R. C. Pereira, B. G. Silva, A. Braccini, M. F. Pelloso, Rafaela T. Costa, Julia M. Pegoraro, Y. M. Borges
This research work aimed to evaluate the physiological quality of soybean seeds subjected to different chemical treatments, before and after seed treatment, throughout conventional storage. A completely randomized design was adopted, with 4 replications, in which the treatments were arranged in a 2 × 7 × 6 factorial scheme (time of treatment (before and after) × industrial seed treatment (IST) × storage period (0, 15, 30, 45, 60 and 90 days). For each IST, the specific volume of slurry was 0, 700, 900, 1400, 900, 1100 and 1600 100 kg-1 of seeds, respectively. A total of 2.5 kg of seeds, cultivar BMX Alvo RR, were used. After being treated, the seeds were placed in kraft paper bags and stored at controlled temperature and humidity in a cold chamber. Their physiological quality was evaluated after each storage period using standard germination test, first germination count, emergence speed index, final emergence in sand substrate, accelerated aging, radicle length, shoot length, and whole seedling length. Their physiological quality was reduced in treatments with higher volumes of slurry. Deleterious effects on vigor were observed with increasing storage period, both before and after IST. After seed treatment, the mean of the analyzed variables was considered higher, compared to the time prior to seed treatment.
{"title":"Physiological Quality of Soybean Seeds Subjected to Industrial Treatment Before and After Storage","authors":"R. C. Pereira, B. G. Silva, A. Braccini, M. F. Pelloso, Rafaela T. Costa, Julia M. Pegoraro, Y. M. Borges","doi":"10.5539/jas.v15n4p37","DOIUrl":"https://doi.org/10.5539/jas.v15n4p37","url":null,"abstract":"This research work aimed to evaluate the physiological quality of soybean seeds subjected to different chemical treatments, before and after seed treatment, throughout conventional storage. A completely randomized design was adopted, with 4 replications, in which the treatments were arranged in a 2 × 7 × 6 factorial scheme (time of treatment (before and after) × industrial seed treatment (IST) × storage period (0, 15, 30, 45, 60 and 90 days). For each IST, the specific volume of slurry was 0, 700, 900, 1400, 900, 1100 and 1600 100 kg-1 of seeds, respectively. A total of 2.5 kg of seeds, cultivar BMX Alvo RR, were used. After being treated, the seeds were placed in kraft paper bags and stored at controlled temperature and humidity in a cold chamber. Their physiological quality was evaluated after each storage period using standard germination test, first germination count, emergence speed index, final emergence in sand substrate, accelerated aging, radicle length, shoot length, and whole seedling length. Their physiological quality was reduced in treatments with higher volumes of slurry. Deleterious effects on vigor were observed with increasing storage period, both before and after IST. After seed treatment, the mean of the analyzed variables was considered higher, compared to the time prior to seed treatment.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88974021","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}
Emily Duenk, N. Soltani, Robert T. Miller, D. Hooker, D. Robinson, P. Sikkema
Weed control efficacy with contact herbicides can depend on weed height at application. Four field experiments were conducted at sites with multiple weed species at different heights to determine the effect of weed height, glufosinate rate, and the addition of ammonium sulfate (AMS) on annual broadleaf weed control in soybean in southwestern Ontario, Canada, during 2021 and 2022. Glufosinate was applied at 300 or 500 g ai ha-1 without or with 6.50 L ha-1 of AMS to 5, 10, and 15 cm tall common lambsquarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.), velvetleaf (Abutilon theophrasti Medik.), and redroot pigweed (Amaranthus retroflexus L.). Glufosinate provided excellent common ragweed control (> 98%) at both rates, without and with AMS, and at all three heights 4 weeks application (WAA). In contrast, glufosinate efficacy declined when applied to common lambsquarters, velvetleaf, and redroot pigweed > 5 cm in height. The addition of AMS to glufosinate improved common lambsquarters control. Increasing the rate of glufosinate to 500 g ai ha-1 and the addition of AMS improved control of velvetleaf and redroot pigweed. The results of this study demonstrate that the effect of glufosinate rate, AMS addition, and weed height at application timing is weed species-specific. In general, glufosinate (300 g ai ha-1) controlled common annual broadleaf weeds if weeds were < 5 cm in height; otherwise, glufosinate needed to be applied at 500 g ai ha-1 with AMS for control of annual broadleaf weeds, especially common lambsquarters, velvetleaf and redroot pigweed.
