[EN] Citrus spp. (Rutaceae) are the most widely produced fruits and they are grown in over a hundred countries. During postharvest, major losses are caused by fungal diseases, that for decades have been controlled by treatments with synthetic fungicides. However, their use is continuously more restricted by distributors and supermarket chains, which lower the Maximum Residue Level (MRL) to one third of the authorized or even ban the use of certain fungicides. This has loss of efficacy of treatments and development of resistant strains of pathogens. Alternatives are necessary to substitute or combine the use of synthetic fungicides. The objective of the present work was to evaluate alternative treatments against green and blue molds, caused by Penicillium digitatum (Pers.: Fr.) Sacc. and Penicillium italicum Wehmer, respectively. Food additives and GRAS substances were tested in in vivo preliminary tests against green and blue molds. Potassium sorbate (PS) (Chapter 2) and sodium benzoate (SB) (Chapter 1) were the most effective. 60-s dips in 3% (w/v) SB above 50°C reduced by 90% green and blue mold incidence on 'Valencia' oranges after 7 days at 20°C. This treatment was also effective on 'Lanelate' oranges, 'Fino' lemons and 'Ortanique' mandarins, but not on 'Clemenules' mandarins. Heated solutions combining SB with low doses of imazalil (IMZ) were synergistic. In semi-commercial trials with 'Marisol' Clementine mandarins, the combination PS+IMZ at 20°C allowed a significant reduction of the IMZ doses still controlling green mold. A new colorimetric method that employed extraction of PS from macerated fruit, followed by reaction with 2-thiobarbituric acid (Chapter 3) showed that in oranges treated with PS and stored at 15°C, residues declined initially rapidly and later more slowly, until residues stopped declining after 6 d. A brief double-dip rinse in tap water, immediately after immersion of lemons in a 2% (w/v) PS, removed more than 90% of PS residue. Exposure at 33ºC with 15 kPa CO2 for 24 h or 30 kPa O2 for 48 h effectively controlled both green and blue molds after 7 days of incubation at 20ºC, but control of both diseases lowered after 15 days (Chapter 4). Combining PS dip treatments with gas exposure showed a synergistic effect, that maintained the efficacy of combined treatments during 15 days. In cold storage, after 14, 28, and 42 days, green mold incidence on 'Clemenules' and 'Ortanique' mandarins treated with PS dips and 30kPa O2 for 48h was reduced by 100, 96 and 68%, and 100, 97 and 79%, respectively. Again, a synergistic effect between treatments was observed (Chapter 5). Postharvest green mold and blue molds were effectively controlled by fumigation of lemons and oranges for 6 h at 22ºC with two applied dosages of 3000 ¿L L-1 of ammonia that was injected initially and again 2 h later (Chapter 6). Ammonia fumigation controlled an IMZ-resistant isolate of P. digitatum. When fruit were first immersed in 10 or 30 mg L-1 IMZ (about 10% of typical commercial rates) before ammonia fumigation, a single fumigation with 1500 ¿L L-1 of ammonia was adequate to control both diseases and the increase in effectiveness was additive or synergistic. All these treatments, at different degrees, could replace synthetic fungicides or augment IMZ performance in citrus postharvest decay management. The development of green and blue molds on the most commercially important citrus species and cultivars was assessed for four consecutive harvest seasons and associated with fruit quality parameters (Chapter 7). Fruit susceptibility of the cultivars to green mold in increasing order was Nova, Sanguinelli, Ortanique, Lanelate, Navelate, Fortune, Clemenules, Valencia, W. Navel, Oronules, Clemenpons, Marisol, Salustiana, Hernandina, and Nadorcott. Peel characteristics were the most influencing quality parameters on the susceptibility of citrus fruit to green and blue molds. / [ES] Los cítricos (Citrus spp. fam. Rutaceae) son la fruta más consumida a nivel mundial y se cultivan en más de un centenar de países. Durante el manejo en poscosecha, la mayor parte de las pérdidas se deben a enfermedades fúngicas, que durante décadas se han controlado mediante tratamientos con fungicidas de síntesis. Sin embargo, su uso está continuamente más restringido por parte de los distribuidores y cadenas de supermercados, que reducen el Límite Máximo de Residuos (LMR) a un tercio del establecido o incluso prohíben el uso de ciertos fungicidas. Esto ha provocado la pérdida de eficacia de los tratamientos y el desarrollo de cepas de patógenos resistentes a los fungicidas. Se necesitan pues alternativas para sustituir o combinar con el uso de fungicidas de síntesis. El objetivo de este trabajo fue evaluar tratamientos alternativos contra las podredumbres verde y azul, causadas por Penicillium digitatum (Pers.: Fr.) Sacc. y Penicillium italicum Wehmer, respectivamente. Aditivos alimentarios y sustancias GRAS se probaron en test in vivo preliminaries contra los mohos verde y azul. El benzoato sódico (BS; Capítulo 1) y el sorbato potásico (SP; Capítulo 2) fueron los más eficaces. Baños de 60 s en 3% (p/v) BS sobre 50°C redujeron en un 90% la incidencia de las podredumbres verde y azul en naranjas 'Valencia Late' tras 7 días a 20°C. Estos tratamientos fueron también efectivos en naranjas 'Lanelate', limones 'Fino' y mandarinas híbridas 'Ortanique', pero no en mandarinas 'Clemenules'. La combinación de baños calientes de BS con dosis bajas de imazalil (IMZ) fueron sinérgicas. Un nuevo método colorimétrico que empleó la extracción del SP de la fruta macerada, seguido de una reacción con ácido 2-tiobabitúrico (Capítulo 3) mostró que en naranjas tratadas con SP almacenadas a 15°C, los residuos descendieron rápidamente al inicio y lentamente más tarde, hasta que dejaron de descender tras 6 días. Un doble aclarado rápido con agua corriente inmediatamente después de la inmersión de limones en SP al 2% (p/v), eliminó más del 90% del residuo de SP. Los choques gaseosos a 33ºC y 15kPa CO2 durante 24 h o 30 kPa O2 durante 48 h controlaron de manera eficaz las podredumbres verde y azul tras 7 días de incubación a 20ºC, pero el control de las dos podredumbres descendió tras 15 días (Capítulo 4). En almacenamiento en frío, tras 14, 28 y 42 días, la incidencia de moho verde en mandarinas 'Clemenules' y 'Ortanique' tratadas con baños con SP y 30kPa O2 durante 48h se redujo en un 100, 96 y 68%, y 100, 97 y 79%, respectivamente. De nuevo, una fuerte sinergia se observó entre los tratamientos (Capítulo 5). Las podredumbres verde y azul se controlaron eficazmente mediante la fumigación de limones y naranjas durante 6 h a 22ºC con dos dosis de 3000 ¿L L-1 amoniaco, inyectadas al inicio del tratamiento y 2 h después (Capítulo 6). El tratamiento con amoniaco controló una cepa de P. digitatum resistente a IMZ. Cuando la fruta se bañó en 10 o 30 mg L-1 IMZ (un 10% de la dosis comercial) antes de la fumigación con amoniaco, una sola aplicación con 1500 ¿L L-1 amoniaco fue suficiente para controlar las dos podredumbres, y el incremento en la eficacia fue aditivo o sinérgico. Todos estos tratamientos, a diferentes niveles, podrían sustituir a los fungicidas de síntesis o aumentar la eficacia de los tratamientos con IMZ en el manejo poscosecha de los cítricos. El desarrollo de las podredumbres verde y azul en las especies y variedades de cítricos más importantes comercialmente se evaluó durante cuatro campañas consecutivas y se relacionó con los parámetros de calidad de la fruta (Capítulo 7). La susceptibilidad de los cultivares en orden creciente fue