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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

The use of adjuvants to improve fungicide spray deposition on grapevine foliage

Van Zyl, Sybrand Abraham 03 1900 (has links)
Thesis (MScAgric (Plant Pathology))--Stellenbosch University, 2009. / ENGLISH ABSTRACT: Sufficient fungicide deposition on the target site is an essential requirement for effective chemical management of fruit- and foliar diseases such as grey mould of grapevines. Control failure is often attributed to insufficient quantitative deposition on susceptible grapevine tissue. However, in high disease pressure situations control failure might also be attributed to poor qualitative deposition. The primary objective of spray technology is to optimise deposition, of which the plant surface is a critical component in the spray application process, specifically in the retention of spray droplets. Adjuvant technology is reported to improve the wettability and spread of droplets by surface-acting-agents on the target surface and thereby improve deposition and retention of the fungicide active ingredient. However, this relatively new spray technology on viticulture and horticultural crops, and possible effects of adjuvants on epicuticular wax affecting plant disease development, needs to be investigated. Moreover, the development of useful prescriptions for adjuvants by determining water volumes and adjuvant dosages is required for different pesticide tank mixes. The aims of this study were, firstly to determine the effect of selected adjuvants on quantitative and qualitative spray deposition on grapevine leaves and subsequent biological efficacy of a fungicide, and secondly to evaluate selected adjuvants under field conditions and determine the effects of adjuvant dosage and spray volume on deposition. Leaves were sprayed under similar laboratory conditions to pre-run-off with 1 mL of a mixture of fenhexamid (Teldor® 500 SC, Bayer) at recommended dose, a fluorescent pigment (SARDI Fluorescent Pigment, 400 g/L EC; South Australian Research and Development Institute) at 0.2 L/100 L, as well as 15 selected commercial adjuvants to manipulate the deposition quality of a given quantity of deposited spray. Spray deposition on leaves was illuminated under black light (UV-A light in the 365 nm region) and visualised under a stereo microscope (Nikon SMZ800) at 10× magnification. Photos of sprayed leaf surfaces were taken with a digital camera (Nikon DMX 1200). Digital images were quantitatively and qualitatively analysed with Image-Pro Discovery version 6.2 for Windows (Media Cybernetics) software, to determine spray deposition. The sprayed leaves were inoculated with 5 mg dry airborne conidia of Botrytis cinerea in a spore settling tower and incubated for 24 h at high relative humidity (≥ 93%). Leaf discs were isolated onto Petri dishes with paraquat-amended water agar and rated 11 days later for development of B. cinerea from isolated leaf discs. B. cinerea incidence on the upper and lower surfaces of water sprayed leaves averaged 90.4% and 95.8%, respectively. Despite full spray cover of leaves, applications with fenhexamid alone did not completely prevent infection and resulted in 34.6% and 40.8% B. cinerea incidence on the upper and lower surfaces of leaves, respectively. Through the addition of certain adjuvants, B. cinerea incidences were significantly lower (2.9-17.1% and 10.0-30.8%, respectively), while some adjuvants did not differ from the fungicide-only treatment, even though they might have improved spray deposition. The effects of Hydrosilicote and Solitaire alone and in combination with fenhexamid on germinating Botrytis conidia on leaf surfaces were studied in a histopathology study using epifluorescence microscopy. Distinct differences were observed in conidium mortality, germination and germ tube lengths between adjuvants alone and in combination with the fungicide, which might be attributed to indirect effects of the adjuvant mode of action on B. cinerea. The laboratory study clearly demonstrated the potential of adjuvants to improve the bio-efficacy of a fungicide directly through improved deposition on grapevine leaf surfaces. For the vineyard evaluations, the same fluorometry, photomicrography and digital image analysis protocol were used to assess quantitative and qualitative spray deposits under varying adjuvant dosage and volume applications. The Furness visual droplet-rating technique was initially included to determine optimum spray volume with a STIHL SR400 motorised backpack mistblower by assessment of pigment deposition on Chardonnay leaves under illuminated black light. Both assessment protocols showed that quantitative spray deposition increased with increasing spray volume applications of 40 L/ha to 750 L/ha, but decreased at 900 L/ha, possibly due to run-off. The addition of selected adjuvants at recommended dosage and at 600 L/ha demonstrated the potential of adjuvants to increase quantitative and qualitative deposition significantly on upper and lower leaf surfaces. Agral 90, BB5, Nu-film-P, and Solitaire significantly improved deposition on upper and lower leaf surfaces compared with the fenhexamid only and water sprayed control. Break-thru S 240 and Villa 51 did not improve quantitative deposition, although remarkably better qualitative deposition was obtained. An adjuvant dosage effect (within the registered dosage range) was evident, especially those retained on the upper leaf surfaces. Agral 90 and Nu-film-P affected significant improvement of spray deposition at the higher, but not at the lower dosage tested. Solitaire improved deposition at the lower dosage tested, whereas reduced deposition at the higher dosage was attributed to excessive spray run-off. No significant improvement of spray deposition was observed for both dosages tested with Villa 51. Spray mixtures with adjuvants Agral 90 and Solitaire yielded similar deposition values at 600 L/ha compared with the fenhexamid only control at 900 L/ha, but reduced deposition at the higher spray volume, possibly due to spray run-off. This study clearly demonstrated the potential of adjuvants to improve quantitative and qualitative deposition, but highlights the necessity to match adjuvant dosages and application volumes on the spray target to achieve maximum spray deposition. / AFRIKAANSE OPSOMMING: Effektiewe beheer van vrug- en blaarsiektes soos vaalvrot op