接触除草剂的除草效果取决于施用时的杂草高度。本研究于2021年和2022年在加拿大安大略省西南部进行了4个不同杂草高度、不同杂草种类的田间试验，研究了杂草高度、草铵膦用量和硫酸铵(AMS)对大豆阔叶杂草的防治效果。分别在5、10和15 cm高的普通羔羊(Chenopodium album L.)、普通豚草(Ambrosia artemisiifolia L.)、棉叶(Abutilon theophrasti Medik.)和重根藜草(Amaranthus retroflexus L.)上施用300或500 g草铵，不施用或添加6.50 L草铵(AMS)。草甘膦在施用4周的三个高度(WAA)下，在不施用和施用AMS的情况下，对豚草的控制效果都很好(> 98%)。草铵膦对身高大于5 cm的普通羔羊草、绒叶草和重根藜草的施用效果下降。在草铵膦中添加AMS改善了对普通羔羊的控制。将草铵膦施用量提高至500 g / hm -1，并添加AMS，可改善对丝叶和重根藜的控制。本研究结果表明，施用时草甘膦用量、AMS添加量和杂草高度的影响是杂草特有的。一般情况下，禾草膦(300 g / ha-1)对禾草高度< 5 cm的常见一年生阔叶杂草有控制作用;对一年生阔叶杂草，特别是常见的羊蹄草、绒叶草和重根藜，则需要在AMS中施用500 g / ha-1草铵膦。
{"title":"Influence of Glufosinate Rate, Ammonium Sulfate, and Weed Height on Annual Broadleaf Weed Control","authors":"Emily Duenk, N. Soltani, Robert T. Miller, D. Hooker, D. Robinson, P. Sikkema","doi":"10.5539/jas.v15n4p7","DOIUrl":"https://doi.org/10.5539/jas.v15n4p7","url":null,"abstract":"Weed control efficacy with contact herbicides can depend on weed height at application. Four field experiments were conducted at sites with multiple weed species at different heights to determine the effect of weed height, glufosinate rate, and the addition of ammonium sulfate (AMS) on annual broadleaf weed control in soybean in southwestern Ontario, Canada, during 2021 and 2022. Glufosinate was applied at 300 or 500 g ai ha-1 without or with 6.50 L ha-1 of AMS to 5, 10, and 15 cm tall common lambsquarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.), velvetleaf (Abutilon theophrasti Medik.), and redroot pigweed (Amaranthus retroflexus L.). Glufosinate provided excellent common ragweed control (> 98%) at both rates, without and with AMS, and at all three heights 4 weeks application (WAA). In contrast, glufosinate efficacy declined when applied to common lambsquarters, velvetleaf, and redroot pigweed > 5 cm in height. The addition of AMS to glufosinate improved common lambsquarters control. Increasing the rate of glufosinate to 500 g ai ha-1 and the addition of AMS improved control of velvetleaf and redroot pigweed. The results of this study demonstrate that the effect of glufosinate rate, AMS addition, and weed height at application timing is weed species-specific. In general, glufosinate (300 g ai ha-1) controlled common annual broadleaf weeds if weeds were < 5 cm in height; otherwise, glufosinate needed to be applied at 500 g ai ha-1 with AMS for control of annual broadleaf weeds, especially common lambsquarters, velvetleaf and redroot pigweed. ","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"59 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90669478","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}
Different methods exist to measure or estimate actual crop evapotranspiration (ETa). However, some methods require a large number of data input or strict field conditions. Remote sensing based ETa algorithms based on extreme thermal pixels (hot and cold) have limitations when required extreme pixels are not present in the acquired thermal infra-red imagery. In addition, satellite overpass frequency and spatial pixel resolution may be a limitation for some agricultural fields and micro-climates. Surface energy balance methods that use surface radiometric temperatures often fail to perform well under drought, limited irrigation, salt affected soils, or under sparse vegetation conditions. One option is to measure or estimate the crop/surface sensible heat flux through the aerodynamic temperature approach, then calculate the available energy and solve the energy balance for latent heat flux. Thus, this study presents different published algorithms that characterize the crop or field surface aerodynamic temperature and then applies them to different conditions for evaluation. Determining spatial ETa continuously has the potential to improve the irrigation water management decision making. The aerodynamic temperature approach was initially developed with good results as a function of surface radiometric temperature, air temperature, crop leaf area index, and wind speed or surface aerodynamic resistance. However, the inclusion of the crop fractional percent cover and of a new resistance term (turbulent-mixing row resistance) greatly improved the estimation of the sensible heat and latent heat fluxes, when evaluated with heat flux data derived from eddy covariance energy balance towers. Results also indicate that the aerodynamic method has transferability potential to different regions, crops, and irrigation methods than the conditions encountered in the method development.