Nova, Sanguinelli, Ortanique, Lanelate, Navelate, Fortune, Clemenules, Valencia, W. Navel, Oronules, Clemenpons, Marisol, Salustiana, Hernandina, y Nadorcott. Las características de la corteza fueron los parámetros de calidad / [CAT] Els cítrics (Citrus spp. fam. Rutaceae) son la fruita més consumida a nivell mundial i es cultiven en un centenar de països. Durant la poscollita, la major part de les pèrdues es deuen a malalties fúngiques, que durant dècades s'han controlat mitjançant tractaments amb fungicides de síntesi. No obstant, l'ús d'aquestes pràctiques està contínuament més restringit per part dels distribuïdors y cadenes de supermercats, que redueixen el Límit Màxim de Residus (LMR) a un terç del permès per la legislació o inclús prohibeixen l'ús d'alguns fungicides. Açò ha provocat la minora de l'eficàcia dels tractaments poscollita i el desenvolupament de soques dels patògens resistents als fungicides. Es necessari per lo tant trobar i implementar alternatives per a substituir o combinar l'ús de fungicides de síntesi. L'objectiu d'aquest treball ha sigut avaluar tractaments alternatius contra les podridures verda i blava, causades per Penicillium digitatum (Pers.: Fr.) Sacc. i Penicillium italicum Wehmer, respectivament. Additius alimentaris i substàncies GRAS es provaren en test in vivo preliminars contra les podridures verda i blava. El benzoat sòdic (BS; Capítol 1) i el sorbat potàsic (SP; Capítol 2) foren els més eficaços. Solucions calentes de BS combinades amb baixes dosis d'imazalil (IMZ) foren sinèrgiques. Esta combinació va reduir l'incidència de les podridures verda i blava en quasi el 100% en taronges 'Valencia Late' després de 8 setmanes a 5°C i 7 dies a 20°C. En assajos semicomercials mandarines 'Marisol', la combinació SP+IMZ a 20°C va permetre una baixada significativa de la dosis de IMZ sense perdre eficàcia contra la podridura verda. Un nou mètode colorimètric que inclou l'extracció del SP de la fruita macerada, seguit d'una reacció amb àcid 2-tiobabitúric (Capítol 3) mostrà que en taronges tractades amb SP conservades a 15°C, els residus descendiren ràpidament al inici i lentament mes tard, fins que deixaren de descendir després de 6 dies. Un doble rentat ràpid amb aigua corrent immediatament després de d'immersió de llimones en SP al 2% (p/v), eliminà més del 90% del residu de SP. Els xocs gasosos a 33ºC i 15kPa CO2 durant 24 h o 30 kPa O2 durant 48 h controlaren de manera eficaç les podridures verda i blava després de 7 dies d'incubació a 20ºC, però el control de les dos podridures descendí després de 15 dies (Capítol 4). La combinació de banys amb SP i xocs gasosos mostrà un efecte sinèrgic, que mantingué l'eficàcia dels tractaments combinats durant 15 dies. En conservacions en fred, després de 14, 28 i 42 dies, d'incidència de podridura verda en mandarines 'Clemenules' i 'Ortanique' tractades en banys amb SP i 30kPa O2 durant 48h es reduí en un 100, 96 i 68%, i 100, 97 i 79%, respectivament. De nou, una forta sinergia s'observà entre els tractaments (Capítol 5). Les podridures verda i blava es controlaren eficaçment mitjançant la fumigació de llimones i taronges durant 6 h a 22ºC amb dos dosis de 3000 ¿L L-1 amoníac, injectades al inici del tractament i 2 h després (Capítol 6). El tractament amb amoníac controlà una soca de P. digitatum amb un alt nivell de resistència a IMZ. Tots estos tractaments, a diferents nivells, podrien substituir als fungicides de síntesis o augmentar l'eficàcia dels tractaments amb IMZ en el maneig poscollita dels cítrics. El desenvolupament de les podridures verda i blava en les especies y varietats de cítrics més importants comercialment s'avaluà durant quatre campanyes consecutives i es relacionà amb els paràmetres de qualitat de la fruita (Capítol 7). La susceptibilitat dels distints cultivars en ordre creixent fon Nova, Sanguinelli, Ortanique, Lanelate, Navelate, Fortune, Clemenules, Valencia, W. Navel, Oronules, Clemenpons, Marisol, Salustiana, Hernandina, i Nadorcott. Les característiques de la pell foren els paràmetres de qualitat més influents en la susceptibilitat dels cítrics a les pod / Montesinos Herrero, CI. (2016). Evaluation of alternatives to synthetic fungicides to control citrus postharvest diseases [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63662 / TESIS

Philosophiae Doctor - PhD / Fusarium verticil/ioides (Sacc) Nirenberg a common phytopathogen of maize and maize-based products produces fumonisin B (FB) mycotoxins that have been related to several diseases such as equine leukoencephalomalacia (ELEM), porcine pulmonary edema (PPE), liver toxicity in several animals and esophageal and liver cancer in humans. In one of our studies we hypothesize that aqueous extracts of indigenous South African wild garlic species (Tulbaghia violacea, T. alliacea and T. simmleri) may enhance the efficacy of the fungicides, SporekilPu, Thiram, Itraconazole and Fluconazole against F. verticil/ioides (MRC 826). Data analysis from in vitro results indicates that for the 16 different mixtures of each plant extract and fungicide combination, several significantly (P<O.05) higher growth inhibition responses were produced. More synergistic interactions were observed for the combinations of sporekill with T. violacea (62%) and T. alliacea (75%) than for T. simmleri (25%) .. Mixtures between the azole fungicides and T. simmleri produced 94 % synergistic interactions. Combination of fungicides and plant compounds offers the opportunity to find synergistic mixtures and may validate disease control strategies with increased biological activity and low dose rate application. Modulation studies of hepatic drug metabolizing enzymes and oxidative properties of AI/ium sativum, Tulbaghia violacea and T. alliacea in male Fischer rats were also evaluated. Due to its complex phytochemical composition a battery of assays were used to evaluate antioxidant potential. The extracts exhibited no adverse effects in the liver and kidneys of the rats. Total plasma iron was not affected showing no evidence for iron catalyzed lipid peroxidation. An increase was noted in hepatic ORAC values for rats consuming T. violacea and T. al/iacea. However, no correlation was observed between the phenolic intake by the rats and the increased hepatic ORAC levels. In this study, pre-treatment with aqueous extracts of T. violacea, T. al/iacea and A. sativum resulted in a significant elevation in GSH levels, induction of GST -IJ and UDP-GT and modulation of CAT and SOD. This modulated oxidative status and phase II drug metabolizing enzymes in the liver may protect the liver against the adverse effects related to oxidative damage and mutagenesis. The chemoprotective properties of crude aqueous extracts of A. sativum, T. violacea and T. alliacea were investigated on preneoplastic foci formation promoted by culture material of F. verticil/ioides MRC 826 utilizing diethylnitrosamine (DEN) as cancer initiator. Clinical chemical parameters related to liver and kidney function and decreased body weight gain suggesting that severe, acute liver injury had been induced in the positive control (DEN-eMF) rats, while the levels were mostly reduced by the garlic treatments. This study further indicates that T. alliaceae (2 % w/v) and A. sativum (1% w/v) treatment suppressed GST-P+ foci formation with the modulation of GST-0 phase II detoxification enzymes, as well as the antioxidant enzyme, SOD (T. alliaceae) and decreased GSH levels as being possible mechanisms of protection. These results provide new evidence showing the modulation of phase II drug metabolizing enzymes and the oxidative status in the liver of rats by the wild garlic species as well as A. sativum.