wingerde benodig voldoende deponering van die swamdoder op die teikenoppervlak. Verlies aan beheer word gewoonlik aan onvoldoende kwantitatiewe deponering op vatbare wingerddele toegeskryf. Onder ‟n hoë siektedruk kan mislukte beheer ook moontlik toegeskryf word aan swak kwalitatiewe deponering. Die primêre doelwit van spuittegnologie is om deponering te optimaliseer met die plantoppervlak as ‟n belangrike komponent in die spuittoedieningsproses, spesifiek in die retensie van spuitdruppels. Byvoemiddel tegnologie het bewys dat oppervlak-aktiewe-agente verbeterde benatting en verspreiding van druppels op die teiken oppervlakte tot gevolg kan hê, en verder ook die deponering en retensie van die aktiewe fungisied bestanddele kan verbeter. Hierdie relatiewe nuwe spuittegnologie op wingerd- en hortologiese verbouing, asook die moontlike effekte van byvoegmiddels op epikutikulêre waks om siekte ontwikkeling te beïnvloed, moet ondersoek word. Verder word nuttige aanbevelings benodig vir byvoegmiddel toedienings by verskillende spuitvolumes en dosisse van die betrokke spuitmengsel. Die doelwit van hierdie studie was, eerstens om die effek van sekere byvoegmiddels op kwantitatiewe en kwalitatiewe spuitbedekking van wingerdblare te bepaal en dan te vergelyk met die biologiese effektiwiteit van ‟n fungisied, en tweedens om van die byvoegmiddels onder veldtoestande te evalueer, asook die effek van byvoegmiddel dosisse en spuitvolumes te bepaal. Blare is onder dieselfde laboratorium toestande tot net voor-afloop met 1 mL van ‟n spuitmengsel, bestaande uit fenhexamied (Teldor® 500 SC, Bayer) teen die aanbevole dosis, ‟n fluoreserende pigment (400 g/L EC; Suid Australiese Navorsing en Ontwikkeling Instituut) teen 0.2 L/100 L, sowel as 15 geselekteerde kommersiële byvoegmiddels gespuit om die kwalitatiewe deponering, vir ‟n gegewe kwantiteit van spuitdeponering, te manipuleer. Die fluoreserende pigment is op die blaaroppervlak belig met ‟n swart lig (UV-A ligbron in die 365 nm golflengte) en deponering is onder ‟n stereo mikroskoop (Nikon SMZ800) teen 10× vergroting waargeneem. Die gespuite blaaroppervlaktes is op die manier met ‟n digitale kamera afgeneem (Nikon DMX 1200), waarna die digitale foto‟s kwantitatief en kwalitatief deur die gebruik van „Image-Pro Discovery version 6.2 for Windows (Media Cybernetics)‟ sagteware geanaliseer is om spuitbedekking te bepaal. Na elke blaarspuit is die blare met 5 mg droë konidia van B. cinerea in ‟n inokulasietoring geïnokuleer en daarna vir 24 h onder hoë relatiewe humiditeit (≥ 93%) geïnkubeer. ‟n Aantal skyfies vanuit elke blaar is op Petri bakkies met paraquat medium geïsoleer en 11 dae later is die persentasie van B. cinerea ontkieming bepaal. Die gemiddelde voorkoms van B. cinerea op die blare wat slegs met water gespuit is, was 90.4% op die boonste en 95.8% op die onderste blaaroppervlaktes. Spuitbehandelings met slegs fenhexamied, ongeag goeie blaarspuitbedekking, kon nie die B. cinerea infeksie ten volle voorkom nie, en infeksie van gemiddeld 34.6% en 40.8% is onderskeidelik op die boonste- en op die onderste blaaroppervlaktes waargeneem. Met die byvoeging van sekere byvoegmiddels het die voorkoms van B. cinerea betekenisvol verminder (2.9-17.1% en 10.0-30.8%, onderskeidelik), terwyl ander byvoegmiddels nie van die fenhexamied behandeling verskil het nie, hoewel hierdie middels meestal wel spuitdeponering verbeter het. Die effek van slegs Hydrosilicote en Solitaire, en in kombinasie met fenhexamied op ontkiemende Botrytis conidia, is bestudeer in ‟n histopatologiese studie deur middel van die gebruik van epifluoresensie mikroskopie op die blaaroppervlak. Duidelike verskille in die aantal dooie konidia, ontkiemingpersentasies en kiembuislengtes is tussen die byvoegmiddels en in kombinasie met fenhexamied waargeneem, waar sommige waarnemings moontlik aan die indirekte effek van die byvoegmiddel op B. cinerea toegeskryf kan word. Hierdie laboratoriumstudie wys duidelik dat byvoegmiddels oor goeie potensiaal beskik om die bio-effektiwiteit van die fungisied te verbeter deur die direkte verbetering van deponering op die wingerdblaaroppervlak. Dieselfde fluorometrie, fotomikrografie en digitale foto-analise protokol is in ‟n wingerd evaluasie om die kwantitatiewe en kwalitatiewe spuitdeponering van verskillende byvoegmidel dosisse and spuitvolumes te bepaal, gebruik. Die Furness visuele druppel meting tegniek is aanvanklik ingesluit om die optimale spuit volume met ‟n „STIHL SR400 motorised backpack mistblower‟ te bepaal deur visuele meetings van gedeponeerde pigment op Chardonnay blare onder ‟n swart ligbron. Beide protokolle wys dat kwantitatiewe spuitbedekking met ‟n toename in spuit volumes 40 L/ha tot 750 L/ha verbeter het, maar afgeneem het teen 900 L/ha, moontlik as gevolg van druppel-afloop. Die byvoeging van ‟n byvoegmiddel teen die aanbevole dosis en 600 L/ha wys uitstekende potensiaal om kwantitatiewe en kwalitatiewe deponering betekenisvol op boonste en onderste blaaroppervlaktes te verbeter. Agral 90, BB5, Nu-film-P, en Solitaire het deponering betekenisvol op boonste en onderste blare in vergelyking met die fenhexamied alleen en die water kontrole verbeter. Break-thru S 240 en Villa 51 het nie kwantitatiewe deponering verbeter nie, alhoewel verbeterde kwalitatiewe bedekking met hierdie produkte waargeneem is. ‟n Byvoegmiddel dosis effek (binne die registreerde dosis reeks) was duidelik waarneembaar, veral vir druppel retensie op die boonste oppervlak van blare. Agral 90 and Nu-film-P verbeter die spuit deponering betekenisvol met die hoër getoetste dosis, maar nie teen die lae dosis nie. Solitaire verbeter egter die deponering teen die laer dosis, maar minder deponering teen ‟n hoër dosis kan moontlik toegeskryf word aan oormatige druppel-afloop. In die geval van Villa 51 was geen betekenisvolle verbetering van spuitdeponering vir beide die behandelingsdosisse waargeneem nie. Spuitmengsels met byvoegmiddels, Agral 90 en Solitaire, het soortgelyke deponerings gelewer teen 600 L/ha in vergelyking met die fenhexamied kontrole teen 900 L/ha, maar deponering neem af teen hoër spuitvolumes met byvoegmiddels moontlik as gevolg van druppel-afloop. Hierdie studie wys duidelik die uitstekende potensiaal van Byvoegmiddels om kwantitatiewe en kwalitatiewe deponering te verbeter, maar beklemtoon die noodsaaklikheid van die korrekte gebruik van byvoegmiddel dosis en volume om die maksimum spuitdeponering op die teiken te verkry.
142

