Escherichia coli (E. coli) and other Enterobacteriaceae isolated from fermented products were evaluated for pH, salt tolerance, and multidrug resistance to nine antimicrobial categories, including acetamides, aminoglycosides, β-lactams, cephalosporins, fluoroquinolones, polymyxins, quinolones, sulfonamides, and tetracycline. E. coli was identified in 34% of total fermented samples, followed by Proteus spp. (18%), Providencia spp. (3%), and Citrobacter spp. (3%). Other minor Enterobacteriaceae species detected in 6% of the total samples were Enterobacter aerogenes, Enterobacter cloacae, Ewardsiella tarda, Klebsiella oxytoca, Kluyvera cryocrescens, Morganella moganii, Raoultella planticola, Raoultella terrigena, and Salmonella enterica. Most isolated bacteria can withstand 8% NaCl concentration. However, they were inhibited at 4 pH. Over 50% of the isolated E. coli, Proteus mirabilis, Proteus penneri, and Proteus vulgaris were multidrug-resistant to β-lactams, polypeptides cyclic, sulfonamides, and tetracyclines.
{"title":"Assessing Prevalence and Antibiotic Resistance of <i>Escherichia coli</i> and Other Enterobacteriaceae Isolated from Cambodian Fermented Fish and Vegetables","authors":"Rithy CHRUN, Hasika MITH, Siveng MENG, Sreypov LONG, Pichpunleu BORN, Yasuhiro INATSU","doi":"10.6090/jarq.57.311","DOIUrl":"https://doi.org/10.6090/jarq.57.311","url":null,"abstract":"Escherichia coli (E. coli) and other Enterobacteriaceae isolated from fermented products were evaluated for pH, salt tolerance, and multidrug resistance to nine antimicrobial categories, including acetamides, aminoglycosides, β-lactams, cephalosporins, fluoroquinolones, polymyxins, quinolones, sulfonamides, and tetracycline. E. coli was identified in 34% of total fermented samples, followed by Proteus spp. (18%), Providencia spp. (3%), and Citrobacter spp. (3%). Other minor Enterobacteriaceae species detected in 6% of the total samples were Enterobacter aerogenes, Enterobacter cloacae, Ewardsiella tarda, Klebsiella oxytoca, Kluyvera cryocrescens, Morganella moganii, Raoultella planticola, Raoultella terrigena, and Salmonella enterica. Most isolated bacteria can withstand 8% NaCl concentration. However, they were inhibited at 4 pH. Over 50% of the isolated E. coli, Proteus mirabilis, Proteus penneri, and Proteus vulgaris were multidrug-resistant to β-lactams, polypeptides cyclic, sulfonamides, and tetracyclines.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136199703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We applied data from 407 trees (5-33 years old) from private teak (Tectona grandis) plantations to three typical taper models, including the Goodwin cubic polynomial model comprising hyperbolic and parabolic terms and the Kozak variable-exponent taper model. On the basis of the three models, 18 variants were fitted using nonlinear regression analysis. All models were defined to predict stem diameters overbark using diameter at breast height overbark. A bark thickness equation was prepared to convert overbark diameters to ones excluding the bark. Goodness-of-fit and leave-one-out cross-validation appraisals were used to select the best model. A variant of the Kozak model (Model K8) performed the best across three prediction tests: diameter given height, height given diameter, and log volume given two heights. Taper equation K8, derived from Model K8, provided actual values within the 10% mean error and was sufficiently accurate and precise at the valuable bole part. Teak trees in our study were different in stem form and slender (a high value in slenderness coefficient) compared to those in the state-owned Forest Industry Organization (FIO) teak plantations, and the use of the FIO taper model for slender stems was challenging. Trees in the private plantations generally had thicker barks than those in the FIO plantations. We concluded that equation K8 is recommended for private teak plantations in this study area. These results will contribute to studies on teak taper equations and bark thickness in Thailand.