{"title":"Remote Sensing and Aerodynamic Temperature-Based Energy Balance Models to Estimate Crop Evapotranspiration Rates","authors":"J. L. Chávez","doi":"10.5539/jas.v15n4p15","DOIUrl":"https://doi.org/10.5539/jas.v15n4p15","url":null,"abstract":"Different methods exist to measure or estimate actual crop evapotranspiration (ETa). However, some methods require a large number of data input or strict field conditions. Remote sensing based ETa algorithms based on extreme thermal pixels (hot and cold) have limitations when required extreme pixels are not present in the acquired thermal infra-red imagery. In addition, satellite overpass frequency and spatial pixel resolution may be a limitation for some agricultural fields and micro-climates. Surface energy balance methods that use surface radiometric temperatures often fail to perform well under drought, limited irrigation, salt affected soils, or under sparse vegetation conditions. One option is to measure or estimate the crop/surface sensible heat flux through the aerodynamic temperature approach, then calculate the available energy and solve the energy balance for latent heat flux. Thus, this study presents different published algorithms that characterize the crop or field surface aerodynamic temperature and then applies them to different conditions for evaluation. Determining spatial ETa continuously has the potential to improve the irrigation water management decision making. The aerodynamic temperature approach was initially developed with good results as a function of surface radiometric temperature, air temperature, crop leaf area index, and wind speed or surface aerodynamic resistance. However, the inclusion of the crop fractional percent cover and of a new resistance term (turbulent-mixing row resistance) greatly improved the estimation of the sensible heat and latent heat fluxes, when evaluated with heat flux data derived from eddy covariance energy balance towers. Results also indicate that the aerodynamic method has transferability potential to different regions, crops, and irrigation methods than the conditions encountered in the method development.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"72 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74953619","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}
Jeniffer Ribeiro de Oliveira, Thais Santana do Nascimento, André Orlandi Nardoto Júnior, Wanderson Alves Ferreira, Alexandre Morais Borges, I. Gontijo, F. Pires, R. Bonomo, Dalila Bonomo Cosme, V. Lopes, Gabriel Barbosa da Cruz
Mariana Davanzo Miranda, Higor de Oliveira Alves, R. Polanczyk, J. D. Nascimento, Jackson A M de Souza
The complete analysis of the 16S rRNA gene of some non-sporulating bacterial isolates from the soil led us to a reliable taxonomic classification, allowing us to explore its entomopathogenic potential against insect-pest Spodoptera frugiperda. Many studies have shown the rapid development of resistance of S. frugiperda in relation to the methods that have been used in recent decades. Therefore, new research exploring the potential of new soil isolates is important. Thus, a comparative study between the complete and partial taxonomic classification based on 16S rRNA gene was realized as the basis for biological studies. Non-sporulating bacterial isolates were used in lethality bioassays against S. frugiperda larvae to compare bioassays efficacy using Bacillus thuringiensis (Berliner) (Bt) strains and the commercial product Dipel®. The results confirmed the strong resistance of this pest-larvae once it developed until the adulthood phase in all bioassays, applying sporulating or non-sporulating bacteria. Furthermore, an accurate phylogenetic position of the non-sporulating bacterial isolates become possible showing basically three species: Brevibacillus nitrificans, Curtobacterium sp. and Arthrobacter echigonensis. Besides the new biotechnological options for those bacterial isolates, according to the results further research should be done with new bacterial isolates in order to discover its potential to control S. frugiperda, thus assisting Bt in pest control.