Infection by dry, airborne Botrytis cinerea conidia and fungicide efficacy on different parts of grape bunches and vinelets

Van Rooi, Cicelia 03 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The evaluation of fungicide efficacy in commercial vineyards can be influenced by the sporadic occurrence of Botrytis cinerea at various positions on vines, differences in bunch structure during bunch development and the phenomenon that symptom expression in shoots and bunches is governed by the resistance reaction of the various shoot and bunch parts. It has been postulated that, following air and water dispersal, infection by solitary conidia should playa prominent role in the epidemiology of B. cinerea on grapevine. The aim of this study was to determine (i) infection and (ii) fungicide efficacy at specific sites on shoots of vinelets and bunches (table grape cultivar Dauphine and the wine grape cultivar Merlot) inoculated with dry, airborne conidia of B. cinerea. Vinelets, prepared from cuttings, and bunches obtained from the vineyards at full bloom, pea size, bunch closure, véraison and harvest stages, were sprayed in a spray chamber at the recommended dosages with iprodione, pyrimethanil, cyprodinil/fludioxonil and fenhexamid or were left unsprayed. After 24 h the vinelets or bunches were dusted with dry conidia of Botrytis cinerea in a settling tower and incubated for 24 h at a high relative humidity (±93%). Following incubation, both the vinelets or bunches were divided into three groups. Vinelets and bunches of the one group were surface-sterilised, the others were left unsterile. Vinelets and bunches of one unsterile group were placed in dry chambers, kept for 14 days at 22°C with a 12 h photoperiod daily and monitored for symptom expression and the development of B. cinerea. Vinelets and bunches of the sterile group, and from one unsterile group were used for isolation. From each of these vinelets leaf blades, leaf petioles, shoots and inflorescences were removed. Sites used for isolation in bunch parts were rachises, laterals and pedicels, and sites on berries were the pedicel-end, cheek and style-end. The different parts and segments were placed in Petri dishes on Kerssies' B. cinerea selective medium, or on water agar medium supplemented with paraquat and incubated for 14 days at 22°C with a 12 h photoperiod daily. Infection and fungicide efficacy was determined by observing intact vinelets and bunches for symptom expression, and by estimating the amount of B. cinerea at the various sites on the vinelets and bunches with isolation studies. No symptoms of B. cinerea decay developed on sprayed and unsprayed vinelets that were kept in dry chambers during the 2 wk observation period. The isolation and incubation studies showed that the different fungicides were highly and nearly equally efficient in reducing superficial B. cinerea inoculum and latent infection. .In the case of leaf blades, which showed a high amount of B. cinerea on unsprayed vinelets under the two sterility regimes, decay was significantly reduced by each fungicide on both cultivars. This was not the case for the other parts, which yielded B. cinerea at low incidences under the two sterility regimes. The study with bunches showed that dry, airborne conidia, and the fungicide sprays, penetrated loose and tight clustered bunches from bloom to harvest and evenly landed on the various bunch parts. At full bloom, the amount of B. cinerea in unsprayed bunches was high on the laterals and pedicels, but low on the embryos. Unsprayed intact bunches at full bloom were highly susceptible to B. cinerea and developed symptoms of grey mould. The fungicides inhibited symptom expression at full bloom, but could not prevent infection. Unsprayed bunches inoculated at the other stages remained asymptomatic. The amount of B. cinerea was generally high in the rachises and laterals at pea size and bunch closure stages, and in the pedicel end of berries at harvest. Infection was constantly low in the berry cheek. The fungicides had a differential effect on infection at the various sites. In the case of rachises, the amount of B. cinerea was at each growth stage drastically reduced by each fungicide. In laterals, it was effectively reduced at pea size and bunch closure. However, at these two sites, significant differences were found between the fungicides in efficacy at stages when the amount of B. cinerea was high. This study showed that if these fungicides are applied properly to vine in commercial vineyards between budding and prebloom, during flowering, and at bunch closure, they should effectively prevent infection and symptom expression and thus the development of B. cinerea epiphytotics. / AFRIKAANSE OPSOMMING: INFEKSIE DEUR DROË, LUGGEDRAAGDE BOTRYTIS CINEREA KONIDIA EN DIE EFFEK VAN FUNGISlEDE OP VERSKILLENDE SETELS BINNE WINGERDTROSSE EN OP LOTE: Evaluering van fungisieddoeltreffendheid in kommersiële wingerde word beïnvloed deur die sporadiese voorkoms van Botrytis cinerea op verskeie posisies van wingerddele, verskille in trosstruktuur tydens trosontwikkeling, en die feit dat simptoomuitdrukking in lote en trosse deur die weerstandsaksie van die verskillende morfologiese dele van lote en trosse beheer word. In die natuur speel infeksie deur enkel konidia 'n prominente rol in die epidemiologie van B. cinerea van wingerd. Die doel van hierdie studie was om (i) infeksie en (ii) die effek van fungisiede op verskillende posisies op lote en trosse (tafeldruif kultivar Dauphine, wyndruif kultivar Merlot), wat met droë, luggedraagde konidia van B. cinerea geïnokuleer is, te bepaal. Lote, verkry vanaf steggies, en trosse versamel vanuit die wingerde tydens blom-, ertjiekorrel-, trostoemaak-, deurslaan- en oesstadium, is teen aanbevole dosisse met iprodione, pyrimethanil, cyprodinillfludioxonil of fenhexamid in 'n spuitkas bespuit, of is onbehandeld gelaat. Na 24 h is die lote en trosse met droë konidia van B. cinerea in 'n inokulasietoring geïnokuleer en daarna vir 24 h onder hoë humiditeit [±93% RH] geïnkubeer. Na inkubasie is die lote en trosse in drie groepe verdeel. Die een groep lote en trosse is oppervlakkig gesteriliseer om die patogeen op die oppervlakte te elimineer, en die ander twee groepe is onbehandeld gelaat. Die lote en trosse van een nie-steriele groep is vir 14 dae in droë voghokke by 22°C met 'n 12 uur daaglikse fotoperiode geplaas, en daagliks vir siekteuitdrukking en die ontwikkeling van B. cinerea gemonitor. Lote en trosse van die ander twee groepe is vir isolasiestudies gebruik. Vanaf elke loot is blaarskywe, blaarstele, internodes en ongeopende blomtrossies verwyder. Vanaftrosse is ragisse, laterale en korreisteie verwyder, en vanaf korrels is skilsegmente aangrensend aan die korrelsteel, die stempel-end, en die wang verwyder. Die dele en segmente is op B. cinerea selektiewe medium, en op paraquat medium in Petri bakkies geplaas en vir 14 dae by 22°C met 'n 12 uur daaglikse fotoperiode geïnkubeer. Infeksie en die fungisiedeffek is bepaal deur die intakte lote en trosse vir siekte- uitdrukking te monitor, en deur die hoeveelheid B. cinerea op verskeie posisies op lote en trosse te bepaal. Geen simptome het op enige posisie op bespuite en onbespuite lote, wat in droë hokke gehou is, ontwikkel nie. Die isolasie- en inkubasiestudies het getoon dat die verskillende fungisiede hoogs effektief op lote was, en inokulumvlakke van die patogeen doeltreffend verlaag het. In die geval van blaarskywe, wat hoë vlakke van B. cinerea op onbespuite steggies onder die twee steriliteitskondisies getoon het, is verrotting op beide kultivars betekenisvol deur die fungisiedes verlaag. Dit het egter nie vir die ander dele, waarop daar 'n lae voorkoms van B. cinerea onder die twee steriliteitskondisies was, gegeld me. Die studie met trosse het getoon dat droë, luggedraagde konidia en fungisiednewels beide oop en kompakte trosse vanaf blomstadium tot oes penetreer en eweredig op die verskillende dele land. Met blomstadium was die hoeveelheid B. cinerea in onbespuite trosse hoog op laterale en korrelstele, maar laag op die embrios. Onbespuite, intakte trosse was hoogs vatbaar vir B. cinerea by blomstadium en het simptome van vaalvrot ontwikkel. Die fungisiede het siekte-uitdrukking by blomstadium voorkom, maar kon nie infeksie voorkom me. Onbespuite trosse wat op ander stadia geïnokuleer is, het geen siekte-uitdrukking getoon me. Die hoeveelheid B. cinerea was hoër in die ragi, asook in laterale by ertjiekorrel- en trostoemaak stadium, en hoër in korreisteie by oesstadium. Infeksie was konstant laag in die korrelskil. Die fungisiede het 'n differensiële effek op infeksie by die verskillende posisies gehad. In die geval van ragi was die hoeveelheid B. cinerea drasties deur elke fungisied by alle groeistadia verlaag. In laterale was dit effektief by ertjiekorrel- en trostoemaakstadium verminder. By hierdie twee posisies waar die hoeveelheid B. cinerea hoog was, is daar egter betekenisvolle verskille in die doeltreffendheid van fungisiedes gevind. Hierdie studie toon dat as fungisiede behoorlik in kommersiële wingerde tussen botvorming en blomstadium, en tydens blom- en trostoemaakstadium toegedien word, infeksie en siekte-uitdrukking, en dus ook die epifitotiese ontwikkeling van B. cinerea, voorkom behoort te word.
143

Ecological relevance of suborganismal and population responses of terrestrial oligochaeta to the fungicide copper oxychloride