{"title":"Taper Equations for Evaluating Private Plantation Teak (<i>Tectona grandis</i>) in Thailand","authors":"Iwao NODA, Woraphun HIMMAPAN, Naoyuki FURUYA, Gaku HITSUMA","doi":"10.6090/jarq.57.329","DOIUrl":"https://doi.org/10.6090/jarq.57.329","url":null,"abstract":"We applied data from 407 trees (5-33 years old) from private teak (Tectona grandis) plantations to three typical taper models, including the Goodwin cubic polynomial model comprising hyperbolic and parabolic terms and the Kozak variable-exponent taper model. On the basis of the three models, 18 variants were fitted using nonlinear regression analysis. All models were defined to predict stem diameters overbark using diameter at breast height overbark. A bark thickness equation was prepared to convert overbark diameters to ones excluding the bark. Goodness-of-fit and leave-one-out cross-validation appraisals were used to select the best model. A variant of the Kozak model (Model K8) performed the best across three prediction tests: diameter given height, height given diameter, and log volume given two heights. Taper equation K8, derived from Model K8, provided actual values within the 10% mean error and was sufficiently accurate and precise at the valuable bole part. Teak trees in our study were different in stem form and slender (a high value in slenderness coefficient) compared to those in the state-owned Forest Industry Organization (FIO) teak plantations, and the use of the FIO taper model for slender stems was challenging. Trees in the private plantations generally had thicker barks than those in the FIO plantations. We concluded that equation K8 is recommended for private teak plantations in this study area. These results will contribute to studies on teak taper equations and bark thickness in Thailand.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136199699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aki SAGISAKA, Ritsuko MURAKAMI, Kenji WATANABE, Hiromitsu TANAKA
The brown planthopper (Nilaparvata lugens) is among the most destructive pests of rice in Asia. However, control of this pest is hampered because of the emergence of strains with resistance to standard chemical pesticides. Herein, we investigated the use of RNA interference (RNAi) to knock down genes in the immune system of N. lugens as a possible approach to the control of the pest. We suppressed the expression of the peptidoglycan recognition protein–LC gene and Toll-1 gene by RNAi-mediated knockdown in N. lugens infected with live bacteria. Mortality rates were compared between insects with and without RNAi-mediated gene knockdown. We found that suppression of peptidoglycan recognition protein–LC, which encodes a factor in the immune deficiency pathway, resulted in a significantly increased mortality rate in insects infected with Escherichia coli (gram-negative bacteria) or Micrococcus luteus (gram-positive bacteria). Our results indicate that RNAi knockdown of genes in the immune deficiency pathway will be of value for identifying candidate genes that can be used to control this pest species.
{"title":"Effect of RNA<i>i</i>-mediated Suppression of <i>PGRP-LC</i> Gene Expression on Mortality Rates in Brown Planthoppers (<i>Nilaparvata lugens</i>) Infected with Live Bacteria","authors":"Aki SAGISAKA, Ritsuko MURAKAMI, Kenji WATANABE, Hiromitsu TANAKA","doi":"10.6090/jarq.57.281","DOIUrl":"https://doi.org/10.6090/jarq.57.281","url":null,"abstract":"The brown planthopper (Nilaparvata lugens) is among the most destructive pests of rice in Asia. However, control of this pest is hampered because of the emergence of strains with resistance to standard chemical pesticides. Herein, we investigated the use of RNA interference (RNAi) to knock down genes in the immune system of N. lugens as a possible approach to the control of the pest. We suppressed the expression of the peptidoglycan recognition protein–LC gene and Toll-1 gene by RNAi-mediated knockdown in N. lugens infected with live bacteria. Mortality rates were compared between insects with and without RNAi-mediated gene knockdown. We found that suppression of peptidoglycan recognition protein–LC, which encodes a factor in the immune deficiency pathway, resulted in a significantly increased mortality rate in insects infected with Escherichia coli (gram-negative bacteria) or Micrococcus luteus (gram-positive bacteria). Our results indicate that RNAi knockdown of genes in the immune deficiency pathway will be of value for identifying candidate genes that can be used to control this pest species.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136199700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examined the variation in the gill raker number (GRN: a meristic count) of Pacific bluefin tuna Thunnus orientalis in relation to its early growth using otolith microstructure analysis. A total of 360 age-0 fish (fork length: 102 mm-369 mm) in which the gill raker should have been fully developed were analyzed. The GRN on the upper limb, lower limb, and in total (including one gill raker at the joint of two limbs) ranged from 9-13, 21-26, and 32-40, respectively. GRN was negatively related to early growth, as indicated by the mean otolith increment width. Fish with fewer gill rakers attained better growth during the early life stage than fish with more gill rakers. This relationship was especially evident for growth from 15-19 days after hatching soon before metamorphosis. These results suggest that the early-stage growth of bluefin tuna is an important determinant of morphology. Furthermore, GRN can be an alternative tool for monitoring early growth and may also be related to survival and recruitment success.
