Under 2013 förbjöds behandling av blommande grödor med de systematiska neonikotinoiderna imidakloprid, klotianidin och tiametoxam i EU. Ett flertal studier och rapporter hade visat att pollinerande biarter kan uppleva subletala effekter av att konsumera neonikotinoid. Oro rådde om bin blir förgiftade av neonikotinoider funna i pollen och nektar hos dessa blommade grödor. Därför har jag undersökt på en kommunal nivå om neonikotinoidbetade rapsareal generellt har medfört en negativ effekt på förekomst av rapspollinerande vildbin. Studien använde observationsdata från medborgarforskning angående 46 vildbiarter som är vanliga i och omkring åkrar, varav 19 är vanliga i rapsfält. Jag sammanställde data över pollinatörer och areal åker med andel raps mellan 2002 och 2020 för 202 kommuner i södra Sverige. Med hjälp av ”Generalized linear mixed model” undersökte jag sambandet mellan oddset att observera rapspollinerande arter bland pollinatörerna och rapsareal. Resultatet visade ingen effekt av ökad mängd raps på rapsbesökare och ingen lägre mängd pollinatörer mellan 2008–2013 då neonikotinoidbetad raps förekom som mest. Frånvaro av negativ effekt på vildbin kan vara på grund av låga koncentrationer av neonikotinoider i nektar och pollen över skalan för denna studie. En eventuell negativ effekt av neonikotinoider från mer raps kan möjligtvis ha vägts upp av den positiv effekt i form av extra resurser som ökar tillväxten hos lokala populationer. Framtida studier uppmanas att vidare undersöka variationen i exponering av neonikotinoider från raps beroende på beteendemässiga skillnader som tillexempel flygtid och socialstruktur. / In 2013, treatment of flowering crops with the systematic neonicotinoids imidacloprid, clothianidin and thiamethoxam were prohibited by the EU. Several studies and reports had shown that pollinating bees can experience sublethal effects by consuming neonicotinoids. Concerns regarded whether bees would be poisoned by neonicotinoids found in pollen and nectar of these flowering crops. Therefore, I have examined on a municipal level, whether area of rapeseed treated with neonicotinoids have generally caused a negative effect on the abundance of wild bees which pollinate on rapeseed. The study used citizen-based observational data of 46 wild bee-species that are common in and around agricultural fields, 19 of which are common in rapeseed-fields. I compiled data regarding pollinators and area of agricultural field with proportions of rapeseed-fields between 2002 and 2020 for 202 municipalities in South Sweden. Using Generalized linear mixed model, I examined the connection between odds of observing rapeseed-pollinating species among pollinators and the area of rapeseed. The result showed no effect from increased amount of rapeseed on rapeseedpollinators and no reduced number of pollinators between 2008-2013, the periodwhenneonicotinoid-treated rapeseed was most abundant. The absence of a negative effect on wild bees could be caused by low concentrations of neonicotinoids in nectar and pollen. Also, possible negative effects of neonicotinoids from rapeseed could possibly be outweighed by a positive effect from additional resources that increases local population growth. Future studies are encouraged to further examine varied exposure of neonicotinoids from rapeseed based of behavioural differences like flight-time and social structure of wild bees.

Neonicotinoid seed treatments are widely used and highly effective against early season insect pests of all row crops throughout the Mid-South region of the United States. An analysis was performed to determine the value of neonicotinoid seed treatments across multiple trials in soybean, Glycine max L.; corn, Zea mays L.; cotton, Gossypium hirsutum L.; and sorghum, Sorghum bicolor L. production systems across the mid-southern region. Neonicotinoid seed treatments provided significant yield and economic increases when utilized the majority of the time. A second experiment was performed to determine the value of various insecticide classes when utilized in an overall systems approach when managing cotton insect pest in the Delta and Hills region of Mississippi. When all classes of insecticides were used in rotation, significant yield and economic benefits were observed in the Delta Region compared to treatment scenarios where some insecticide classes were omitted.

One of the objectives of this research was to evaluate the need for an additional imidacloprid seed treatment on ThryvOn® (Bayer Crop Science®, St. Louis, MO) cotton to effectively manage tobacco thrips, Frankliniella fusca (Hinds). While evaluating thrips densities and damage ratings, ThryvOn cotton continued to display reduced damage and thrips populations than non-ThryvOn. Thrips populations and damage ratings were consistently reduced when incorporating a higher rate of imidacloprid, but they were not reduced enough to justify the higher rates of imidacloprid. Another objective of this research was to evaluate the impact of aldicarb (AgLogic Chemical®, LLC; Chapel Hill, NC) and ThryvOn on reniform nematode, Rotylenchulus reniformis (Linford & Oliveira). The impact of aldicarb and ThryvOn technology had no impact on reniform nematode densities in Mississippi cotton throughout this study. The reduced thrips populations and damage ratings provided by ThryvOn cotton has the potential to improve integrated pest management in the southern U.S.