Maboeta, Mark Steve 12 1900 (has links)
Thesis (Ph.D)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Copper oxychloride is a fungicide that is extensively used in vineyards in the Western Cape to treat and prevent fungal diseases. It is however not clear what the effects are on soil organisms, which play an important role in soil fertility, in South African soils. There is paucity of data linking results obtained in the laboratory to effects observed in the field, which will only become useful if a clear relation can be demonstrated. The aims of this study were to: ~ Determine the effects of copper oxychloride on field populations of earthworms and simultaneously monitor lysosomal membrane stability, measured as neutral red retention time (NRRT). ~ Validate experimental field studies by doing inventories of earthworm populations in long-term sprayed vineyards. ~ Determine the LC50 of copper oxychloride and simultaneously measuring NRRT, and linking them to the experimental field studies. ~ Conduct bioassays, burrowing activity- and soil-avoidance experiments to investigate their relations to earthworm population responses in the experimental field studies. Earthworms were sampled by hand-sorting in the field tests on treated and untreated field plots in the Western- (October 1998 - July 1999) and Northern Cape (April 1998 - October 1999). Soil samples and worms were analysed for copper contents and coelomocytes of live earthworms were used to conduct the neutral red retention assays. Acute toxicity tests were conducted over a period of 28 days during which the earthworms (Eisenia fetiday were exposed to different concentrations of copper oxychloride. Change in biomass and mortality were measured as endpoints, as well as NRRT. Bioassays, burrowing activity and soil-avoidance were conducted by exposing Aporrectodea caliginosa to grassland- and vineyard soil as well as grassland soil spiked with 60 J.1g.g-1copper in the form of copper oxychloride. Growth and mortality were recorded in the bioassays as well as copper concentrations In earthworm body tissues and substrates used over a period of28 days. Burrowing activity and soil-avoidance were determined by measuring the length of tunnels burrowed by A. caliginosa in soil profiles over a period of 4 days under different exposure regimes. Results from the field tests showed that spraying of copper oxychloride had a negative effect on earthworm populations at the prescribed application rates. NRR T in earthworms from the exposure plots was significantly (p<0.05) lower after just one spraying application. It was concluded that spraying copper oxychloride at prescribed application rates caused a decrease in field populations of earthworms and that NRRT was an early and reliable biomarker since it was indicative of later effects observed at the population level. Results obtained from the field inventory of earthworms in vineyards at Nietvoorbij, Robertson end Worcester confirmed data from the two field studies. The calculated LC50 of 882.78 I1g.g-1 for copper oxychloride and 519.40 I1g.g-1 for copper was ecologically relevant if a safety factor of 10 was applied. NRRT which manifested earlier than effects on biomass change in the acute toxicity tests, were significant when viewed against the background of responses of field populations of earthworms. From the bioassay experiments it was found that A. caliginosa exposed to copper oxychloride spiked soil had significantly (p<0.05) higher weight loss and mortality than those in grassland- and vineyard soil. This indicated that changes in biomass and mortality were indicative of population responses in the field and can be considered as ecologically relevant. Burrowing activity of A. caliginosa was significantly (p<0.05) lower in vineyard and copper oxychloride spiked soil than in grassland soil. Similarly in the soil avoidance experiments it was found that A. caliginosa avoided vineyard- and copper oxychloride contaminated soil. It is therefore concluded that burrowing activity and soil avoidance were ecologically relevant endpoints since they corresponded with population responses in the field. The study thus revealed that the long-term usage of copper oxychloride could have negative effects on earthworm populations. The spraying of copper oxychloride can have important implications on the sustainable use of agricultural soils since earthworms and other soil organisms play such an important role in soil fertility. The use of biomarkers and other ecotoxicological indicators can provide an early warning that soil organisms are under environmental stress. / AFRIKAANSE OPSOMMING: Die fungisied koperoksichloried word wyd gebruik in die Wes-Kaap om swamsiektes in wingerde te beheer en te voorkom. Dit is egter nie bekend wat die effek daarvan op Suid Afrikaanse grondbiota, wat 'n belangrike rol speel in grondvrugbaarheid, is nie. Daar is ook 'n tekort aan inligting wat die resultate van laboratoriumondersoeke in verband bring met veldstudies. Die doelstellings van die studie was om: ~ Die effek van koperoksichloried op erdwurmpopulasies in die veld te ondersoek en terselfdertyd membraanstabiliteit, as moontlike biomerker, gemeet as neutraal rooi retensietye (NRRT), te monitor. ~ Die geldigheid van eksperimentele veldstudies te toets deur ook grondanalises te doen in wingerde wat oor langtermyn met koperoksichloried bespuit is. ~ Die LC50 van koperoksichloried vir erdwurms te bepaal en terselfdertyd NRR T te meet asook om dié gegewens in verband te bring met die resultate van seisoenale veldstudies oor die uitwerking op erdwurmpopulasies. ~ Bio-evaluerings ("bioassays"), tonnelaktiwiteit- en vermydingseksperimente te onderneem en die verband tussen die toksiteitstoetse en populasieresponse, soos waargeneem in die veld, te ondersoek. Erdwurms is versamel deur handsortering tydens die veldtoetse in die Wes- (Oktober 1998 - Julie 1999) en Noord-Kaap (April 1998 - Oktober 1999) op kontrole en bespuite persele. Grondmonsters en erdwurms is spektrofotometries geanaliseer om koperinhoude te bepaal. Die selomosiete van lewende wurms is gebruik om NRR T te bepaal. Akute toksisiteitstoetse is uitgevoer oor 'n tydperk van 28 dae waartydens Eisenia fetida blootgestel is aan verskillende koperoksichloried konsentrasies. Veranderinge in biomassa en mortaliteit is bepaal asook NRRT. Bioevaluerings ("bioassays"), tonnelaktiwiteit- en vermydingseksperimente IS uitgevoer deur Aporrectodea caliginosa bloot te stel aan grasveld- en wingerdgrond asook grasveldgrond wat met koperoksichloried gekontamineer is. Groei en mortalitiet is bepaal in die "bioassays" asook koperkonsentrasies in die grond en erdwurm liggaamsweefsels oor 'n tydperk van 28 dae. Tonnelaktiwiteit en grondvermyding is bepaal deur die lengte van tonnels wat deur A. caliginosa gegrawe is te meet oor 'n tydperk van vier dae vir die verskillende blootgestelde groepe. Die resultate het aangedui dat koperoksichloriedbespuiting 'n negatiewe invloed het op erdwurmpopulasies teen die voorgeskrewe toedieningsprogram. NRRT in erdwurms van die blootstellingperseel, was beduidend (p<0.05) laer na 'n enkele bespuiting. Daar is verder bevind dat NRR T 'n betroubare en vroeë biomerker is, aangesien dit 'n aanduiding gegee het van latere effekte wat op populasievlak na vore getree het. Veldopnames in Nietvoorbij, Robertson en Worcester het die geldigheid van data verkry uit die veldstudies ondersteun. Die berekende LC50 van 882.78 ug.g" vir koperoksichloried en 519.40 ug.g" VIr koper was ekologies relevant indien 'n veiligheidsfaktor van 10 toegepas is. NRRT se ekologiese relevansie is bevestig deur dit te vergelyk met response wat in die veldtoetse waargeneem is. Deur bioevalueringseksperimente is bevind dat gewigsverlies en mortaliteit van A. caliginosa beduidend hoër was in koperoksichloried gekontamineerde grond as in die grasveld- (kontrole) en wingerdgronde. Veranderinge in biomassa en mortalitiet was aanduidend van populasieresponse soos waargeneem in die veldstudies en kan dus as ekologies relevante eindpunte beskou word. Tonnelaktiwiteit van A. caliginosa was beduidend (p<0.05) laer in wingerd- en koperoksichloried gekontamineerde grond as in grasveldgrond. Dieselfde is gevind in die grondvermydingstoetse waar A. caliginosa wingerd- en koperoksichloried gekontamineerde grond vermy het. Dit kan dus afgelei dat tonnelaktiwiteit en grondvermyding ook ekologies bruikbare eindpunte is aangesien dit verband hou met populasieresponse soos waargeneem in die veldstudies. Hierdie studie het getoon dat die herhaalde gebruik van koperoksichloried 'n nadelige invloed kan hê op erdwurmbevolkings. In die lig van die belangrike rol wat erdwurms en ander grondorganismes speel in grondvrugbaarheid kan die oormatige gebruik van hierdie fungisied ernstige implikasies inhou vir volhoubare benutting van landbougronde. Die gebruik van biomerkers en ander ekotoksikologiese eindpunte kan egter as vroeë waarskuwingsmetode dien dat die grondorganismes onder omgewingstres verkeer.
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Efeitos fisiológicos da aplicação de triazol e estrobilurina em soja / Physiological effects of triazole and strobilurin application on soybean