{"title":"Relationship between Gill Raker Number and Early Growth of Pacific Bluefin Tuna <i>Thunnus orientalis</i>","authors":"Hiroshige TANAKA, Yosuke TANAKA","doi":"10.6090/jarq.57.345","DOIUrl":"https://doi.org/10.6090/jarq.57.345","url":null,"abstract":"This study examined the variation in the gill raker number (GRN: a meristic count) of Pacific bluefin tuna Thunnus orientalis in relation to its early growth using otolith microstructure analysis. A total of 360 age-0 fish (fork length: 102 mm-369 mm) in which the gill raker should have been fully developed were analyzed. The GRN on the upper limb, lower limb, and in total (including one gill raker at the joint of two limbs) ranged from 9-13, 21-26, and 32-40, respectively. GRN was negatively related to early growth, as indicated by the mean otolith increment width. Fish with fewer gill rakers attained better growth during the early life stage than fish with more gill rakers. This relationship was especially evident for growth from 15-19 days after hatching soon before metamorphosis. These results suggest that the early-stage growth of bluefin tuna is an important determinant of morphology. Furthermore, GRN can be an alternative tool for monitoring early growth and may also be related to survival and recruitment success.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136199701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Waxy barley is considered a good source of dietary fiber and a convenient functional food in Japan; thus, domestic demand is rapidly increasing. However, most of the demand has been met by imports from countries, such as the USA and Canada, as domestic waxy barley production levels have remained low in Japan. To promote the domestic production of waxy barley, the National Agriculture and Food Research Organization has initiated an intensive breeding program to develop and disseminate elite waxy barley cultivars with superior agronomic traits, such as high-yield potential, high disease resistance, and high quality in terms of processing and food. Extensive planting of the newly bred cultivars raised the Japanese domestic self-sufficiency rate of waxy barley from 3 to 49% in 2016 to 2021, respectively.
{"title":"Breeding of Waxy Barley Cultivars in the National Barley Breeding Program of Japan","authors":"Takuji TONOOKA","doi":"10.6090/jarq.57.251","DOIUrl":"https://doi.org/10.6090/jarq.57.251","url":null,"abstract":"Waxy barley is considered a good source of dietary fiber and a convenient functional food in Japan; thus, domestic demand is rapidly increasing. However, most of the demand has been met by imports from countries, such as the USA and Canada, as domestic waxy barley production levels have remained low in Japan. To promote the domestic production of waxy barley, the National Agriculture and Food Research Organization has initiated an intensive breeding program to develop and disseminate elite waxy barley cultivars with superior agronomic traits, such as high-yield potential, high disease resistance, and high quality in terms of processing and food. Extensive planting of the newly bred cultivars raised the Japanese domestic self-sufficiency rate of waxy barley from 3 to 49% in 2016 to 2021, respectively.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136200023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study confirmed a utility of a 10HS sensor, a capacitance sensor, in converted paddy fields to exploit the practical influence volume from our results and the corrected FSC function. Converted paddy fields in Japan are typically used to cultivate lowland rice or upland crops, and many of them have a problem of poor drainage when upland crops are cultivated. One of the major causes of poor drainage is a presence of a hardpan layer due to soil puddling for lowland rice cultivation. To monitor soil moisture above the hardpan layer without the influence of the hardpan layer, we identified the spatial sensitivity around the sensor and determined the applicability of the sensor with the factory-supplied calibration (FSC) function, including under near-saturated conditions. As a result, regarding the spatial sensitivity, the influence volume of the sensor from our result is much smaller than that reported by Cobos (2008), and we suggested that the sensors should be installed at least 1.5 cm above the boundary between the hardpan and plowed layers. Moreover, regarding the calibrations of the sensors, a corrected FSC function that can account for the bulk density was proposed.