Thesis (MScAgric)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Phaeomoniella chlamydospora, Eutypa lata, Phomopsis, Phaeoacremonium, and Botryosphaeria spp. are important trunk disease pathogens that cause premature decline and dieback of grapevine. Previous research has focused primarily on wine grapes and the incidence and symptomatology of these pathogens on table grapes were largely unknown. A survey was therefore conducted to determine the status and distribution of these pathogens and associated symptoms in climatically diverse table grape growing regions. Fifteen farms were identified in the winter rainfall (De Doorns, Paarl and Trawal) and summer rainfall (Upington and Groblersdal) areas. Samples were taken in July and August 2004 from Dan-ben-Hannah vineyards that were 8 years and older. Distal ends of arms were removed from 20 randomly selected plants in each vineyard. These sections were dissected and isolations were made from each of the various symptom types observed: brown or black vascular streaking, brown internal necrosis, wedge-shaped necrosis, watery necrosis, esca-like brown and yellow soft wood rot, as well as asymptomatic wood. Fungal isolates were identified using molecular and morphological techniques. Pa. chlamydospora was most frequently isolated (46.0%), followed by Phaeoacremonium aleophilum (10.0%), Phomopsis viticola (3.0%), Botryosphaeria obtusa (3.0%), B. rhodina (2.2%), B. parva (2.0%), Fusicoccum vitifusiforme (0.6%), B. australis, B. dothidea and an undescribed Diplodia sp. (0.2% each), while E. lata was not found. Most of these pathogens were isolated from a variety of symptom types, indicating that disease diagnosis can not be based on symptomatology alone. Pa. chlamydospora was isolated from all areas sampled, although most frequently from the winter rainfall region. Pm. aleophilum was found predominantly in Paarl, while P. viticola only occurred in this area. Although B. obtusa was not isolated from samples taken in De Doorns and Groblersdal, it was the most commonly isolated Botryosphaeria sp., being isolated from Upington, Paarl and Trawal. B. rhodina occurred only in Groblersdal and B. parva in Paarl, Trawal and Groblersdal, while B. australis was isolated from Paarl only. The rest of the isolates (33%) consisted of sterile cultures, Exochalara, Cephalosporium, Wangiella, Scytalidium, Penicillium spp. and two unidentified basidiomycetes, which were isolated from five samples with yellow esca-like symptoms from the Paarl area. These findings clearly illustrate that grapevine trunk diseases are caused by a complex of fungal pathogens, which has serious implications for disease diagnosis and management. Protection of wounds against infection by any of these trunk disease pathogens is the most efficient and cost-effective means to prevent grapevine trunk diseases. However, previous research on the effectiveness of chemical pruning wound protectants has mostly focused on the control of Eutypa dieback only. Fungicide sensitivity studies have been conducted for Pa. chlamydospora, P. viticola and Eutypa lata, but no such studies have been conducted for the pathogenic Botryosphaeria species from grapevine in South Africa. Ten fungicides were therefore tested in vitro for their efficacy on mycelial inhibition of the four most common and/or pathogenic Botryosphaeria species in South Africa, B. australis, B. obtusa, B. parva and B. rhodina. Iprodione, pyrimethanil, copper ammonium acetate, kresoxim-methyl and boscalid were ineffective in inhibiting the mycelial growth at the highest concentration tested (5 μg/ml; 20 μg/ml for copper ammonium acetate). Benomyl, tebuconazole, prochloraz manganese chloride and flusilazole were the most effective fungicides with EC50 values for the different species ranging from 0.36-0.55, 0.07-0.17, 0.07-1.15 and 0.04-0.36 μg/ml, respectively. These fungicides, except prochloraz manganese chloride, are registered on grapes in South Africa and were also reported to be effective against Pa. chlamydospora, P. viticola and E. lata. Results from bioassays on 1-year-old Chenin Blanc grapevine shoots indicated that benomyl, tebuconazole and prochloraz manganese chloride were most effective in limiting lesion length in pruning wounds that were inoculated with the Botryosphaeria spp after fungicide treatment. The bioassay findings were, however, inconclusive due to low and varied re-isolation data of the inoculated lesions. Benomyl, tebuconazole, prochloraz manganese chloride and flusilazole can nonetheless be identified as fungicides to be evaluated as pruning wound protectants in additional bioassays and vineyard trials against Botryosphaeria spp. as well as the other grapevine trunk disease pathogens. / AFRIKAANSE OPSOMMING: Phaeomoniella chlamydospora, Eutypa lata, Phomopsis, Phaeoacremonium, en Botryosphaeria spesies is die mees belangrikste stamsiekte patogene wat agteruitgang en vroeë terugsterwing van wingerd veroorsaak. Voorafgaande navorsing het hoofsaaklik gefokus op wyndruiwe en die voorkoms en simptomatologie van hierdie patogene op tafeldruiwe is dus grootliks onbekend. ‘n Opname is gevolglik gedoen in verskillende klimaaatsareas waar tafeldruiwe verbou word om die voorkoms en verspreiding, asook die simptome geassosieer met hierdie patogene, te bepaal. Vyftien plase is geïdentifiseer in die winter- (De Doorns, Paarl en Trawal) en somer-reënval (Upington en Groblersdal) streke. Wingerde (8 jaar en ouer) met die kultivar Dan-ben-Hannah is gekies vir opname en monsters is gedurende Julie en Augustus 2004 geneem. Die distale deel van ‘n arm is verwyder vanaf 20 lukraak gekose plante in elke wingerd. Hierdie dele is ontleed en isolasies is gemaak vanuit elke simptoomtipe wat beskryf is, naamlik bruin en swart vaskulêre verkleuring, bruin interne nekrose, wig-vormige nekrose, waterige nekrose, esca-geassosieerde bruin en geel sagte houtverrotting en asimptomatiese hout. Identifikasie van die swamagtige isolate is gedoen op grond van morfologiese eienskappe en molekulêre tegnieke. Pa. chlamydospora is die meeste geïsoleer (46.0%), gevolg deur Phaeoacremonium aleophilum (10.0%), Phomopsis viticola (3.0%), Botryosphaeria obtusa (3.0%), B. rhodina (2.2%), B. parva (2.0%), Fusicoccum vitifusiforme (0.6%), B. australis, B. dothidea en ‘n onbeskryfde Diplodia sp. (0.2% elk), terwyl E. lata nie geïsoleer is nie. Hierdie patogene is elk geïsoleer vanuit ‘n verskeidenheid simptoomtipes, wat daarop dui dat siektediagnose nie alleenlik op simptomatologie gebaseer kan word nie. Pa. chlamydospora is geïsoleer vanuit al die gebiede, alhoewel die patogeen opmerklik meer voorgekom het in die winter-reënval area. Pm. aleophilum het hoofsaaklik voorgekom in Paarl, terwyl P. viticola slegs in hierdie area voorgekom het. Alhoewel B. obtusa nie voorgekom het in die De Doorns en Groblersdal areas nie, was dit die mees algemeen geïsoleerde Botryosphaeria sp. en het in Upington, Paarl en Trawal voorgekom. B. rhodina het slegs in Groblersdal voorgekom, B. parva in Paarl, Groblersdal en Trawal en B. australis het slegs in Paarl voorgekom. Die res van die isolate (33%) het bestaan uit steriele kulture, Exochalara, Cephalosporium, Wangiella, Scytalidium, en Penicillium spesies asook twee onbekende basidiomycete isolate, geïsoleer vanuit vyf monsters met geel eska-geassosieerde simptome vanuit die Paarl area. Hierdie resultate illustreer dus die feit dat wingerdstamsiektes deur ‘n kompleks van swampatogene veroorsaak word, wat belangrike implikasies het vir die bestuur en diagnose van hierdie siektes. Wondbeskerming teen infeksie van enige van hierdie stamsiekte patogene is die mees doeltreffende en koste-effektiewe manier om wingerdstamsiektes te voorkom. Vorige navorsing aangaande die effektiwiteit van chemiese wondbeskermingsmiddels het egter slegs gefokus op die beheer van Eutypa terugsterwing. In vitro swamdoder sensitiwiteitstoetse is gedoen vir Pa. chlamydospora, P. viticola en Eutypa lata, maar geen studies is al gedoen ten opsigte van die patogeniese Botryosphaeria spesies op wingerd in Suid-Afrika nie. Tien swamdoders is dus getoets vir inhibisie van in vitro miseliumgroei van die vier mees algemene en/of patogeniese Botryosphaeria spesies wat in Suid-Afrika voorkom, naamlik B. australis, B. obtusa, B. parva en B. rhodina. Iprodione, pyrimethanil, koper ammonium asetaat, kresoxim-metiel en boscalid was oneffektief by die hoogste konsentrasies getoets (5 μg/ml; 20 μg/ml vir koper ammonium asetaat). Benomyl, tebuconasool, prochloraz mangaan chloried en flusilasool was die mees effektiewe swamdoders met EC50 waardes tussen 0.36-0.55, 0.07-0.17, 0.07-1.15 en 0.04-0.36 μg/ml, onderskeidelik vir die verskillende spesies. Hierdie fungisiedes, behalwe prochloraz mangaan chloried, is geregistreer op druiwe in Suid-Afrika en is ook effektief gevind teenoor Pa. chlamydospora, P. viticola en E. lata. Resultate van biotoetse op 1-jaar-oue Chenin Blanc wingerd lote het getoon dat benomyl, tebuconasool en prochloraz mangaan chloried die effektiefste was om die lengte van letsels in snoeiwonde, geinokuleer met Botryosphaeria spesies na die aanwending van swamdoder behandelings, te verminder. Die bevindinge was egter onbeslis as gevolg van die lae en variërende her-isolerings data. Benomyl, tebuconasool, prochloraz mangaan chloried en flusilasool kan egter geïdentifiseer word as swamdoders wat verder geevalueer kan word as snoeiwond beskermingsmiddels teen Botryosphaeria spesies asook ander wingerd stamsiekte patogene in verdere biotoetse en wingerdproewe.

