel approach that could improve N use efficiency and reduce AV in paddy cultivation. Therefore, a laboratory experiment was conducted to quantify the effect of BC_U pellets on AV losses and N dynamics in a rice growing Entisol. We determined the changes in soil urease activity (UA) and pH buffer capacity (pHBC) after application of BC_U to soil under flooded or saturated conditions. Treatments were zero application of N (control), urea (U) and BC_U pellets added at a rate of 23 mg N kg soil-1. Under saturated conditions, significantly higher NH4+ concentration in soil solution was observed in urea added soils and the highest NO3- was observed in U. Under flooded conditions, a significantly higher NH4+ was in U and NO3- was not affected by urea application. In general, AV losses were very small under the investigated experimental conditions and it varied from 0 to 2.72 % of added urea. Under saturated conditions, AV was significantly (p<0.05) higher in U (2.72 %) and BC_U (1.21 %) than in the Control (0 %). Under flooded conditions, only U showed a significant AV (2.42 %; p<0.05). The pH buffer capacity (11-12 mmols kg-1 pH-1) and urease activity (6.3 - 8.5 μg NH4+-N g-1 hr-1) did not significantly changed (p>0.05) by N treatments. Although there was a small AV loss (<3 %) after N application, it could be further reduced by application of urea as BC_U and/or maintaining a flood water layer for few days after N application.
{"title":"Effects of Biochar Based N Fertilizer Application on Ammonia Volatilization from a Rice Growing Soil: A Laboratory Scale Closed Chamber Study","authors":"M. Jayarathna, R. S. Dharmakeerthi, A. D. Igalavithana","doi":"10.4038/tar.v35i1.8702","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8702","url":null,"abstract":"Ammonia Volatilization (AV) in rice growing soils is one of the major pathways to lower the use efficiency of added nitrogen (N) fertilizers. Direct broadcasting of urea facilitates AV by increasing the substrate availability. Urea intercalated biochar (BC_U) can be a novel approach that could improve N use efficiency and reduce AV in paddy cultivation. Therefore, a laboratory experiment was conducted to quantify the effect of BC_U pellets on AV losses and N dynamics in a rice growing Entisol. We determined the changes in soil urease activity (UA) and pH buffer capacity (pHBC) after application of BC_U to soil under flooded or saturated conditions. Treatments were zero application of N (control), urea (U) and BC_U pellets added at a rate of 23 mg N kg soil-1. Under saturated conditions, significantly higher NH4+ concentration in soil solution was observed in urea added soils and the highest NO3- was observed in U. Under flooded conditions, a significantly higher NH4+ was in U and NO3- was not affected by urea application. In general, AV losses were very small under the investigated experimental conditions and it varied from 0 to 2.72 % of added urea. Under saturated conditions, AV was significantly (p<0.05) higher in U (2.72 %) and BC_U (1.21 %) than in the Control (0 %). Under flooded conditions, only U showed a significant AV (2.42 %; p<0.05). The pH buffer capacity (11-12 mmols kg-1 pH-1) and urease activity (6.3 - 8.5 μg NH4+-N g-1 hr-1) did not significantly changed (p>0.05) by N treatments. Although there was a small AV loss (<3 %) after N application, it could be further reduced by application of urea as BC_U and/or maintaining a flood water layer for few days after N application.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":" 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139392794","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}
G.D.S.P. Rajapaksha, P. Gunathilake, B. Nirooparaj, J. K. Vidanarachchi, B. Jayawardana, M.D.S.T. De Croose, I. Wijesekara, P. C. G. Bandaranayake
Kappaphycus alvarezii Doty (Doty), commonly known as elkhorn sea moss, is a popular seaweed cultivated globally. It is a well-known source of carrageenan, which is a thickening agent used in food and other industries. Even though different morphotypes of K. alvarezii are reported globally, it has been cultivated and marketed as a single genotype. However, such information is important, especially to produce high-value products such as nutraceuticals. Therefore, this study aimed to evaluate differences in microscopic structure, antimicrobial and antioxidant properties, and total phenolic contents of green and brown morphotypes of K. alvarezii cultivated in Jaffna, Sri Lanka. Except for the colour, there was no significant difference in macroscopic parameters. There was no significant difference observed in cross-sections under the light microscope. Antimicrobial properties of ethanol, methanol and water extracts were evaluated by disc diffusion assay against, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Antioxidant properties and total phenolic contents were determined using 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and Folin–Ciocalteau method, respectively. Interestingly, the antibacterial activity, antioxidant properties and total phenolic content of K. alvarezii depend on the morphotype. The green morphotype was rich in total phenolic compounds along with high antibacterial and antioxidant properties. Staphylococcus aureus was the most susceptible bacteria to antimicrobial agents of K. alvarezii and both ethanol and methanol extractions were efficient without significant differences between them in all the assays. The current data suggests better performance of the green morphotype of K. alvarezii as a natural source of antibacterial and antioxidant compounds.