{"title":"Spatial Sensitivity and Calibration of 10HS Soil Moisture Sensors in Converted Paddy Fields for Practical Use","authors":"Chika ZUKEMURA, Teruhito MIYAMOTO, Hiroshi OSARI","doi":"10.6090/jarq.57.299","DOIUrl":"https://doi.org/10.6090/jarq.57.299","url":null,"abstract":"This study confirmed a utility of a 10HS sensor, a capacitance sensor, in converted paddy fields to exploit the practical influence volume from our results and the corrected FSC function. Converted paddy fields in Japan are typically used to cultivate lowland rice or upland crops, and many of them have a problem of poor drainage when upland crops are cultivated. One of the major causes of poor drainage is a presence of a hardpan layer due to soil puddling for lowland rice cultivation. To monitor soil moisture above the hardpan layer without the influence of the hardpan layer, we identified the spatial sensitivity around the sensor and determined the applicability of the sensor with the factory-supplied calibration (FSC) function, including under near-saturated conditions. As a result, regarding the spatial sensitivity, the influence volume of the sensor from our result is much smaller than that reported by Cobos (2008), and we suggested that the sensors should be installed at least 1.5 cm above the boundary between the hardpan and plowed layers. Moreover, regarding the calibrations of the sensors, a corrected FSC function that can account for the bulk density was proposed.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136200024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dairy farmers dose their cows continuously with high amount of fat-soluble vitamin supplements to improve reproductive capacity and milk quality. However, these amounts are sometimes detrimental to the health of cows. Farmers require effective methods of vitamin supplementation methods without side effects. Our study aims to ascertain the effects of a single, high-concentration oral dose of vitamin A and E supplements on the reproductive performance of dairy cows. The cows were classified based on when did their first ovulation occur: within the first three weeks postpartum (early responder: ER) or after three weeks postpartum (late responder). This is based on the notion that the first postpartum ovulation is a useful indicator of reproductive function recovery in cows. We tested whether supplementation with vitamin A, E, or both effectively induced ovulation during the early postpartum period. Three out of the eight primiparous cows that were not administered a vitamin supplement and were considered ER. All six primiparous cows that were administered a single supplement mixture containing vitamins A (20,000,000 IU) and E (2,000 mg) three days postpartum were ERs. Additionally, all primiparous cows supplied either vitamin A (n = 4) or E (n = 4) alone were also ERs. All primiparous cows treated with even half the amount of vitamins A and E used in Experiment 1 (10,000,000 IU and 1,000 mg, respectively) were designated ERs. These results strongly suggest that even a single dose of excess vitamin A and E (whether administered jointly or separately) can improve ovarian function in dairy cattle during the early postpartum period.