A ocorrência das doenças de final de ciclo causadas pelos fungos Septoria glycines e Cercospora kikuchii é facilmente observada no campo. Entretanto, são necessárias informações precisas sobre a quantificação de danos e perdas na produtividade, bem como, a definição da melhor época para aplicação de fungicidas. A falta de um método padrão de quantificação visual pode levar a estimativas imprecisas da severidade das mesmas, induzindo a conclusões erradas. Com os objetivos de elaborar e validar uma escala diagramática para a quantificação das doenças de final de ciclo da soja, avaliar o efeito dessas doenças sobre a produtividade, identificar o melhor estádio fenológico da cultura para o controle dessas doenças, verificar a relação entre a severidade dessas doenças e a produtividade e avaliar os efeitos das mesmas sobre a duração e absorção da área foliar sadia das plantas de soja, foram instalados experimentos na Fazenda Areão (ESALQ/USP), localizada em Piracicaba - SP. Utilizou-se o cultivar de soja MG/BR - 46 (Conquista), considerado suscetível a essas doenças, adotando-se o delineamento experimental de blocos ao acaso, no esquema fatorial 2 x 3 (dois fungicidas: benomyl e tebuconazole e três momentos fenológicos de pulverização: R4, R5.3 e R6) com três tratamentos adicionais (testemunha, pulverização quinzenal de benomyl e pulverização quinzenal de tebuconazole), repetidos três vezes. Determinou-se a severidade dessas doenças; o número de vagens e de sementes por planta; a massa de 1000 sementes e a produtividade. Para quantificação da severidade dessas doenças foi elaborada uma escala diagramática a partir de folhas coletadas em campo, apresentando diferentes níveis de severidade. A área de cada folha e sua correspondente severidade foram determinadas e, seguindo-se a "Lei do Estímulo de Weber-Fechner", elaborou-se a escala com os níveis de severidade de doença: 2,4; 15,2; 25,9; 40,5 e 66,6%. A validação foi realizada por nove avaliadores, sem experiência na avaliação das doenças de final de ciclo, os quais estimaram a severidade de 30 folíolos de soja com sintomas destas doenças. A precisão das avaliações variou de acordo com o avaliador (0,84<R 2 <0,65), bem como a acurácia (0,00<a<3,40; 0,90<b<1,29), não ocorrendo erro sistemático na superestimativa ou subestimativa da doença entre os avaliadores. Com base nos resultados obtidos em três safras agrícolas consecutivas (1999/2000, 2000/2001 e 2001/2002), pôde-se concluir que: a) a escala diagramática desenvolvida é adequada para a quantificação da severidade das doenças de final de ciclo em soja; b) as doenças de final de ciclo, quando em severidade inferior a 10%, não afetam o número de vagens e sementes produzidos por planta mas, causam redução na produtividade da soja; c) os fungicidas benomyl e tebuconazole podem ser utilizados no controle dessas doenças; d) não foi possível determinar a época fenológica mais adequada para a pulverização de fungicidas, que proporcionasse aumentos na produtividade da soja; e) em severidade dessas doenças abaixo de 10%, não existe relação entre esta variável, a massa de 1000 sementes e a produtividade; f) a absorção da área foliar sadia é a variável que melhor expressa a relação entre a severidade dessas doenças e a produtividade da soja. / The occurrence of late season leaf diseases caused by the fungus Septoria glycines and Cercospora kikuchii is easily identified in field. However, there is a need of precise information to quantify the damage and yield losses as well as to define the best occasions for fungicide applications. The lack of a standardized visual method may lead to inaccurate estimates of their severity, inducing inexact conclusions. With the purposes: to elaborate and validate a diagrammatic scale to assess late season leaf soybean diseases; to evaluate the effect of theses diseases on yield; to identify the best soybean growth stages for chemical control; to verify the relation between severity of theses diseases and yield and to evaluate the effect of theses diseases on healthy leaf area duration and healthy leaf area absorption, were installed field experiments at Fazenda Areão (ESALQ/USP), in Piracicaba - SP. The soybean cultivar MG/BR - 46 (Conquista), susceptible to both diseases was sown in a complete randomized blocks design in factorial 2 x 3 (two fungicides: benomyl and tebuconazole and three application stages: R4, R5.3 e R6) and three extra treatments (control without application, fortnightly application of benomyl and fortnightly application of tebuconazole), at three replications. The severity, the pod number per plant, the seed number per pod, the mass of 1,000 seed and yield were determined. To quantify the severity of these diseases it was elaborated a diagrammatic scale, from leaves collected in the field presenting different levels of severity. The area of each leaf and its correspondent severity were determined, and following the "Stimulus Law by Weber-Fechner" a scale was elaborated with the severity levels: 2.4, 15.2, 25.9, 40.5 and 66.6%. The validation was carried out by nine appraisers, without previous practice in assessing late season leaf diseases, who estimate the severity on 30 leaflets of soybean with disease symptoms. The evaluation precision varied according to the appraiser (0.84<R 2 <0.65), as well as the accuracy (0.00<a<3.40; 0.90<b<1.29), do not occurring systematic mistakes in the super or underestimation of the disease among the appraisers. Based on the obtained results in three consecutive crop seasons (1999/2000, 2000/2001 e 2001/2002), it was possible to conclude that: a) the developed diagrammatic scale is appropriate to quantify the late season leaf diseases severity of soybean; b) the late season leaf diseases, when in severity below 10%, do not affect the number of pod and seeds per plant but cause reduction of yield; c) the fungicides benomyl and tebuconazole may be used to control these diseases; d) it was not possible to determine the most appropriate growth stage for fungicide application, which result in yield gain; e) under severity below 10% there are not relation between this variable and the mass of 1,000 seed and yield; f) the healthy leaf area absorption is the variable which most express the relation between the severity of this diseases and the soybean yield.