{"title":"Taxonomy of Non-sporulating Bacteria Tested in Biological Control Against Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae)","authors":"Mariana Davanzo Miranda, Higor de Oliveira Alves, R. Polanczyk, J. D. Nascimento, Jackson A M de Souza","doi":"10.5539/jas.v15n3p42","DOIUrl":"https://doi.org/10.5539/jas.v15n3p42","url":null,"abstract":"The complete analysis of the 16S rRNA gene of some non-sporulating bacterial isolates from the soil led us to a reliable taxonomic classification, allowing us to explore its entomopathogenic potential against insect-pest Spodoptera frugiperda. Many studies have shown the rapid development of resistance of S. frugiperda in relation to the methods that have been used in recent decades. Therefore, new research exploring the potential of new soil isolates is important. Thus, a comparative study between the complete and partial taxonomic classification based on 16S rRNA gene was realized as the basis for biological studies. Non-sporulating bacterial isolates were used in lethality bioassays against S. frugiperda larvae to compare bioassays efficacy using Bacillus thuringiensis (Berliner) (Bt) strains and the commercial product Dipel®. The results confirmed the strong resistance of this pest-larvae once it developed until the adulthood phase in all bioassays, applying sporulating or non-sporulating bacteria. Furthermore, an accurate phylogenetic position of the non-sporulating bacterial isolates become possible showing basically three species: Brevibacillus nitrificans, Curtobacterium sp. and Arthrobacter echigonensis. Besides the new biotechnological options for those bacterial isolates, according to the results further research should be done with new bacterial isolates in order to discover its potential to control S. frugiperda, thus assisting Bt in pest control.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"20 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80997581","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}
I. A. Amaro-Espejo, M. Castañeda-Chávez, J. Murguía-González, F. Lango-Reynoso, K. P. Bañuelos-Hernández, M. E. Galindo-Tovar, A. M. Fernández-Martínez
Cadmium (Cd) is a toxic element that can be easily absorbed by crops, and can enter through the frequent use of fertilizers in crop areas. The objective of this study was to evaluate the bioaccumulation percentage (BAP) and translocation factor (TF) of Cd in papaya plants exposed to contaminated soils at 50, 100 and 150 mg L-1 and at two concentrations of organic matter: 2% and 10%-MO. Growth variables, chlorophyll and metal concentration were measured after 10 months of cultivation. The results indicated that the greatest growth occurred in soil at 10%-OM in relation to those grown at 2%-OM. Cd bioaccumulation was leaves < stem < root (9 < 22 < 68%) at 50 mg L-1, (7 < 29 < 65%) at 100 mg L-1 and (4 < 34 < 63%) at 150 mg L-1, observing the greatest accumulation in the root. The findings showed that organic matter in soil decreases the availability of metal uptake in the roots. The translocation results were < 1, indicating that the root has the ability to restrict metal transport to the aerial part in plants grown in 10%-OM soil, however, in 2%-OM soil it tends to increase this metal accumulation, suggesting that the application of organic amendments is an alternative to reduce the risk of Cd absorption in agricultural soils.