Kappaphycus alvarezii Doty (Doty)，俗称麋角海苔，是一种全球普遍种植的海藻。它是众所周知的卡拉胶来源，卡拉胶是一种用于食品和其他行业的增稠剂。尽管全球都有关于 K. alvarezii 不同形态型的报道，但它一直作为单一基因型进行栽培和销售。然而，这些信息非常重要，尤其是对生产营养保健品等高价值产品而言。因此，本研究旨在评估斯里兰卡贾夫纳栽培的 K. alvarezii 绿色和棕色形态的微观结构、抗菌和抗氧化特性以及总酚含量的差异。除颜色外，宏观参数无显著差异。在光学显微镜下观察横截面也无明显差异。乙醇、甲醇和水提取物的抗菌特性是通过盘扩散法对金黄色葡萄球菌、大肠杆菌和绿脓杆菌进行评估的。抗氧化性和总酚含量分别采用 1，1-二苯基-2-苦基肼（DPPH）自由基清除试验和 Folin-Ciocalteau 法进行测定。有趣的是，K. alvarezii 的抗菌活性、抗氧化性和总酚含量与形态有关。绿色形态富含总酚类化合物，具有较高的抗菌和抗氧化性。金黄色葡萄球菌是对 K. alvarezii 的抗菌剂最易感的细菌，乙醇和甲醇提取物在所有试验中都很有效，两者之间没有显著差异。目前的数据表明，作为抗菌和抗氧化化合物的天然来源，K. alvarezii 的绿色形态具有更好的性能。
{"title":"Comparative Analysis of Green and Brown Morphotypes of Kappaphycus alvarezii Doty (Doty): Morphology, Total Phenol Content, Antioxidant Activity and Antimicrobial Activity","authors":"G.D.S.P. Rajapaksha, P. Gunathilake, B. Nirooparaj, J. K. Vidanarachchi, B. Jayawardana, M.D.S.T. De Croose, I. Wijesekara, P. C. G. Bandaranayake","doi":"10.4038/tar.v35i1.8704","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8704","url":null,"abstract":"Kappaphycus alvarezii Doty (Doty), commonly known as elkhorn sea moss, is a popular seaweed cultivated globally. It is a well-known source of carrageenan, which is a thickening agent used in food and other industries. Even though different morphotypes of K. alvarezii are reported globally, it has been cultivated and marketed as a single genotype. However, such information is important, especially to produce high-value products such as nutraceuticals. Therefore, this study aimed to evaluate differences in microscopic structure, antimicrobial and antioxidant properties, and total phenolic contents of green and brown morphotypes of K. alvarezii cultivated in Jaffna, Sri Lanka. Except for the colour, there was no significant difference in macroscopic parameters. There was no significant difference observed in cross-sections under the light microscope. Antimicrobial properties of ethanol, methanol and water extracts were evaluated by disc diffusion assay against, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Antioxidant properties and total phenolic contents were determined using 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and Folin–Ciocalteau method, respectively. Interestingly, the antibacterial activity, antioxidant properties and total phenolic content of K. alvarezii depend on the morphotype. The green morphotype was rich in total phenolic compounds along with high antibacterial and antioxidant properties. Staphylococcus aureus was the most susceptible bacteria to antimicrobial agents of K. alvarezii and both ethanol and methanol extractions were efficient without significant differences between them in all the assays. The current data suggests better performance of the green morphotype of K. alvarezii as a natural source of antibacterial and antioxidant compounds.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"36 1‐2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139393741","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}
U. L. Karunadhipathi, M. Malaviarachchi, W. M. P. B. Weerasinghe, S. R. G. H. S. M. Jayarathna, K. M. Devindi, M. Mahipala
This study was conducted to investigate the effect of low fertilizer rate and irrigation along with increased plant density on nutritive value of hybrid fodder sorghum cultivated in lowland fallowed paddy fields in dry zone during May to September. Seeds were sown in Yala season and continued as a ratoon crop to inter-monsoonal (Third) season. Four agronomic management packages (AMP1, AMP2, AMP3 and AMP4), which differ in fertilizer application rates, plant spacing, and irrigation intervals were tested with two fodder sorghum varieties (SX-17 and Dairygreen) in a split-plot design. The initial and first ratoon crops were harvested at dough grain stage. High fertilizer rate in combination with short irrigation interval, resulted in high (P<0.05) crude protein content in the initial harvest. AMP2 and AMP4 produced equally high (P<0.05) total dry matter yield (DMY) for SX-17 (24.7 and 20.9 MT/ha, respectively) and Dairygreen (27.7 and 25.7 MT/ha, respectively) varieties. Total digestible organic matter, crude protein and metabolizable energy yields were higher under AMP2 and AMP4 compared to other two packages for both varieties. Nutritive value was high in SX-17 under AMP1 for ratoon crop. In conclusion, AMP4 with plant spacing of 45 x 15 cm, low fertilizer rate (338-47-28 kg/ha, urea-TSP-MOP) and extended irrigation interval, could be recommended for cultivation of hybrid fodder sorghum in lowland paddy fields in the dry zone during Yala season. However, for cultivating SX-17 targeting to produce fodder with high nutritive level, AMP1 with spacing of 45 x 30 cm, high fertilizer rate (400-62-37 kg/ha of urea-TSP-MOP) and frequent irrigation could be recommended.