O Brasil é um dos principais países produtores de abacate. A competitividade do país no comércio internacional desta fruta demanda a minimização de danos pós-colheita, especialmente os causados pela antracnose. Este trabalho objetivou: (i) identificar e quantificar os danos pós-colheita em abacates Fuerte e Hass; (ii) identificar e caracterizar isolados de Colletotrichum do abacateiro, comparando-os com isolados de outras frutíferas; (iii) avaliar o efeito de temperatura e período de molhamento sobre a germinação de conídios e formação de apressórios, bem como, sobre a infecção e colonização de Colletotrichum gloeosporioides em abacates; (iv) avaliar o efeito de fungicidas e sanitizantes no controle da antracnose do abacateiro em pós-colheita. As incidências da antracnose e de outros danos póscolheita foram avaliadas periodicamente em abacates amostrados em três etapas do beneficiamento em packinghouse e revelaram que a antracnose foi a principal doença póscolheita, com incidências média de 45,7% para o abacate Fuerte e 68,7% para Hass. Identificação, caracterização e análise comparativa foram realizadas para 93 isolados obtidos de abacate, manga, maracujá e pêssego, por meio do aspecto da colônia e taxa de crescimento em diferentes temperaturas, formato e dimensões dos conídios, análise molecular (PCR com oligonucleotídeos espécie-específicos e análise de sequências de nucleotídeos das regiões ITS e -tubulina), patogenicidade e atividade enzimática (amilase, catalase, celulase, lacase, lípase, pectinase e proteinase). Todos os isolados de abacate e manga, e alguns isolados de pêssego e maracujá foram identificados como C. gloeosporioides. As espécies C. acutatum e C. boninense foram detectadas em pêssego e maracujá, respectivamente. A análise filogenética associada a algumas características morfo-culturais permitiu a separação das espécies e revelou diferenças intra-específicas entre os isolados de C. gloeosporioides, de acordo com o hospedeiro de origem. Os isolados de manga compuseram um grupo distinto dentro da espécie. Entretanto, independente do hospedeiro de origem, as três espécies de Colletotrichum promoveram infecções cruzadas nos quatro hospedeiros avaliados, indicando a ausência de especificidade patogênica. Para todas as características avaliadas houve alta variabilidade entre os isolados. Germinação de esporos e formação de apressórios de C. gloeosporioides sobre abacates Fuerte incubados a 5, 10, 15, 20, 25, 30, 35 e 40ºC com período de molhamento de 3, 6, 12, 24h revelou que o fungo pode explorar ampla faixa de temperatura, germinando e formando apressórios entre 10 e 35ºC, com temperatura ótima de 23,4ºC e 24,0ºC, respectivamente. Aumento no período de molhamento promoveu maiores percentagens de esporos germinados e formação de apressórios. Os efeitos da temperatura (10, 15, 20, 25, 30ºC) e períodos de molhamento (6, 12, 24h) na infecção e colonização por esta espécie foram avaliados em frutos de Hass e Fuerte, inoculados com ferimento. Exceto a 10ºC, houve manifestação de sintomas em todas as temperaturas, com maiores lesões e taxas de progresso da doença a 30ºC. Para controle das doenças testou-se tratamento dos frutos por imersão em calda contendo azoxistrobina, cloreto de benzalcônio, dióxido de cloro, Ecolife®, hipoclorito de sódio, imazalil, procloraz e tiabendazol. Dentre esses, procloraz e imazalil foram os mais eficientes. / Brazil is one of the most important avocado producers in the world. However, to compete in the international avocado business it is necessary reduction of post-harvest damages, especially those caused by anthracnose. This work had the following objectives: (i) to identify and to quantify post-harvest damages in Fuerte and Hass avocados; (ii) to identify and to characterize the avocado isolates of Colletotrichum, comparing them with other fruit isolates; (iii) to evaluate the effect of temperature and wetness period in the conidia germination and appressoria formation, as well as in the infection and colonization of Colletotrichum gloeosporioides in avocado; (iv) to evaluate the post-harvest control of anthracnose in avocado using fungicides and sanitizers. Both the anthracnose incidence and other post-harvest damages were evaluated periodically using avocado samples collected at three steps in the packinghouse. It was revealed that anthracnose was the major factor of post-harvest damages, with average incidence of 45.7% in Fuerte and 68.7% in Hass. Identification, characterization and comparative analyses were performed with 93 isolates from avocado, mango, passion fruit and peach according to the colony aspect and growth rate in different temperatures, conidia shape and size, molecular analyses (species-specific PCR and sequencing of ITS and -tubulin genes), pathogenicity and enzymatic activity (amylase, catalase, cellulase, laccase, lipase, pectinase and proteinase). All of the avocado and mango isolates and some isolates from peach and passion fruit were identified as C. gloeosporioides. The species C. acutatum and C. boninense also were indentified in peach and passion fruit, respectively. Phylogenetic analyses performed with some morphological data allowed species differentiation and revealed intra-specific differences between C. gloeosporioies according to the original host. Mango isolates were grouped together into the C. gloesporioides clade. However, independently of the original host, these three Colletotrichum species showed to cross-infect the four evaluated hosts, suggesting lack of pathogenical specificity. There was high variability for all evaluated characteristic. For C. gloeosporioides, spores germination and appressoria formation on the surface of Fuerte avocado incubated under 5, 10, 15, 20, 25, 30, 35 and 40 ºC and wetness periods of 3, 6, 12 and 24 hours showed that this fungus could explore a wide range of temperature. Germination and appressoria formation were observed between 10 and 35 ºC, with optimal temperatures of 23.4 and 24.0 ºC, respectively. Both the germination and appressoria formation were higher with the increase in the wetness period. The effect of temperature (10, 15, 20, 25, 30 ºC) and the wetness period (6, 12, 24h) were evaluated on the infection and colonization of C. gloeosporioides in Fuerte and Hass avocado, which were wound-inoculated. Except at 10 ºC, all tested temperatures led to symptoms expression. The highest disease progress rate and lesion diameter were verified at 30 ºC. Fruit immersion on fungicides solution was tested to control post-harvest diseases using azoxystrobin, benzalkonium chloride, chlorine dioxide, Ecolife, sodium hypochloride, imazalil, procloraz and thiabendazol. Among these fungicides, prochloraz and imazalil were the most efficient in controlling post-harvest diseases in avocado.

Essa pesquisa buscou comparar as tecnologias transgênica (soja RR e manejo com glifosato) e convencional (soja e manejo convencionais) quanto à maior tolerância à ferrugem asiática (Phakopsora pachyrhizi) e obtenção de genótipos promissores para produtividade de grãos (PG) e tamanho das sementes (representado pelo peso de cem sementes, PCS). Foram avaliadas 200 progênies F2:5 e F2:6 oriundas de dois dialelos parciais 5 x 2, ambos com cinco genitores de alta produtividade de óleo (USP 70.108, USP 70.010, USP 70.113, USP 70.007 e USP 70.042) em cruzamentos com: (1) duas cultivares elites convencionais (BRS 133 e Conquista); (2) suas versões essencialmente derivadas transgênicas (BRS 245 RR e BRS Valiosa RR). Os experimentos envolveram: a) dois manejos com herbicidas, manejo convencional para soja convencional e manejo com glifosato para a soja RR; b) dois manejos de fungicidas, sendo um experimento com aplicações sucessivas de Opera & Nativo (O&N, para controle da ferrugem e das doenças de final de ciclo, DFC) e outro experimento com aplicações de Derosal para controle apenas das DFC. O efeito da ferrugem para cada genótipo foi expresso pela taxa de reação da ferrugem sobre a produtividade (FP) e o tamanho das sementes (FT), calculados pelas diferenças entre médias ajustadas de PG e PCS nos dois experimentos com fungicidas. As comparações foram feitas em análises de variância, testes de médias e de parâmetros de capacidade de combinação. O controle da ferrugem com fungicidas (O&N) resultou em maiores médias de PG e PCS. Houve grande variação entre os efeitos de capacidades geral e específica, com destaque dos genitores USP 70.108, USP 70.010 e BRS 133 para PG e FP. O genitor mais divergente e com dominância positiva para PG foi USP 70.042. As duas tecnologias foram numericamente semelhantes para tolerância à ferrugem (FP e FT). A tecnologia convencional apresentou a vantagem de ser estatisticamente mais produtiva (PG e PCS) do que a tecnologia transgênica. Por outro lado, a tecnologia transgênica tem a vantagem de ter uso mais fácil e menor custo de cultivo aos produtores. / This research aimed to compare the performance of transgenic (RR soybean and management with glyphosate) and conventional (conventional soybean and herbicides) technologies for tolerance to rust (Phakopsora pachyrhizi ) and obtaining promising genotypes for seed yield and size (represented by the weight of one hundred seeds, PCS). A total of 200 progenies were evaluated in F2:5 and F2:6 generations; these progenies were obtained in two partial diallel 5 x 2, both involving five parents with high oil yield (USP 70.108, USP 70.010, USP 70.113, USP 70.007 and USP 70.042) in crosses with: (1) two elites conventional cultivars (BRS 133 and Conquista); (2) their essentially derived transgenic versions (BRS 245 RR and BRS Valiosa RR). The experiments involved: a) two managements with herbicides: conventional management for conventional soybean and management based in glyphosate herbicide to RR soybean; b) two managements with fungicides: an experiment with successive applications of Opera & Native (O&N, fungicides that control rust and late season leaf diseases, DFC), and another experiment with Derosal applications (fungicide that controls only DFC). The effect of rust for each genotype was expressed by the rate of reaction to rust on seed yield (FP) and on seed size (FT) as calculated from the differences in seed yield (PG) and seed size (PCS) between adjusted means in the two experiments with different fungicides. The soybean genotypes were compared by analysis of variance, multiple comparisons and parameter estimation of combining ability. In general, the control of rust with fungicides (O&N) resulted in higher means of PG and PCS. There was great variation among the effects of general and specific combining abilities, with major outstanding of USP 70.108, USP 70.010, and BRS 133 parents for PG and FP. The parent USP 70.042 was the most divergent and showed positive dominance for PG. Both technologies were numerically similar for FP and FT. The conventional technology has the advantage to be statistically more productive (PG and PCS) than transgenic technology. However, the transgenic technology has the advantage to be easier to use and less expensive to soybean producers.