{"title":"The Role of Single Oral Dose of Excess Vitamin A and/or Vitamin E in Improving Ovarian Function Three Days Post-parturition in Primiparous Dairy Cows","authors":"Mari AOKI","doi":"10.6090/jarq.57.321","DOIUrl":"https://doi.org/10.6090/jarq.57.321","url":null,"abstract":"Dairy farmers dose their cows continuously with high amount of fat-soluble vitamin supplements to improve reproductive capacity and milk quality. However, these amounts are sometimes detrimental to the health of cows. Farmers require effective methods of vitamin supplementation methods without side effects. Our study aims to ascertain the effects of a single, high-concentration oral dose of vitamin A and E supplements on the reproductive performance of dairy cows. The cows were classified based on when did their first ovulation occur: within the first three weeks postpartum (early responder: ER) or after three weeks postpartum (late responder). This is based on the notion that the first postpartum ovulation is a useful indicator of reproductive function recovery in cows. We tested whether supplementation with vitamin A, E, or both effectively induced ovulation during the early postpartum period. Three out of the eight primiparous cows that were not administered a vitamin supplement and were considered ER. All six primiparous cows that were administered a single supplement mixture containing vitamins A (20,000,000 IU) and E (2,000 mg) three days postpartum were ERs. Additionally, all primiparous cows supplied either vitamin A (n = 4) or E (n = 4) alone were also ERs. All primiparous cows treated with even half the amount of vitamins A and E used in Experiment 1 (10,000,000 IU and 1,000 mg, respectively) were designated ERs. These results strongly suggest that even a single dose of excess vitamin A and E (whether administered jointly or separately) can improve ovarian function in dairy cattle during the early postpartum period.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136200022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adaptation to climate change in response to changes in snow cover has led to the development of snow control technology on agricultural fields in Hokkaido. In the control of the soil frost depth and freezing to death of potato tuber leftovers in harvesting during the subsequent cultivation, winter wheat has been an effective countermeasure in crop rotation systems in Hokkaido. We investigated a method used to control soil frost depth by snow compaction (yuki-fumi) to balance between killing potatoes and growing winter wheat. In an experimental test in NARO, we found that snow compaction has a negative effect on wheat growth at a very early stage of the snow cover. Snow compaction does not reduce soil temperatures as much as snow removal, but in potato-to-wheat rotation, it reduced volunteer potatoes by 1/10 because of the shallow position of unharvested potatoes. Snow compaction on wheat can control volunteer potatoes without depending on pesticides and does not adversely affect wheat growth. These environment-friendly agricultural systems have gradually become widespread in eastern Hokkaido.
{"title":"Promotion to Farmers of Snow Compaction (Yuki-Fumi) on Winter Wheat to Control Volunteer Potatoes without Depending on Chemical Materials","authors":"Seiji SHIMODA, Tomoyoshi HIROTA, Masayuki ONODERA","doi":"10.6090/jarq.57.261","DOIUrl":"https://doi.org/10.6090/jarq.57.261","url":null,"abstract":"Adaptation to climate change in response to changes in snow cover has led to the development of snow control technology on agricultural fields in Hokkaido. In the control of the soil frost depth and freezing to death of potato tuber leftovers in harvesting during the subsequent cultivation, winter wheat has been an effective countermeasure in crop rotation systems in Hokkaido. We investigated a method used to control soil frost depth by snow compaction (yuki-fumi) to balance between killing potatoes and growing winter wheat. In an experimental test in NARO, we found that snow compaction has a negative effect on wheat growth at a very early stage of the snow cover. Snow compaction does not reduce soil temperatures as much as snow removal, but in potato-to-wheat rotation, it reduced volunteer potatoes by 1/10 because of the shallow position of unharvested potatoes. Snow compaction on wheat can control volunteer potatoes without depending on pesticides and does not adversely affect wheat growth. These environment-friendly agricultural systems have gradually become widespread in eastern Hokkaido.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136200025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Tigray government in the Federal Democratic Republic of Ethiopia has implemented several water harvesting technologies to improve agriculture in drylands. They constructed 92 micro-dam reservoirs from 1992 to 2012. However, the sedimentation resulting from gully erosion has been settling in more than half of the micro-dam reservoirs. Consequently, it is difficult to provide the required irrigation for the upland fields situated downstream, especially in situations of decreased water availability, caused by the sedimentation over the bottom pipe intake of the irrigational systems/structures. The objectives of the present research are: 1) to verify the conservation of agriculture on farmlands situated at upper slopes for reducing erosion, 2) to estimate the sedimentation rate in micro-dam reservoirs, constructed by the local government, engineers, and residents for recycling the sediments, and 3) to cultivate vegetables on reclaimed farmland by reusing the sediments in micro-dam reservoirs. Thus, this study reports a case study of the water and soil management technology model in a micro-watershed in the Ethiopian highlands.