{"title":"Absorption and Translocation Capacity of Cadmium in Papaya (Carica papaya L.) Plants With Addition of Organic Matter","authors":"I. A. Amaro-Espejo, M. Castañeda-Chávez, J. Murguía-González, F. Lango-Reynoso, K. P. Bañuelos-Hernández, M. E. Galindo-Tovar, A. M. Fernández-Martínez","doi":"10.5539/jas.v15n3p29","DOIUrl":"https://doi.org/10.5539/jas.v15n3p29","url":null,"abstract":"Cadmium (Cd) is a toxic element that can be easily absorbed by crops, and can enter through the frequent use of fertilizers in crop areas. The objective of this study was to evaluate the bioaccumulation percentage (BAP) and translocation factor (TF) of Cd in papaya plants exposed to contaminated soils at 50, 100 and 150 mg L-1 and at two concentrations of organic matter: 2% and 10%-MO. Growth variables, chlorophyll and metal concentration were measured after 10 months of cultivation. The results indicated that the greatest growth occurred in soil at 10%-OM in relation to those grown at 2%-OM. Cd bioaccumulation was leaves < stem < root (9 < 22 < 68%) at 50 mg L-1, (7 < 29 < 65%) at 100 mg L-1 and (4 < 34 < 63%) at 150 mg L-1, observing the greatest accumulation in the root. The findings showed that organic matter in soil decreases the availability of metal uptake in the roots. The translocation results were < 1, indicating that the root has the ability to restrict metal transport to the aerial part in plants grown in 10%-OM soil, however, in 2%-OM soil it tends to increase this metal accumulation, suggesting that the application of organic amendments is an alternative to reduce the risk of Cd absorption in agricultural soils.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"30 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79029787","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}
Taghi Bararpour, Nicholas E. Korres, J. Argenta, T. Tseng
Yellow nutsedge (Cyperus esculentus L.) and Johnsongrass (Sorghum halepense (L.) Pers.) are two of the most difficult weeds to control mostly due to their asexual reproduction. Yellow nutsedge reproduces through underground tubers and Johnsongrass through rhizomes. In addition, Johnsongrass is a problematic weed because of its competitive nature due to its C4 carbon fixation pathway metabolism. It typically grows to 1.8 to 2.5 m tall and can severely reduce yields in corn, cotton, soybeans, and other crops. Two separate field studies were conducted in 2020 at the Delta Research and Extension Center in Stoneville, Mississippi to evaluate the effectiveness of various herbicides on yellow nutsedge and Johnsongrass control in a non-crop scenario. The experiments were conducted as randomized complete block designs with 7 and 11 herbicide treatments for yellow nutsedge and Johnsongrass, respectively. All treatments were replicated three times. Research plots were 4-m wide and 6-m long with 3-m alleys between replications. The 7 yellow nutsedge herbicide treatments consisted of trifloxysulfuron, bentazon, halosulfuron, halosulfuron + thifensulfuron, glyphosate, glufosinate, and paraquat. The 11 Johnsongrass herbicide treatments included clethodim, quizalofop, fluazifop, cyhalofop, fenoxaprop, pinoxaden, glufosinate, glyphosate, clethodim + glyphosate, glufosinate + clethodim, and glufosinate + clethodim + glyphosate. Glyphosate and halosulfuron + thifensulfuron provided only 77 and 72% control of yellow nutsedge by five-weeks after application (WAA). On the other hand, glyphosate, clethodim + glyphosate, glufosinate + clethodim, and glufosinate + clethodim + glyphosate provided 99 to 100% Johnsongrass control 4 WAA. Johnsongrass regrowth evaluation was assessed 3-weeks after the experimental area was mowed. Johnsongrass regrew in every herbicide treatment except for glyphosate which was the only treatment that provided 100% Johnsongrass control with no-regrowth.