O objetivo desse estudo foi caracterizar e selecionar linhagens de soja, considerando sua reação à ferrugem asiática (FAS) e a produtividade de grãos (PG). O presente trabalho foi desenvolvido no Setor de Genética Aplicada às Espécies Autógamas, no Departamento de Genética da Escola Superior de Agricultura Luiz de Queiroz, localizada no município de Piracicaba, SP, Brasil. No ano agrícola 2004/2005 (A1), foram conduzidos três experimentos com fungicidas (impact, derosal e controle) com genótipos de ciclo médio (EGM) e três com genótipos tardios (EGT), totalizando seis experimentos delineados em blocos casualizados, com quatro repetições. As parcelas experimentais foram representadas por quatro fileiras de 5 m x 0,5 m, sendo que a área útil de 4 m2 constituiu-se pelas duas fileiras centrais, eliminando-se 0,5 m em cada extremidade da parcela. Os três experimentos, para cada ciclo, foram utilizados para possibilitar a caracterização dos genótipos quanto a RFA: (i) Experimento I: três aplicações de Impact (Flutriafol, Cheminova): fungicida eficiente para o controle das doenças de final de ciclo (DFC), incluindo-se a FAS; (ii) Experimento II: três aplicações de Derosal (Carbendazim, Bayer): fungicida eficiente para o controle das DFC, exceto a FAS; (iii) Experimento III: controle: sem aplicação de fungicidas. Os EGM envolveram duas testemunhas (BR-16 e IAS-5) e 12 linhagens de ciclo médio, selecionadas pelo diferencial positivo de 4% a 221% sobre a PG da melhor testemunha, na presença da FAS. Na seleção das linhagens experimentais utilizadas nesse trabalho, além do ciclo e da PG, também foi considerada a presença de ancestrais tolerantes a FAS em suas genealogias, que contribuiram como fontes de genes para resistência a FAS, com destaque para : FT-2, IAC PL1, TN#4 (Taiwan) e PI 230970 (Taiwan). Tal fato aumentou a probabilidade de se encontrar genótipos tolerantes (T) ou moderadamente resistentes (MR) dentre as linhagens avaliadas. Foram realizadas avaliações experimentais para FAS e PG. A FAS foi avaliada através de três notas (NF1, NF2 e NF3), usando-se uma escala diagramática, com notas variando de 1 (0,2% de área doente) a 9 (78,5% de área doente ou mais). A PG de cada linhagem foi estimada por meio da pesagem das parcelas. A linhagem de ciclo médio USP 97-08.135 mostrou-se MR. Já as linhagens BULK USP 01-28, USP 04-18.029 e USP 04-18.074 mostraramse T a FAS. Os EGT também envolveram duas testemunhas (FT-2000 e Conquista) e 12 linhagens com diferencial positivo de PG de 87% a 177%. As linhagens tardias USP 191-102-03, USP 191-103-12, USP 191-108-05, USP 98-13.035, USP 98-13.049 e USP 98-13.102 foram classificadas como MR e as demais linhagens como não-tolerantes (NT) ou suscetíveis (S). Dentre as linhagens testadas no A1 foram selecionadas 12, para compor os experimentos do ano agrícola 2005/2006 (A2) e mais as duas testemunhas de ciclo médio e as duas tardias. Em A2 todas as linhagens e testemunhas foram classificadas como NT ou S, porém, a linhagem que mais se aproximou do comportamento T foi USP 97-08.135. / This research aimed to characterize and select soybean genotypes, considering their reaction to Asian soybean rust (FAS) and grain yield (PG). This work was developed in the Sector of Applied Genetics to Self-Pollinated Crops, Department of Genetics, Faculty of Agriculture Luiz de Queiroz, University of São Paulo located in Piracicaba city, State of São Paulo, Brazil. In 2004/2005 agricultural year (A1) were conducted three experiments with intermediate cycle genotypes (EGM) and three with late cycle genotypes (EGT) outlined in random blocks, with four repetitions. Then, in A1 were conducted six experiments in the total (Impact, Derosal and Control for each cycle). The plots were represented by four rows of 5 m x 0,5 m. The useful plot (4 m2) were the two central rows, eliminating up 0,5 m at each end of the plot. Were used three experiments for the genotypes characterization about their reaction to rust in each cycle: (i) Experiment I: three applications of Impact (Flutriafol, Cheminova): effective to control the end of cycle diseases (DFC), including FAS; (ii) Experiment II: three applications of Derosal (Carbendazim, Bayer): effective to control the DFC, except the FAS; (iii) Experiment III: control: no application of fungicides. The EGM involved two soybean cultivars (BR-16 and IAS- 5) and 12 lines selected by the positive differential of 4% to 221% on the PG of the best, in the presence of rust. In the lines selection used in this experimental work, beyond the cycle and PG, was also considered the presence in their pedigrees of a tolerant ancestral to the FAS, which could contribute as a source of genes for resistance to FAS, with emphasis on: FT - 2, IAC - PL1, TN # 4 (Taiwan) and PI 230.970 (Taiwan). This fact increased the likelihood of finding tolerant or resistant genotypes in that evaluated. Were carried out evaluations to reaction to FAS and PG. The reaction to FAS was evaluated through three assessments (NF1, NF2 and NF3), with a diagrammatic scale, with visual notes ranging from 1 (0,2% of the foliar area affected) to 9 (78,5% of the foliar area affected). The PG of each line was estimated by the weight of the plots. It was observed moderate resistance (MR) to FAS on the line USP 97-08.135 and tolerance (T) to FAS on the lines BULK USP 01-28, USP 04-18.029 e USP 04-18.074 in the intermediate genotypes. The EGT also involved two cultivars (FT-2000 and Conquista) and 12 lines with a PG positive differential of 87% to 177%. The late cycle lines USP 191-102-03, USP 191-103-12, USP 191-108-05, USP 98-13.035, USP 98-13.049 e USP 98-13.102 were classified as MR and the others as no-tolerants or susceptible. Were selected 12 lines among the lines tested in A1 to compose the experiments of the agricultural year 2005/2006 (A2) and over the two early cultivars and the two late cultivars. The line that stood out more about the reaction to FAS was USP 97- 08.135.