Moura, Paula Caroline Silva 18 February 2013 (has links)
Com o aumento da população mundial, torna-se necessário a busca de tecnologias para o incremento da produção de alimentos. O cultivo da soja (Glycine max (L.) Merrill) destaca-se entre as atividades econômicas mundiais que apresentam crescimentos expressivos nas últimas décadas e apesar da crescente expansão territorial e produção agrícola, tem a produtividade influenciada por fatores externos e internos durante o cultivo, sendo o principal deles, a incidência de doenças. Atualmente, a doença mais preocupante é a ferrugem da soja, causada pelo fungo Phakopsora pachyrhizi Sydow & Sydow. Para o controle desta doença devastadora, recomenda-se a aplicação concomitante de fungicidas triazóis e estrobilurinas, que, conforme alguns dados da literatura, além de atuarem de forma protetora e curativa, apresentam efeitos na produtividade. O objetivo do trabalho foi esclarecer o efeito fisiológico do triazol ciproconazol e da estrobilurina azoxistrobina em plantas de soja sem incidência de ferrugem. O trabalho foi realizado em casa de vegetação no Departamento de Ciências Biológicas da ESALQ/ USP, em Piracicaba, SP no período entre dezembro de 2008 a maio de 2009 com plantas de soja cultivar Pintado. As condições hídricas e do solo foram mantidas conforme as recomendações para a cultura. Os tratamentos foram constituídos pelos fungicidas Ciproconazol (triazol), Azoxistrobina (estrobilurina) e Óleo mineral (Nimbus) e as aplicações realizadas nos estádios R1, R4 (duas aplicações) e R1, R4 R5,4 (três aplicações). Foram analisados aspectos de produção (Número, massa fresca, seca e média das vagens, massa seca de grãos e peso de 100 grãos) e aspectos anatômicos (espessura do limbo foliar, espessura e largura da nervura central, espessura do xilema e do floema), sendo que nestas análises, foram utilizados apenas os tratamentos em que foram realizados três aplicações do fungicida. O delineamento experimental foi em blocos inteiramente ao acaso, com 9 tratamentos e 5 blocos. Os resultados apontam redução no número de vagens por planta, massa fresca e seca das vagens, número de grãos e massa seca de grãos tratados com a mistura entre o triazol e a estrobilurina. Sob o aspecto anatômico, houve incremento na espessura do limbo foliar, espessura e largura da nervura central e a espessura do sistema vascular (xilema e floema). Com base nos dados obtidos no trabalho, conclui-se que, nas condições em que foi realizado, a aplicação do triazol e da estrobilurina em plantas de soja restringe o potencial de produção de grãos no cultivar Pintado. / With increasing world population, it is necessary to search for technologies to increase food production. The cultivation of soybean (Glycine max (L.) Merrill) stands out among the economic activities that present significant growth worldwide in recent decades, and despite the increasing territorial expansion and agricultural production, productivity is influenced by external and internal factors during cultivation , the main one being, the incidence of diseases. Currently, the disease more worrying soybean is rust caused by Phakopsora pachyrhizi Sydow & Sydow. To control this devastating disease, we recommend the application of triazole and strobilurin fungicides, which, according to some literature data, act so protective and curative, and have effects on productivity. The objective of this study was to clarify the physiological effect of the triazole cyproconazole and strobilurin azoxystrobin in soybean without rust incidence. The study was conducted in a greenhouse at the Department of Biological Sciences ESALQ / USP, Piracicaba, SP, Brazil in the period between December 2008 and May 2009 with soybean cultivar Pintado. The soil and water conditions were maintained as recommended for the crop. The treatments consisted of fungicides cyproconazole (triazole), azoxystrobin (strobilurin) and mineral oil (Nimbus) under applications at the stages R1, R4 (two applications) and R1, R4, R5, 4 (three applications). We analyzed aspects of production (number, fresh, dry and average pod dry grain and 100-grain weight) and anatomical aspects (leaf thickness, width and thickness of the midrib, thickness of xylem and phloem), and in these analyzis, we used only the treatments that were performed three applications of fungicide. The experimental design was a randomized block design with 9 treatments and 5 blocks. The results showed a reduction in the number of pods per plant, fresh and dry weight of pods, number of grains and dry grain treated with the mixture of triazole and strobilurin. Under the anatomical aspect, there was an increase in leaf thickness, width and thickness of the midrib and the thickness of the vascular system (xylem and phloem). By the data obtained in the study, it was concluded that, under the conditions in which it was performed, the application of triazole and strobilurin in soybean plants restricts the potential for grain production in the cultivar Pintado.
145

Compatibilidade entre tratamentos químico e biológico de sementes de feijão para controle de Fusarium oxysporum f. sp. phaseoli / Compatibility between chemical and biological treatments in common bean seeds to control Fusarium oxysporum f. sp. phaseoli

Ishizuka, Mariane Sayuri 01 April 2016 (has links)
Atualmente, a produtividade do feijoeiro comum (Phaseolus vulgaris L.) pode ser reduzida devido à ocorrência de doenças em todo o território nacional, destacando-se a murcha de fusário, causada por Fusarium oxysporum f. sp. phaseoli (Fop). No campo, o patógeno é disseminado a longas distâncias através das sementes infectadas e/ou contaminadas e a sua sobrevivência ocorre, principalmente, no solo. Os objetivos deste trabalho foram: avaliar a inibição do crescimento micelial de Fop por Trichoderma spp.; classificar a sensibilidade in vitro de Fop e Trichoderma spp., separadamente, a fungicidas e verificar a compatibilidade entre fungicidas químicos e biológicos para controle de Fop, presente nas sementes e no solo. Para avaliar a inibição do crescimento micelial de Fop, foram utilizados três isolados do patógeno, os quais foram confrontados, in vitro, com três isolados de Trichoderma spp. em testes de cultura pareada e produção de metabólitos voláteis a 20-22°C. Os experimentos foram conduzidos em delineamento inteiramente casualizado, com cinco repetições para cada isolado de Trichoderma. Para a classificação da sensibilidade in vitro de Fop e Trichoderma a fungicidas, foram avaliados os mesmos isolados anteriormente utilizados. Foram comparados dez fungicidas, em doses entre 0 a 100 mg L-1 que foram ajustadas de acordo com a CI50 de cada fungicida. Com base na percentagem de inibição do crescimento micelial, foram estimados os valores da concentração inibitória de 50% (CI50) e 100% (CI100) e selecionaram-se os fungicidas compatíveis com Trichoderma spp. A compatibilidade entre tratamentos químico e biológico foi avaliada através da inoculação artificial de sementes de feijão com um isolado de Fop (IAC 11.299-1) e infestação do mesmo no solo. As sementes foram tratadas com os fungicidas fludioxonil, flutriafol e tiofanato metílico, e com os três produtos biológicos, separadamente e em misturas. Avaliou-se o efeito dos tratamentos por meio dos testes de sanidade, germinação, comprimento de plântulas, massa da matéria seca em laboratório e índice de velocidade de emergência e porcentagem de emergência em estufa não climatizada. O efeito protetor dos tratamentos foi verificado através do teste de transmissão do patógeno solo-planta. Todos os isolados de Trichoderma apresentaram antagonismo in vitro contra Fop. No teste de cultura pareada foi observada uma redução de 15 a 20% no crescimento micelial do patógeno. No teste de produção de metabólitos voláteis, o isolado T12-1086G05 foi responsável pela maior inibição do crescimento micelial de Fop (10 a 48%). Os testes de sensibilidade in vitro mostraram que tiofanato metílico, flutriafol e fludioxonil foram compatíveis com Trichoderma (CI50 > 2 mg L-1). Com exceção do flutriafol e do GF 422 isolados e em mistura, todos os tratamentos foram eficientes na erradicação de Fop nas sementes, sem afetar a sua qualidade fisiológica. No teste de transmissão, verificou-se que a incidência de Fop foi de 5 a 40% no hipocótilo e de 5 a 30% nas raízes de feijoeiro provenientes de sementes tratadas com os produtos. / Currently, the common bean (Phaseolus vulgaris L.) productivity can be reduced due to the occurrence of diseases in all over the country, especially Fusarium wilt, caused by Fusarium oxysporum f. sp. phaseoli (Fop). In the field, the pathogen is spread to long distances through infected and/or contaminated seeds and its survival occurs, mainly, in the soil. The objectives of this work were: to evaluate the micelial growth inhibition of Fop promoted by Trichoderma spp.; to classificate in vitro sensitivity of Fop and Trichoderma spp., separately, to fungicides and to verify the compatibility between chemical and biological fungicides to control Fop, applied on the seeds and on the soil. To evaluate the micelial growth inhibition of Fop, it was used three Fop isolates, which were in vitro confronted with three isolates of Trichoderma spp., by paired culture and antibiosis assays at 20-22°C. The experiments were conducted entirely casualized design, with five replications for each Trichoderma isolate. For the in vitro sensitivity classification, it was evaluated the same isolates of Fop and Trichoderma previously used. It was compared ten fungicides and the concentrations of 0 to 100 mg L-1, which were adjusted according to the IC50 of each fungicide. Based on the percentage of micelial growth inhibition, it was estimated the values of inhibitory concentration of 50% (IC50) and 100% ((IC100) and it was selected the compatible fungicides with Trichoderma spp. The compatibility between chemical and biological treatments were evaluated through artificial inoculation of common bean seeds with the Fop isolate IAC 11.299, following the infestation of the pathogen in the soil. Seeds were treated with fludioxonyl, flutriafol and tiofanate methyl, and with three biological products, separately and mixed. It was evaluated the treatment effects by the following assays: sanity, germination, seedling lenght, seedling dry matter in laboratory conditions and emergence speed rate and percentage of emergence in greenhouse conditions. The protective effect of the treatments was verified through the pathogen transmission experiment from soil to plant. All Trichoderma isolates showed in vitro antagonism against Fop. In the paired culture assay it was observed 15 to 20% reduction in the pathogen micelial growth. In the antibiosis assay, the isolate T12-1086G05 was responsible for the maximum micelial inhibition growth of Fop (10 to 48%). in vitro sensitivity experiments showed that thiofanate methyl, flutriafol and fludioxonyl were compatible with Trichoderma (IC50 > 2 mg L-1). Except the treatments with fluatrifol and GF 422 alone and in mixture, all the products were efficient in eradicating Fop in the seeds, without affect its physiological quality. In the transmission experiment, it was verified that the Fop incidence was 5 to 40% in the hypoticol and 5 to 30% in the common bean roots from seed treated with the products.
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Avaliação dos efeitos dos parabenos sobre organismos aquáticos e comparação de sensibilidade de espécies / Ecotoxicological effects of parabens on aquatic organisms and comparison of species sensitivity