{"title":"Effect of Change of Agronomic Practices on Nutritive Value of Hybrid Fodder Sorghum Cultivated in Lowland Paddy Fields of the Dry Zone of Sri Lanka","authors":"U. L. Karunadhipathi, M. Malaviarachchi, W. M. P. B. Weerasinghe, S. R. G. H. S. M. Jayarathna, K. M. Devindi, M. Mahipala","doi":"10.4038/tar.v35i1.8705","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8705","url":null,"abstract":"This study was conducted to investigate the effect of low fertilizer rate and irrigation along with increased plant density on nutritive value of hybrid fodder sorghum cultivated in lowland fallowed paddy fields in dry zone during May to September. Seeds were sown in Yala season and continued as a ratoon crop to inter-monsoonal (Third) season. Four agronomic management packages (AMP1, AMP2, AMP3 and AMP4), which differ in fertilizer application rates, plant spacing, and irrigation intervals were tested with two fodder sorghum varieties (SX-17 and Dairygreen) in a split-plot design. The initial and first ratoon crops were harvested at dough grain stage. High fertilizer rate in combination with short irrigation interval, resulted in high (P<0.05) crude protein content in the initial harvest. AMP2 and AMP4 produced equally high (P<0.05) total dry matter yield (DMY) for SX-17 (24.7 and 20.9 MT/ha, respectively) and Dairygreen (27.7 and 25.7 MT/ha, respectively) varieties. Total digestible organic matter, crude protein and metabolizable energy yields were higher under AMP2 and AMP4 compared to other two packages for both varieties. Nutritive value was high in SX-17 under AMP1 for ratoon crop. In conclusion, AMP4 with plant spacing of 45 x 15 cm, low fertilizer rate (338-47-28 kg/ha, urea-TSP-MOP) and extended irrigation interval, could be recommended for cultivation of hybrid fodder sorghum in lowland paddy fields in the dry zone during Yala season. However, for cultivating SX-17 targeting to produce fodder with high nutritive level, AMP1 with spacing of 45 x 30 cm, high fertilizer rate (400-62-37 kg/ha of urea-TSP-MOP) and frequent irrigation could be recommended.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":"57 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139395551","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}
A. M. Tiamiyu, I. O. Olatoye, O. B. Adedeji, R. Okocha
The effect of different concentrations of Chromolaena odorata (Siam weed) supplementation in fish feed on Clarias gariepinus fingerling growth characteristics was examined. Fish were randomly assigned to one of the four experimental groups: 0.0 percent (controls), 0.5 percent, 1.0 percent, and 3.0 percent concentrations of Chromolaena odorata in feed. Fish was fed at 5 percent body weight (g) per day for 70 days. Results showed that fish-fed the treatment diet had no significant effect on weight gain. The final body lengths (cm) of all treated groups were marginally (P > 0.05) different from the control group after 70 days. When the growth parameters were considered, the fish fed the diet containing 1.0 percent Chromolaena odorata had the best growth response (2.4±0.04g) while the fish fed the control diet had the slowest growth (1.2±0.13g). In comparison with the control fish fed the diet containing 1.0 percent Chromolaena odorata had the best feed conversion ratio (FCR), specific growth rate (SGR), and condition factor (K) This study showed that the inclusion of Chromolaena odorata in fish food at 0.5 – 3.0 percent level did not significantly increase the weight and length of catfish.
{"title":"Evaluation of Chromolaena odorata as Growth Promoter in the African Catfish (Clarias gariepinus, Burchell 1822)","authors":"A. M. Tiamiyu, I. O. Olatoye, O. B. Adedeji, R. Okocha","doi":"10.4038/tar.v35i1.8630","DOIUrl":"https://doi.org/10.4038/tar.v35i1.8630","url":null,"abstract":"The effect of different concentrations of Chromolaena odorata (Siam weed) supplementation in fish feed on Clarias gariepinus fingerling growth characteristics was examined. Fish were randomly assigned to one of the four experimental groups: 0.0 percent (controls), 0.5 percent, 1.0 percent, and 3.0 percent concentrations of Chromolaena odorata in feed. Fish was fed at 5 percent body weight (g) per day for 70 days. Results showed that fish-fed the treatment diet had no significant effect on weight gain. The final body lengths (cm) of all treated groups were marginally (P > 0.05) different from the control group after 70 days. When the growth parameters were considered, the fish fed the diet containing 1.0 percent Chromolaena odorata had the best growth response (2.4±0.04g) while the fish fed the control diet had the slowest growth (1.2±0.13g). In comparison with the control fish fed the diet containing 1.0 percent Chromolaena odorata had the best feed conversion ratio (FCR), specific growth rate (SGR), and condition factor (K) This study showed that the inclusion of Chromolaena odorata in fish food at 0.5 – 3.0 percent level did not significantly increase the weight and length of catfish.","PeriodicalId":23313,"journal":{"name":"Tropical agricultural research","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139393109","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}
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