Made available in DSpace on 2017-07-25T19:30:45Z (GMT). No. of bitstreams: 1 Carlos Rafael Wutzki.pdf: 1863942 bytes, checksum: 92b287f4925fa1855b1c0d218fc2bb5e (MD5) Previous issue date: 2014-02-07 / The white mold of soybean, caused by Sclerotinia sclerotiorum, is causing great damage to the soybean crop in Brazil. It is a polyphagous fungus hard to control because it produces resistance structures called sclerotia, which can remain viable in the soil for several years. Aiming its control, various management strategies should be used as the control with alternative substances, biological control agents and fungicides. Thus, nine experiments were conducted in naturally infested areas by white mold in 2011/12 season in the counties of Arapoti/PR, Mauá-da-Serra/PR and Pinhão/PR, with an experiment of alternated control, a biological control and one of chemical control conducted at each site. The variables analyzed were incidence, severity, yield and numbers of sclerotia produced. The objective of the experiments of alternative control was to assess different alternative substances, foliar sprayed, isolated or combined with the fungicide fluazinam, for control of white mold in soybean. The alternative substances applied were sodium dichloroisocyanurate, benzalkonium chloride, pyrolysis extract, sodium hypochlorite, cobalt + molybdenum, sucrose, sodium bicarbonate and acibenzolar-S-methyl. As conclusions, it was observed that alternative substances applied in combination with the fungicide fluazinam provided lower severity of white mold in soybeans on the experiment conducted in Pinhão – PR, and fungicide fluazinam applied alone or in combination with alternative substances was effective in control of white mold in soybeans in locations with high incidence of the disease. The objective of the experiments of biological control was to evaluate different biological control agents sprayed foliar compared to the untreated control and the fungicide Fluazinam for control of white mold in soybean. The biological control agents used were: Thichoderma harzianum SC; Thichoderma asperellum EC; Thichoderma asperellum WG; Coniothyrium minitans and Bacillus subtilis. As conclusion, the biological control agents were not effective in controlling white mold of soybean in the conditions that were tested, and the fungicide fluazinam demonstrated lower incidence and severity of disease and higher yield of soybean when applied in areas with high potential inoculum. Finally, the objective of the experiments of chemical control was to verify the efficiency of the control of white mold in soybeans with the use of fungicides applied alone, in rotation, at different growth stages and in a mixture of two active ingredients. The fungicides used were carbendazim, thiophanate methyl, procymidone and fluazinam. As conclusion, the use of fungicides were effective in controlling the incidence and production of sclerotia of S. sclerotiorum in soybean, especially the combinations that had two or more applications of the active ingredient Fluazinam. / O mofo branco da soja, causada pelo fungo Sclerotinia sclerotiorum, vem causando grandes danos na cultura da soja no Brasil. Trata-se de um fungo polífago de difícil controle, pois produz estruturas de resistência denominadas escleródios, que podem permanecer viáveis no solo por vários anos. Visando seu controle, várias estratégias de manejo devem ser utilizadas, como o controle com substâncias alternativas, agentes de controle biológico e fungicidas. Diante disso, foram conduzidos nove experimentos em áreas naturalmente infestadas pelo mofo branco na safra 2011/12 nos municípios de Arapoti/PR, Mauá-da-Serra/PR e Pinhão/PR, sendo um experimento de controle alternativo, um de controle biológico e um de controle químico conduzidos em cada local. As variáveis analisadas foram incidência, severidade, rendimento e o número de escleródios produzidos. O objetivo dos experimentos de controle alternativo foi avaliar diferentes substâncias alternativas pulverizadas via foliar, isoladamente ou em combinação com o fungicida fluazinam para o controle do mofo branco em soja. Nos experimentos de controle alternativo as substâncias utilizadas foram: dicloroisocianurato de sódio, cloreto de benzalcônio, extrato pirolenhoso, hipoclorito de sódio, cobalto + molibdênio, sacarose, bicarbonato de sódio e acibenzolar-S-metil. Concluiu-se que as substâncias alternativas aplicadas em associação com o fungicida fluazinam proporcionaram menor severidade do mofo branco na cultura da soja no experimento conduzido em Pinhão – PR e a aplicação do fungicida fluazinam isolado ou em associação com as substâncias alternativas foi eficiente no controle do mofo branco na cultura da soja nos locais com alta incidência da doença. O objetivo dos experimentos de controle biológico foi avaliar diferentes agentes de controle biológico pulverizados via foliar em comparação ao tratamento controle e ao fungicida fluazinam para o controle do mofo branco em soja. Os agentes de controle biológico utilizados foram: Thichoderma harzianum SC; Thichoderma asperellum EC; Thichoderma asperellum WG; Bacillus subtilis e Coniothyrium minitans. Conclui-se que os agentes de controle biológico não foram eficazes no controle do mofo branco da soja nas condições em que foram testados e que o fungicida fluazinam proporcionou menor incidência e severidade do doença quando aplicado em áreas com elevado potencial de inóculo. E finalmente, o objetivo dos experimentos de controle químico foi verificar a eficiência de controle do mofo branco na soja com o uso de diferentes fungicidas aplicados isoladamente, em rotação, em diferentes estádios fenológicos e em mistura de dois princípios ativos. Os fungicidas utilizados foram carbendazim, tiofanato metílico, fluazinam e procimidona. Concluiu-se que os fungicidas testados proporcionaram menores níveis de incidência e menor produção de escleródios, principalmente as combinações que possuíam duas ou mais aplicações do princípio ativo fluazinam.