Spadoto, Mariângela 05 June 2017 (has links)
Os parabenos são conservantes utilizados em alimentos, fármacos, cosméticos e produtos de cuidado pessoal. Pertencem à família de ésteres do ácido p-hidróxibenzoico, distinguindo-se entre si pelo comprimento e ramificação da cadeia lateral alquílica. Nesse contexto, o objetivo principal dessa tese foi avaliar os efeitos dos dois parabenos mais frequentemente utilizados (metilparabeno e propilparabeno) sobre diferentes espécies de ambientes aquáticos. Para isso, inicialmente, foram realizados testes de toxicidade de curta duração com cinco espécies de organismos de diferentes grupos taxonômicos e funcionais, sendo quatro delas de regiões tropicais (Ceriodaphnia silvestrii, Chironomus xanthus, Macrothrix flabelligera e Hydra viridissima) e uma pertencente às regiões temperadas (Hydra attenuata). Os resultados obtidos nesses testes foram comparados com os resultados de literatura aberta, mostraram que Ceriodaphnia silvestrii (MeP CE50=7,56 mgL e PrP, CE50=2,90 mgL) e Macrothrix flabelligera apresentaram-se mais sensíveis em comparação aos organismos padrão de clima temperado. Num segundo momento, foram realizados testes de toxicidade com sete espécies de fungos hifomicetos aquáticos (Articulospora tetracladia Ingold, Flagellospora curta Webster, Heliscus lugdunensis Sacc. & Thérry, Lemonniera aquatica Wildeman, Lemonniera pseudofloscula Dyko et al., Tetracladium apienses R.C. Sinclair & Eicker, Tetracladium marchalianum Wild.) expostas ao conservante propilparabeno, por possuir maior ação antifúngica. Lemonniera aquatica apresentou maior sensibilidade ao propilparabeno, sendo o mais sensível de todos os fungos testados, bem como dos demais organismos aquáticos reportados na literatura. Além de confirmarem que os parabenos representam risco ecológico potencial para os ambientes aquáticos, os resultados obtidos permitiram concluir que há diferenças de sensibilidade entre as espécies tropicais e temperadas e, por isso, as espécies nativas são mais indicadas para se avaliar os efeitos tóxicos dos parabenos nos ambientes. Dada a presença e persistência dos compostos estudados por entrada contínua no ambiente, a magnitude das concentrações determinadas (ng L-1 e &#956;g L-1), a carência de informações relativas à toxicidade e ao risco que representam para os ecossistemas tropicais, incluindo os do Brasil, sugere-se a implantação pelas agências reguladoras de medidas mais restritivas para o uso desses conservantes, visando uma melhor proteção da biota aquática. / Parabens are preservatives used in foods, pharmaceuticals, cosmetics and personal care products. They belong to the family of esters of p-hydroxybenzoic acid, distinguishing each other by the length and branching of the alkyl side chain. The main objective of this thesis was to evaluate the effects of the two most commonly used parabens, methylparaben and propylparaben, on aquatic species. For this purpose, short-term toxicity tests were initially carried out on five species of organisms from different taxonomic and functional groups: four of them from tropical regions, Ceriodaphnia silvestrii, Macrothrix flabelligera, Chironomus xanthus and Hydra viridissima, and one belonging to temperate regions, Hydra attenuata. The results obtained in these tests were compared with the results of the open literature, showing that Ceriodaphnia silvestrii (MeP, EC50 = 7.56 mg L-1 and PrP, EC50 = 2.90 mg L-1) and Macrothrix flabelligera (MeP, EC50 = 8.04 mg L-1 and PrP, EC50 = 3.85 mg L-1) were more sensitive compared to the standard organisms of temperate climate. Secondly, toxicity tests were performed with seven species of aquatic hyphomycetes fungi and only with the preservative propylparaben, because they have a higher antifungal action: Articulospora tetracladia Ingold, Flagellospora curta Webster, Heliscus lugdunensis Sacc. & Thérry, Lemonniera aquatica Wildeman, Lemonniera pseudofloscula Dyko et al., Tetracladium apienses R.C. Sinclair & Eicker, Tetracladium marchalianum Wild. Lemonniera aquatica showed greater sensitivity to propylparaben (EC50 = 1.63 mg L-1), being more sensitive than all fungi, as well as other aquatic organisms. Thus, the results obtained in the present thesis indicate that there is a difference in sensitivity between tropical and temperate species when exposed to parabens, with tropical native species being more sensitive to the effects of these compounds. Given the presence and persistence of the compounds studied by continuous entry into the environment, the magnitude of the concentrations determined (ng L-1 and &#956;g L-1), the lack of toxicity and risk information for tropical ecosystems, including Brazil, it is suggested that regulatory agencies implement more restrictive measures for the use of these preservatives, aiming at a better protection of the aquatic biota.
147

Sensibilidade in vitro de isolados de Alternaria grandis e Alternaria solani a fungicidas / In vitro sensitivity of Alternaria grandis and Alternaria solani to fungicides