{"title":"Conservation Technology Model Fit for Farmlands in a Micro-watershed on the Ethiopian Highlands","authors":"Kazuhisa KODA, Gebreyohannes GIRMAY, Tesfay BERIHU","doi":"10.6090/jarq.57.269","DOIUrl":"https://doi.org/10.6090/jarq.57.269","url":null,"abstract":"The Tigray government in the Federal Democratic Republic of Ethiopia has implemented several water harvesting technologies to improve agriculture in drylands. They constructed 92 micro-dam reservoirs from 1992 to 2012. However, the sedimentation resulting from gully erosion has been settling in more than half of the micro-dam reservoirs. Consequently, it is difficult to provide the required irrigation for the upland fields situated downstream, especially in situations of decreased water availability, caused by the sedimentation over the bottom pipe intake of the irrigational systems/structures. The objectives of the present research are: 1) to verify the conservation of agriculture on farmlands situated at upper slopes for reducing erosion, 2) to estimate the sedimentation rate in micro-dam reservoirs, constructed by the local government, engineers, and residents for recycling the sediments, and 3) to cultivate vegetables on reclaimed farmland by reusing the sediments in micro-dam reservoirs. Thus, this study reports a case study of the water and soil management technology model in a micro-watershed in the Ethiopian highlands.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136200021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we investigated the effects of laboratory-scale silage preparation using a plastic bag and incubation on the early-instar larval viability and egg hatchability of fall armyworms (FAWs) inoculated into corn. In experiments performed to evaluate the effects on larval viability, the impacts of vacuum and anaerobic conditions were assessed as factors expected to influence larval viability after silage preparation. In the experiment that evaluated the effects on egg hatchability, the effects of enclosed fresh corn or fermented corn silage were examined. In the experiment that evaluated the effects of vacuum during silage preparation, no viable larvae were detected in anaerobic conditions, regardless of the length of incubation time (24 h or 14 days). In the experiment that confirmed the effects of carbon dioxide (CO2) gas during silage preparation, no viable larvae were noted under enclosed CO2 conditions, regardless of the incubation period (24 h or 14 days). After 3 days of silage preparation, we also found that egg hatchability was 0.05%. These results suggest that forage corn contaminated with FAW has a reduced larval viability rate and egg hatchability in the early stages of silage preparation, suggesting a low chance of FAW spreading from corn silage prepared under airtight conditions.
{"title":"Effects of Forage Corn Silage Preparation on Early-instar Larval Survivability and Egg Hatchability of Fall Armyworms (<i>Spodoptera frugiperda</i>)","authors":"Masayuki HAYASHI, Sachiyo SANADA-MORIMURA, Naoki KATO, Ikuo HATTORI","doi":"10.6090/jarq.57.289","DOIUrl":"https://doi.org/10.6090/jarq.57.289","url":null,"abstract":"In this study, we investigated the effects of laboratory-scale silage preparation using a plastic bag and incubation on the early-instar larval viability and egg hatchability of fall armyworms (FAWs) inoculated into corn. In experiments performed to evaluate the effects on larval viability, the impacts of vacuum and anaerobic conditions were assessed as factors expected to influence larval viability after silage preparation. In the experiment that evaluated the effects on egg hatchability, the effects of enclosed fresh corn or fermented corn silage were examined. In the experiment that evaluated the effects of vacuum during silage preparation, no viable larvae were detected in anaerobic conditions, regardless of the length of incubation time (24 h or 14 days). In the experiment that confirmed the effects of carbon dioxide (CO2) gas during silage preparation, no viable larvae were noted under enclosed CO2 conditions, regardless of the incubation period (24 h or 14 days). After 3 days of silage preparation, we also found that egg hatchability was 0.05%. These results suggest that forage corn contaminated with FAW has a reduced larval viability rate and egg hatchability in the early stages of silage preparation, suggesting a low chance of FAW spreading from corn silage prepared under airtight conditions.","PeriodicalId":14700,"journal":{"name":"Jarq-japan Agricultural Research Quarterly","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136199702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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