Made available in DSpace on 2017-07-25T19:31:04Z (GMT). No. of bitstreams: 1 Emir Artaban.pdf: 2119391 bytes, checksum: b2cccd3c6d1b3f7b9dd64de986c4ad8c (MD5) Previous issue date: 2009-11-27 / This work presents the results of two experiments that were carried out with the objective of evaluating the of fungicides in the control of foliar diseases on onion crops. Also, it was verified the influence of hose fungicides sprayed over the leaves at the post-planting up to the pre-harvest phase in the reduction of the post-harvest diseases. In the bulb production trial the cultivars Vitória, Bola Precoce and Montana were avaluated. The experiment was designed with10tratments such as: Control (no spray); 0,5 L/ha of Difenoconazol; 1,0 L/ha of Tebuconazol; 0,75 L/ha of Tebuconazol + Trifloxistrobina; 0,4 L/ha of Difenoconazol + Azoxistrobina; 0,12 kg/ha of Azoxistrobina ; 0,16 kg/ha of Azoxistrobina; 2,0 kg/ha of Pyraclostrobina + Metirana;0,4 L/ha of Cyprodinil; and 2,0 kg/ha of Cyprodinil + Fludioxonil with four replications. For each replication, 10 plants were randomized selected and weekly analized in order to check the total number of leaves, number of leaves with pathogens lesion and severity levels of the pathogens on the onions`s leaves . To the yield evaluation, an area of 7,8 m² for each replication was harvested, weighted and the data transformed to kg/ha. On the post-harvest experiment, 100 bulbs per treatment were ramdomnly selected, being 25 bulbs per replication, and then stored in a packing house under local environmental conditions. The bulbs were evaluated each 30days, by measuring their weight, number of bulbs with pathogens and the eliminate bulbs, respectively. All treatments with fungicides were capable to reduce the incidence of Alternaria porri on the onion leaves and produced a lower number of leaves with A. porri symptoms. Generally speaking, all fungicides treatments were able to increase productivity, with exception to the Montana cultivar. The fungicides sprayed for controlling the onion`s leaves against pathogens attacks had also a positive effect on the incidence of the post-harvest pathogens during of onion bulbs. The Bola Precoce cultivar presented the lowest pathogen incidence as well as percentage of eliminated bulbs. The treatments of fungicides sprayed over the onion`s leaves at field condition when tested for postharvest bulbs conservation, were less effective for the Bola Precoce cultivar when compared to Montana and Vitória ones. / Neste trabalho de dissertação, foram executados dois experimentos com fungicidas em folhas de cebola, com os seguintes objetivos: avaliar sua eficiência no controle de doenças foliares, e também verificar, se o período das aplicações dos fungicidas, realizado entre o pós-transplante até a pré-colheita, influenciaria ou não a redução de doenças de pós colheita. Para tanto empregaram-se as cultivares, Vitória, Bola Precoce e Montana. Para a produção de bulbos, o experimento constou da aplicação de 10 tratamentos, incluindo a Testemunha, como segue:0,5 L/ha de Difenoconazola; 1,0 L/ha de Tebuconazola; 0,75 L/ha de Tebuconazola + Trifloxistrobina; 0,4 L/ha de Difenoconazola +Azoxistrobina; 0,12 kg/ha de Azoxistobina; 0,16 kg/ha de Azoxistrobina; 2,0 kg/ha de Pyraclostrobina + Metirana; 0,4 L/ha de Cyprodinila e 2,0 kg/ha de Cyprodinila + Fludioxonila, com quatro repetições. Semanalmente, para cada das 10 plantas marcadas aleatoriamente em cada repetição, fizeram-se as seguintes avaliações: número total de folhas, folhas com lesão de patógenos e severidade dos patógenos nas folhas de cebola. Para a análise de produtividade, foram colhidos e pesados os bulbos numa área de 7,8 m2 por repetição e os dados transformados em kg/ha. No experimento pós-colheita foram separados 100 bulbos de cebola por tratamento, 25 bulbos por repetição e armazenados no galpão do produtor nas condições ambientais da região. Os bulbos foram avaliados a cada 30 dias nos quesitos peso total, peso após o descarte de bulbos com patógenos. Observou-se que todos os tratamentos com fungicidas reduziram a incidência e o número de folhas com sintomas de Alternaria porri. De modo geral, todos os tratamentos com fungicidas proporcionaram incremento em produtividade para as cultivares de cebola, exceto para a cultivar Montana. A aplicação de fungicidas foliares teve efeito positivo sobre a incidência de patógenos nos bulbos em pós-colheita. A cultivar Bola Precoce apresentou menor incidência de patógenos, como também a menor porcentagem de bulbos descartados. Os tratamentos com fungicidas no controle de doenças foliares visando à conservação dos bulbos pós-colheita apresentaram menor eficiência na cultivar Bola Precoce quando comparados com as cultivares Montana e Vitória.

O mofo-branco causado pelo fungo Sclerotinia sclerotiorum se encontra amplamente disperso pelas áreas de produção em todo pais e afeta mais de 400 espécies de planta, causando perdas na produção e redução na qualidade. O controle da doença é considerado difícil, pois o patógeno forma escleródios (estruturas de sobrevivência), que podem permanecer viáveis por vários anos. Normalmente exige-se um manejo integrado, que envolve o controle químico, biológico e diversas práticas culturais, uma vez que cultivares resistentes não estão disponíveis. As adoções de estratégias sustentáveis de manejo do mofo branco dependem da compreensão do patógeno, sua etiologia, morfologia, agressividade e dinâmica populacional. Foram avaliados 150 isolados, coletados em cultivos de cenoura, couve, girassol, nabo, soja e feijão. O índice de velocidade de crescimento micelial (IVCM), a coloração da colônia e densidade do micélio, o tempo necessário para a formação do primeiro escleródio, o número de escleródios por placa, o peso em mg e a forma dos escleródios foram utilizados na caracterização dos isolados. O critério adotado nas avaliações da agressividade dos isolados foi o diâmetro das lesões após diversos intervalos de tempo, usando o método da folha destacada, em feijão e soja. Os valores foram usados para calcular a área abaixo da curva de progresso de doença. A população avaliada mostrou ampla variabilidade para as características morfológicas, fisiológicas e na agressividade. O controle químico é a estratégia mais utilizada no controle do mofo branco. No Brasil, onze ingredientes ativos estão registrados, no entanto, três são mais utilizados: fluazinam, procimidona e tiofanato metílico. O uso intensivo de fungicidas, especialmente os que agem em um unico sitio de ação, podem selecionar isolados resistentes e, consequentemente, levar a falhas de controle. A avaliação da sensibilidade de S. sclerotiorum para os fungicidas mais utilizados é fundamental para monitorar o comportamento da população. Foram avaliadas a sensibilidade de isolados brasileiros de Sclerotinia sclerotiorum a fluazinam, procimidona e tiofanato metílico, atraves de concentrações discriminatórias e valores de CI50 (concentração do fungicida que inibe em 50% o crescimento micelial). Um total de 150 isolados foi testado e nenhum se mostrou resistente a fluazinam ou procimidona. O valor da CI50 para fluazinam variou de 0,00173 ppm a 0,01284 ppm, com média de 0,007 ppm. Para procimidona, a CI50 desses isolados variou de 0,12223 ppm a 0,35916 ppm, com média de 0,21834 ppm. Foram encontrados sete isolados resistentes ao tiofanato metílico, com CI50 variando de 990-2667 ppm. Na população sensível o valor variou de 0,49 - 3,73 ppm. Foi verificada a adaptabilidade dos isolados resistentes, e esta se mostrou comparável a dos isolados sensíveis, sugerindo que os isolados possuem aptidão parasitária suficiente para competir com os isolados sensíveis em condições de campo. / The white mold caused by the fungus Sclerotinia sclerotiorum is widely dispersed in production areas in the whole country and affects more than 400 species, causing production losses and reduced quality. Disease control is considered difficult because the pathogen form sclerotia (survival structure) which can remain viable for several years. Typically this requires a integrated pest management, which involves chemical, biological control and various cultural practices, since resistant cultivars are not available. The adoption of sustainable management strategies for white mold depends on understanding the pathogen, its etiology, morphology, aggressiveness and population dynamics. We evaluated 150 isolates collected from carrots, cabbage, sunflower, turnip, soybeans and beans. Mycelial growth rate index (MIG), colony color and mycelium density, time required to form the first sclerotia, the number of sclerotia per plate, the weight in mg and sclerotia shape were used for the isolates characterization. The criteria used in the isolates aggressiveness evaluations were lesions diameter after various time intervals, using the detached leaf method in bean and soybean. The values were used to calculate the area under the disease progress curve (AUDPC). The population evaluates showed wide variability for morphological, physiological and aggressive characteristics. Chemical control is the most commonly strategy used in the control of white mold. In Brazil, eleven ingredients active are registered, however, three are most commonly used, and they are: fluazinam, procymidone and thiophanate-methyl. The intensive use of fungicides, especially those which act on at a single site of action, can select resistant isolates, and consequently lead to failure control. The evaluation of the sensitivity of S. sclerotiorum to the most commonly used fungicides is critical to monitor the behavior of the population. We assessed the sensitivity of Brazilian Sclerotinia sclerotiorum isolated to fluazinam, procymidone and thiophanate-methyl, through discriminatory concentrations and IC50 values (the fungicide concentration which inhibits 50% of the mycelial growth). A total of 150 strains have been tested, and none were resistant to fluazinam or procymidone. The IC50 value for fluazinam ranged from 0.00173 to 0.01284 ppm ppm, with an average of 0.007 ppm. For procymidone, the IC50 of these isolates ranged from 0.12223 to 0.35916 ppm ppm, averaging 0.21834 ppm. Seven isolates were found resistant to thiophanate-methyl with IC50 ranging from 990-2667 ppm. In sensitive people the value ranged from 0.49 to 3.73 ppm. Adaptability of resistant isolates was observed, and this proved to be comparable to the susceptible isolates, suggesting that the isolates have parasitic fitness enough to compete with susceptible isolates in field conditions.