Nossllala, Shadia Katari 07 February 2017 (has links)
Atualmente, a produtividade da cultura da batata (Solanum tuberosum L.) pode ser reduzida devido à ocorrência de doenças em todo o território nacional, destacando-se a pinta preta, causada por Alternaria spp. Historicamente se acreditava que A. solani (AS) era a principal causadora mas, atualmente, descobriram outras espécies associadas, sendo predominante hoje, em território nacional a espécie A. grandis (AG). O objetivo deste trabalho foi avaliar a sensibilidade in vitro de três isolados de A. grandis e um isolado de A. solani frente a onze fungicidas amplamente utilizados no manejo desta doença em campo. Foi avaliado o efeito dos fungicidas sobre o crescimento micelial dos isolados, utilizando-se do método da incorporação do fungicida no meio de cultura fundente. As diluições dos fungicidas foram realizadas em água destilada e esterilizada, de acordo com a metodologia descrita por Camargo (2013) e Ishizuka (2016). Para os fungicidadas com mistura de ingrediente ativo, considerou-se a soma das concentrações no cálculo. Inicialmente, as concentrações do meio de cultura, foram 100, 10, 1, 0,1, 0,01 e 0,001 mg L-1. Após, as doses foram ajustadas conforme a CI50 de cada fungicida. Quantificou-se também a inibição sobre a germinação dos conídios nas contrações discriminatórias de 0; 0,1; 1; 10 e 100 mg.L-1 .24 horas após o preparo do meio as placas foram observadas em microscópio óptico, determinando-se a germinação dos conídios em 300 unidades observadas por placa de Petri. Todos os isolados testados foram altamente sensíveis aos ingredientes ativos fluazinam, pirimetanil, procimidona e piraclostrobina. Não houve diferenças de comportamento de sensibilidade entre as espécies de A. solani e A grandis que possam caracterizar uma perda de sensibilidade por conta da predominância da espécie de A. grandis associada à pinta preta da batata no Brasil. Encontraram-se evidências de insensibilidade dos isolados de A. grandis e A. solani aos ingredientes ativos Clorotalonil e Boscalida. / Currently, the productivity of potato crop (Solanum tuberosum L.) may be reduced due to the occurrence of disease throughout the country, especially due to early blight, caused by Alternaria spp. Historically it was believed that A. solani (AS) was the main cause, most currently was founded others associated species, being predominant today the occurrence of the disease associated with the species A. grandis (AG). The objective of this study was to evaluate the in vitro susceptibility of three isolates of A. grandis and one isolate of A. solani for eleven fungicides widely used in the management of this disease in the field, was evaluated the effect of fungicides on mycelial growth using the fungicidal method that incorporate it in the medium culture. Dilutions of fungicides were performed in sterile distilled water according to the methodology described by Camargo (2013) and Ishizuka (2016). For the fungicidates with active ingredient mixture, was considered the sum of the both concentrations in the calculation.The concentrations of the culture medium were 100, 10, 1, 0.1, 0.01 and 0.001 mg L-1. The doses were adjusted according to the CI50 of each fungicide, was quantified also the inhibition of spore germination, and the fungicides were incorporated into the agar medium - water in discriminatory contractions of 0; 0.1; 1; 10 and 100 mg.L-1 . Then, 24 hours after preparation of the medium the plates were observed under an optical microscope, determining the spore germination observed at 300 units per plate. All tested isolates were highly sensitive to the active ingredients fluazinam, pyrimethanil, procymidone and pyraclostrobin. There was no sensitivity behavioral differences between species of A. solani and A. grandis which may characterize a loss of sensitivity due to the predominance of species of A. grandis associated with early blight in Brazil, was found evidences of insensitivity of isolates of A. grandis and A. solani to the active ingredients Chlorothalonil and Boscalida.
148

Controle de mofo-cinzento (amphobotrys ricini) da mamoneira (ricinus communis l.) por métodos químico, biológico e com óleos essenciais

Chagas, Haroldo Antunes [UNESP] 05 February 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-05Bitstream added on 2014-06-13T19:07:30Z : No. of bitstreams: 1 chagas_ha_me_botfca.pdf: 1461839 bytes, checksum: e3cb655599f9ae29650f6b80ac395c35 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A mamoneira (Ricinus communis L.) é uma espécie oleaginosa tropical, sendo o óleo extraído de suas sementes um dos mais versáteis da natureza e com inúmeras aplicações industriais. Embora ainda seja uma espécie rústica, ela está sujeita a diversas doenças, dentre elas o mofo-cinzento, causada pelo fungo Amphobotrys ricini. O melhoramento genético seria a melhor alternativa para o controle da doença, mas demanda tempo para se obter cultivares resistentes. Dessa Maneira, o uso de métodos de controle baseado em métodos químicos, alternativos ou biológicos mostra-se viável em curto prazo. O objetivo do trabalho foi estudar a eficiência de controle do mofocinzento, na cultura da mamoneira, utilizando-se de métodos químico, alternativo e biológico. Para tanto, foram verificados, in vitro, a eficiência de diferentes meios de cultura na esporulação do patógeno e do antagonista C. rosea. Verificou-se, também, a produção de escleródios do patógeno nos meios. Quanto à eficiência dos métodos, verificou-se, in vitro, a eficiência deles na inibição do crescimento micelial e da germinação dos conídios do patógeno. Após desenvolver e validar uma escala diagramática de avaliação de severidade da doença em racemos de mamoneira, verificou-se a eficiência de aplicação do antagonista C. rosea em frutos destacados da mamona inoculados com o patógeno. Em plantas submetidas a condições de estufa e em campo, verificou-se a eficiência dos métodos no controle da doença causada por A. ricini Quanto à esporulação, o melhor meio de cultura para o patógeno foi V8-20%, obtendo 5,7 x 106 conídios/mL. Para o antagonista C. rosea, o melhor meio foi o TJ- 5% (Suco de Tomate), produzindo 4,41 x 106 conídios/mL. O único meio que propiciou abundante produção de escleródios de A. ricini foi o aveia-ágar. Quanto a inibição do crescimento micelial do patógeno... / The castor bean (Ricinus communis L.) is a tropical oily species, and the oil extracted of its seeds is one of most versatile of the nature, with many industrial applications. Even being a rustic species, it still subjects to several diseases, between them the gray mold, caused by the fungus Amphobotrys ricini. The genetic breeding would be the best alternative for the disease control, but spend time to get a resistant cultivar. In this way, the use of methods of control based on chemical, alternative or biological methods shows viable in short time. The aim of this work was to study the efficiency of the control of gray mold, on castor bean crop, using chemical, alternative and biological methods. Therefore, they had been verified, in vitro, the efficiency of different culture medium in the pathogen sporulation and the antagonist C. rosea. The sclerotia production in the culture medium can be also verified. About the efficiency of the methods, in vitro, the inhibition of the mycelial growth and germination of conidia was verified. After to develop and to validate a diagrammatic scale of evaluation of severity of the disease in racemes of castor bean, the efficiency of application of the antagonist C. rosea in inoculated fruits detached of castor bean with the pathogen was verified. In plants submitted to greenhouse and field conditions, the efficiency of the methods in the control of the disease caused by A. ricini was verified About the sporulation, the optimum culture medium for the pathogen was V8-20%, getting 5,7 x 106 conidia/mL. For the antagonist... (Complete abstract click electronic access below)
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Tratamento fungicida e qualidade de sementes de mamona / Fungicide treatment and quality of castor bean seeds

Kobori, Nilce Naomi 01 April 2011 (has links)
O crescente interesse pelo uso de combustíveis renováveis nos últimos anos fez com que culturas oleaginosas, como a mamona, se tornassem importante objeto de estudo. No entanto, para a instalação de campos desta cultura, é imprescindível sementes de boa qualidade. Como não existem defensivos químicos registrados para a ricinocultura, avaliou-se o efeito de tratamentos fungicidas no tratamento de sementes de mamona (Ricinus communis L.), com produtos fungicidas recomendados para sementes de outras espécies oleaginosas. Três lotes do cv. IAC-2028 (provenientes, respectivamente, dos racemos primário, secundário e terciário) e dois lotes do cv. Guarani (lotes comerciais com todos os racemos) foram tratados com os fungicidas: Captan 500 TS, Derosal Plus, Vitavax-Thiram 200 SC, Maxim XL, Thiram 480 TS, Captan 500 TS + Derosal, Vitavax-Thiram 200 SC + Terraclor 750PM, Fegatex e Trichodermil EP. As amostras foram armazenadas em sacos de papel Kraft por um período de seis meses em condições não controladas de temperatura e umidade relativa do ar. As avaliações contemplaram o potencial sanitário e fisiológico das sementes assim que as sementes foram tratadas e após seis meses de armazenamento. O teste de sanidade foi conduzido pelo método de incubação em papel de filtro sem congelamento e a avaliação foi realizada no décimo dia. Os resultados dos testes de sanidade, de germinação, primeira contagem de germinação, envelhecimento acelerado, emergência de plântulas em campo e análise computadorizada de plântulas (SVIS®), mostraram que a maioria dos tratamentos fungicidas reduziram a incidência de patógenos associados às sementes, com destaque para os tratamentos Vitavax-Thiram+Terraclor, seguido de Vitavax-Thiram, Captan+Derosal, Derosal Plus, Captan e Thiram. A análise computadorizada de plântulas apresenta eficiência equivalente aos testes de primeira contagem de germinação e de emergência de plântulas em campo. O teste de raios X é eficiente para avaliar a morfologia interna das sementes e seus reflexos no potencial fisiológico. / The rising interest in using biodiesel as an alternative energy source is turning some oleaginous crops, like castor bean (Ricinus communis L.), become very important. Although its importance, castor bean yields must have high quality seeds. There are no registered chemical products for castor bean crop; this study aimed to verify fungicide treatments in castor bean seeds (Ricinus communis L.), with registered and recommended fungicides for other oil crops species. Three seed lots of the cultivar IAC 2028 (from the first, second and third raceme, respectively) and two seed lots of the cultivar Guarani (commercial lots with the three racemes mixed) were treated using the fungicides: Captan 500 TS, Derosal Plus, Vitavax-Thiram 200 SC, Maxim XL, Thiram 480 TS, Captan 500 TS + Derosal, Vitavax-Thiram 200 SC + Terraclor 750PM, Fegatex and Trichodermil EP. Seeds were stored in paper bags for six months in uncontrolled environment, and the evaluations contemplate the sanitary and physiological quality after seed treatment and after a period of six month storage. The sanitary test was carried out by the blotter incubation method with no freezing and evaluated after ten days. Results of the sanitary test, germination, first count of germination, accelerated aging, seedling emergence in the field and seed vigor imaging system (SVIS®), showed that most of the fungicide treatments reduced fungi incidence of pathogens associated to castor bean seeds. The most efficient fungicides in controlling fungi associated to the seeds, without any damage to the physiological quality, were Vitavax-Thiram+Terraclor, followed by Vitavax-Thiram, Captan+Derosal, Derosal Plus, Captan and Thiram. The computer analysis system has efficiency equivalent to first count germination and seedling emergence in the field. The X-ray test is effective in evaluating the internal morphology of castor bean seeds and its reflection on the physiological potential.
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A importância das abelhas para a cultura do tomateiro / The importance of bees for the tomato crop