{"title":"Evaluation of Herbicides for the Control of Yellow Nutsedge (Cyperus esculentus L.) and Johnsongrass (Sorghum halepense L.) Under Non-Crop Conditions","authors":"Taghi Bararpour, Nicholas E. Korres, J. Argenta, T. Tseng","doi":"10.5539/jas.v15n3p1","DOIUrl":"https://doi.org/10.5539/jas.v15n3p1","url":null,"abstract":"Yellow nutsedge (Cyperus esculentus L.) and Johnsongrass (Sorghum halepense (L.) Pers.) are two of the most difficult weeds to control mostly due to their asexual reproduction. Yellow nutsedge reproduces through underground tubers and Johnsongrass through rhizomes. In addition, Johnsongrass is a problematic weed because of its competitive nature due to its C4 carbon fixation pathway metabolism. It typically grows to 1.8 to 2.5 m tall and can severely reduce yields in corn, cotton, soybeans, and other crops. Two separate field studies were conducted in 2020 at the Delta Research and Extension Center in Stoneville, Mississippi to evaluate the effectiveness of various herbicides on yellow nutsedge and Johnsongrass control in a non-crop scenario. The experiments were conducted as randomized complete block designs with 7 and 11 herbicide treatments for yellow nutsedge and Johnsongrass, respectively. All treatments were replicated three times. Research plots were 4-m wide and 6-m long with 3-m alleys between replications. The 7 yellow nutsedge herbicide treatments consisted of trifloxysulfuron, bentazon, halosulfuron, halosulfuron + thifensulfuron, glyphosate, glufosinate, and paraquat. The 11 Johnsongrass herbicide treatments included clethodim, quizalofop, fluazifop, cyhalofop, fenoxaprop, pinoxaden, glufosinate, glyphosate, clethodim + glyphosate, glufosinate + clethodim, and glufosinate + clethodim + glyphosate. Glyphosate and halosulfuron + thifensulfuron provided only 77 and 72% control of yellow nutsedge by five-weeks after application (WAA). On the other hand, glyphosate, clethodim + glyphosate, glufosinate + clethodim, and glufosinate + clethodim + glyphosate provided 99 to 100% Johnsongrass control 4 WAA. Johnsongrass regrowth evaluation was assessed 3-weeks after the experimental area was mowed. Johnsongrass regrew in every herbicide treatment except for glyphosate which was the only treatment that provided 100% Johnsongrass control with no-regrowth.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"51 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89313603","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}
P. S. Cremonez, J. Matsumoto, Jermaine D. Perier, T. Dunn, D. Pinheiro, P. Neves
The stinkbug Euschistus heros is an important pest of Brazilian agricultural production with increasing importance in the Neotropical region. High reproductive potential and increased risk of resistance to insecticides are determining factors influencing its pest status. This work evaluated the effects of pyriproxyfen on the reproduction and morphological development of the reproductive system of E. heros. Pyriproxyfen was utilized at sublethal concentrations (LC30) in fourth-instar nymphs (N4). Sublethal pyriproxyfen resulted in a reduction in fertility and fecundity of 2 and 12% when only the males were treated, 47 and 53% when only the females were treated, and 32 and 46% when females and males were treated. Basal oocytes were larger and more previtellogenic in newly emerged pyriproxyfen-treated females. The nuclear area of testicular accessory cells shrunk after 10 and 15 days of age in treated insects. Similarly, testicular shape was altered, changing from an ellipsoid to an obpyriform pattern, characterized by hypertrophy of the basal region over time. The apparent area of the organ grew until ten days of age, then shrunk at 15 days of age. In summary, pyriproxyfen treatments disrupted the normal development of N4 of E. heros and diminished the reproductive potential of female and male adults.