Silva Neto, Carlos de Melo e 09 December 2016 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-01-10T16:36:36Z No. of bitstreams: 2 Tese - Carlos de Melo e Silva Neto - 2016.pdf: 1946853 bytes, checksum: efe032887d4f598ce1710e9dff1b46d1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-11T09:50:40Z (GMT) No. of bitstreams: 2 Tese - Carlos de Melo e Silva Neto - 2016.pdf: 1946853 bytes, checksum: efe032887d4f598ce1710e9dff1b46d1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-11T09:50:40Z (GMT). No. of bitstreams: 2 Tese - Carlos de Melo e Silva Neto - 2016.pdf: 1946853 bytes, checksum: efe032887d4f598ce1710e9dff1b46d1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-12-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Improper use of pesticides is negative visiting bees of agricultural crops, reducing the gains in production resulting from pollination. There are no studies on the effect of fungicides on the bees that pollinate crops, and not only insecticides can cause negative effects bees. The tomato production, is that culture is widely carried out in greenhouses, a condition that reduces the use of pesticides, but generates the pollination deficit, reducing the production of fruit. Thus, the objectives of this study are to verify the pesticides used in tomato crop and the list of products with bees the influence of fungicides in the pollination of culture and bee management in protected environment. In this study there were three activities, first a case study with a survey of pesticides used in tomato plantation in Goianápolis, followed by experiment conducted in a greenhouse to check the pollination of tomato by stingless bee Melipona quadrifasciata and last group experiments to verify effect repellency pollinators of tomato by different combinations of fungicides in the field and their respective fruit production, followed by the death of M. quadrifasciata bees in the laboratory with the use of fungicides. The use of 35 pesticides was found, and 40.5% only of the insecticide class, 32.4% are fungicides, 13.5% are miticides and insecticides and only two products used belong to class of fungicides and bactericides and herbicides. Regarding the toxicological classification of the products, 51.4% are classified as moderately toxic, however 17.14% are classified as extremely toxic and highly toxic, amounting to 34.38% for both groups and only 14.2% are classified as low toxicity. Thus, about 97% of the products used have some degree of danger in relation to the environment. 22 (62.85%) of the chemicals used in growing tomato show the dose lethal to A. mellifera, mostly represented by insecticides. As for pollination in the greenhouse, the fruits of tomatoes produced in greenhouses with the presence of bees showed a superiority of 15% in fresh weight and 41.1% in the number of seeds in relation to the fruits produced in an open environment. For tomato indeterminate growth, seed yield is 33% greater when the flower is pollinated and mass production of tomatoes reaches a 16% gain. The results show the relevance of the use of M. quadrifasciata directed pollination in the greenhouse. The mortality rate for M. quadrifasciata in 24 hours valuation was higher for copper hydroxide and Trifloxistrobin and Tebuconazole, being approximately 75% and 50%, respectively. Already Mancozeb, Bacillus subtilis and the witness did not differ among themselves. Thus, the more pesticide applications made on tomato flowers, fewer visits from bees flowers and consequentenente lower the amount of pollen grains deposited on stigmas, reflecting in fruit production. / O uso inadequado dos agrotóxicos é negativo às abelhas visitantes das culturas agrícolas, reduzindo os ganhos em produção resultantes da polinização. Ainda não existem estudos acerca do efeito dos fungicidas sobre as abelhas que polinizam culturas agrícolas, sendo que não somente inseticidas podem causar efeitos negativos às abelhas. A produção do tomateiro também é realizada em casas de vegetação, condição que poderia reduzir o uso de agrotóxicos, porém gera o deficit de polinização, reduzindo a produção de frutos. Assim, os objetivos desta pesquisa são verificar os agrotóxicos utilizados na cultura do tomateiro e a relação desses produtos com as abelhas, a influência de fungicidas na polinização da cultura e o manejo de abelha em ambiente protegido. Neste estudo foram realizadas três atividades, primeiro, um estudo de caso com o levantamento de agrotóxicos utilizado no cultivo do tomateiro em Goianápolis, GO, seguido de experimento conduzido em casa de vegetação para verificar a polinização do tomateiro pela abelha sem ferrão Melipona quadrifasciata e, por último, foram conduzidos dois experimentos para verificar o efeito de repelência de visitantes florais de tomateiro por diferentes combinações de fungicidas em campo e sua respectiva produção de frutos, seguido da mortalidade de abelhas M. quadrifasciata em laboratório com uso dos fungicidas. Foi verificada a utilização de 35 agrotóxicos, sendo 40,5% deles exclusivamente da classe dos inseticidas, 32,4% fungicidas, 13,5% acaricidas e inseticidas e apenas dois produtos utilizados pertenciam à classe dos fungicidas e bactericidas, e um herbicida. Em relação à classificação toxicológica dos produtos, 51,4% classificados como medianamente tóxicos, porém 17,14% classificados como extremamente tóxicos e altamente tóxicos, totalizando 34,38% para os dois grupos, e somente 14,2% classificados como pouco tóxicos. Assim, cerca de 97% dos produtos utilizados apresentam algum grau de periculosidade em relação ao meio ambiente. Do total, 22 (62,85%) dos produtos químicos utilizados no cultivo de tomateiro apresentam a dose letal para A. mellifera, sendo a maioria representada por inseticidas. Quanto à polinização em casa de vegetação, os frutos de tomate produzidos em estufas com presença de abelhas apresentaram uma superioridade de 15% em massa fresca e 41,1% no número de sementes em relação aos frutos produzidos em ambiente aberto. Para o tomateiro de crescimento indeterminado, a produção de semente é 33% maior quando a flor é polinizada e a produção de massa de tomate apresenta ganhos de 16%. Os resultados evidenciam a relevância do uso de M. quadrifasciata direcionado à polinização de plantas do tomateiro em casa de vegetação. A taxa de mortalidade para M. quadrifasciata em 24 horas de avaliação foi maior quando aplicados o Hidróxido de cobre (75%) e a Trifloxistrobina + Tebuconazol (50%). No entanto, nos tratamentos com Mancozeb, Bacillus subtilis e no tratamento testemunha não houve diferenças entre si. Assim, quanto mais aplicações de agrotóxicos realizadas sobre as flores de tomateiros, ocorre menos visitas de abelhas às flores e, consequentenente, menor a quantidade de grãos de pólen depositados nos estigmas, refletindo na produção de frutos.

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