{"title":"Morphological and Morphometric Parameters of the Reproductive Organs of Euschistus heros (Hemiptera: Pentatomidae) Treated With a Sublethal Juvenile Hormone Analog","authors":"P. S. Cremonez, J. Matsumoto, Jermaine D. Perier, T. Dunn, D. Pinheiro, P. Neves","doi":"10.5539/jas.v15n3p10","DOIUrl":"https://doi.org/10.5539/jas.v15n3p10","url":null,"abstract":"The stinkbug Euschistus heros is an important pest of Brazilian agricultural production with increasing importance in the Neotropical region. High reproductive potential and increased risk of resistance to insecticides are determining factors influencing its pest status. This work evaluated the effects of pyriproxyfen on the reproduction and morphological development of the reproductive system of E. heros. Pyriproxyfen was utilized at sublethal concentrations (LC30) in fourth-instar nymphs (N4). Sublethal pyriproxyfen resulted in a reduction in fertility and fecundity of 2 and 12% when only the males were treated, 47 and 53% when only the females were treated, and 32 and 46% when females and males were treated. Basal oocytes were larger and more previtellogenic in newly emerged pyriproxyfen-treated females. The nuclear area of testicular accessory cells shrunk after 10 and 15 days of age in treated insects. Similarly, testicular shape was altered, changing from an ellipsoid to an obpyriform pattern, characterized by hypertrophy of the basal region over time. The apparent area of the organ grew until ten days of age, then shrunk at 15 days of age. In summary, pyriproxyfen treatments disrupted the normal development of N4 of E. heros and diminished the reproductive potential of female and male adults.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"68 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87086277","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}
M. Al-Rawahy, W.S. Al-Abri, Alya S. Al-Hinai, H. A. Al-Abri, Siham H. Al-Mahrooqi, Narjis M. Al-Shmali, Zainab T. Al-Khatri, Khalifa S. Al-Subhi
One of the main concerns related to closed systems is the potential spread of root pathogens. With the recirculation of nutrient solutions. Ozone treatment was tested for the efficacy against plant pathogen (Pythium), growth and yield of cucumber crop grown in hydroponic closed system during summer season (June-August) 2022. Two nutrient solution feeding tanks were used one with ozone treatment and other without ozone treatment in randomized complete design (RCD) with four replication. The results showed significant (p < 0.05) differences were observed between the treatments in diseases infections with pythium diseases. No significant (p < 0.05) differences were detected in chlorophyll content, as SPAD values and yield between the two treatment of cucumber statistically. Ozone treated plants produced more yield 4.0 ton/gh.
{"title":"Response of Ozone Treatment on Disease Incidence, Dissolved Oxygen Levels, Growth and Yield of Cucumber Crop Grown in Hydroponics in Cooled Green House. Season: Summer (June-August) at DGALR, Rumais","authors":"M. Al-Rawahy, W.S. Al-Abri, Alya S. Al-Hinai, H. A. Al-Abri, Siham H. Al-Mahrooqi, Narjis M. Al-Shmali, Zainab T. Al-Khatri, Khalifa S. Al-Subhi","doi":"10.5539/jas.v15n3p85","DOIUrl":"https://doi.org/10.5539/jas.v15n3p85","url":null,"abstract":"One of the main concerns related to closed systems is the potential spread of root pathogens. With the recirculation of nutrient solutions. Ozone treatment was tested for the efficacy against plant pathogen (Pythium), growth and yield of cucumber crop grown in hydroponic closed system during summer season (June-August) 2022. Two nutrient solution feeding tanks were used one with ozone treatment and other without ozone treatment in randomized complete design (RCD) with four replication. The results showed significant (p < 0.05) differences were observed between the treatments in diseases infections with pythium diseases. No significant (p < 0.05) differences were detected in chlorophyll content, as SPAD values and yield between the two treatment of cucumber statistically. Ozone treated plants produced more yield 4.0 ton/gh.","PeriodicalId":14884,"journal":{"name":"Journal of Agricultural Science","volume":"39 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88684715","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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