Seed transmission of <i>Cylindrocladium parasiticum</i> was investigated as a possible explanation for the higher-than-expected incidence of Cylindrocladium black rot (CBR) of peanut in fields fumigated with metam sodium. Sixty-three commercial seed lots from Virginia production fields were examined for the presence of seed with speckled testae, a symptom of seed infection by <i>C. parasiticum</i>. Speckled seed was present in conditioned seed lots in 1998, 1999, and 2000 at an average rate of 1%. Soon after pods were harvested, the fungus was recovered from speckled seed at high frequencies. During winter seed storage, pathogen survival remained high in seed stored at -13 and 4 C, but declined in some seed stored at 15 C and ambient temperatures. Speckled and normal seed with and without fungicide treatment was planted in steam-treated soil in the greenhouse and metam-treated field plots in 1999 and 2000. Speckled seed treated with captan + pentachloronitrobenzene (pcnb) + carboxin transmitted the pathogen to emerging plants in the greenhouse and field. Transmission levels depended on the amount of viable inoculum present in seed at the time of planting. In the field, yield losses were significant when 20% or more of the seed planted was speckled. The low incidence of speckled seed in commercial seed lots would not result in a loss of yield for growers, but may contribute to disease spread. Testing of additional seed treatment fungicides indicated that fludioxonil, tebuconazole, and thiram may offer the best protection against disease spread from seed transmission of <i>C. parasiticum</i>. / Master of Science

A associação da adubação nitrogenada com bactérias diazotroficas como o Azospirillum brasiliense pode favorecer o estabelecimento da planta em campo, além de constituir complemento nutricional para a planta de milho doce (Zea mays L. grupo saccharata). Os objetivos do trabalho foram: avaliar a interferência da inoculação de diferentes doses do produto comercial Azomax (Azospirillum brasiliense estirpes Ab-V5 e Ab-V6) na qualidade das sementes de milho doce, especialmente a germinação e o vigor e a interferência da inoculação no estabelecimento da planta em campo, avaliando desde a emergência da plântula até a maturação da planta, associada a adubação nitrogenada. As sementes foram inoculadas nas doses de 0 (controle), 2, 4 e 8 mL de Azospirillum/kg de sementes e em campo, combinadas a níveis de adubação nitrogenada de 80, 120, 160 e 200 kg de nitrogenio por hectare (blocos casualizados, esquema fatorial). A inoculação das sementes de milho doce com a bactéria Azospirillum brasiliense favoreceu o desenvolvimento radicular alterando o comprimento de raízes, diâmetro médio e massa de matéria seca; favoreceu o desenvolvimento da parte aérea proporcionando variações no teor de clorofila, diâmetro de colmo e teor de nitrogênio e apesar de não resultar em aumentos significativos da produtividade, influenciou no aumento do número de fileiras de grãos. A inoculação com Azospirillum por quilograma de não prejudicou a qualidade das sementes por até 60 dias após a inoculação. / The association of nitrogen fertilization with the inoculation of diazotrophic bacteria, such as Azospirillum brasiliense, might favor the plant establishment in the field and can work as a nutritional complement for sweet corn plants (Zea mays L. saccharate group). Taking from this combined action, the objective of this research was to evaluate the development and productivity of the sweet corn plant as a function of the inoculation and nitrogen fertilization in a randomized block design in a factorial scheme (4 x 4), 80, 120, 160 and 200 kg of nitrogen / ha) and 0, 2, 4 and 8 mL of Azospirilum / kg of seeds, with four replicates for each treatment. The inoculation of sweet corn seeds with Azospirillum brasiliense favored root development by increasing its length, diameter and amount of dry matter; favored the development of the plant by increasing content of chlorophyll, stem diameter and nitrogen content and despite not affecting significantly the yield of the plant increased number of grain rows. The application of Azospirillum have not caused negative effects on seed storage up to 60 days after inoculation.

Made available in DSpace on 2017-07-25T19:29:48Z (GMT). No. of bitstreams: 1 CarlosASchipanski.pdf: 743340 bytes, checksum: 82ebbcfc2be8edf6e9fe39a210220464 (MD5) Previous issue date: 2011-04-29 / The aim of this study was to evaluate the effects of fungicides and resistance inducer acibenzolar-S-methyl applied as seed treatment associated with foliar applications sprays of fungicides in corn on the control of common rust of corn, caused by the fungus Puccinia sorghi. To achieve this objective to experiments were carried out. On the first experiment, the P. sorghi was inoculated in the laboratory and the effects of the following fungicides were evaluated: fluquinconazol (10 g ia/60.000 seed 1), flutriafol (3 g ai), azoxystrobin (15 g ia), carbendazin ( 10 g ia), carbendazin + thiram (9 + 21 g ia), carboxin + thiram (12 + 12 g ia), fludioxonil + metalaxyl - m (3 + 7.5 g ia) fludioxonil + mefenoxam + thiabendazole (1 + 6 +0.8 g ia), difenoconazole (6 g ia), acibenzolar-s-methyl (12.5 g ia) and thiophanate methyl +fluazinam (14 + 2.1 g ia). After inoculation, the plants were assessed to count the number of lesions at 7, 14 and 21 days after inoculation (DAI), fresh and dry weight, root length and shoot at 21 DAI. After the assessments it was observed that the fungicides azoxystrobin and fluquinconazol had the highest levels of control of the disease, and the levels of control from the other products tested varied from 23.7 to 49.9% control. No effects of these products were observed on the green and dry weight, length of roots and shoots of maize plants. In the second experiment conducted under field conditions, the effects of the following fungicides were evaluated: fluquinconazol (10 g ia/60.000 seed-1), azoxystrobin (15 g ia) carbendazin (10 g ia) in seed treatment in combination with foliar fungicides sprays. At the V4 stage, the fungicides azoxystrobin (60 g ai ha-1) and azoxystrobin + cyproconazole (60 +24 g ai ha-1) were used and at the V9 stage azoxystrobin + cyproconazole (70 + 28 g ai ha-1). The treatments were combined in a 4x3x2 factorial structure, with 24 treatments and four replications. The rust severity assessments levels started after sowing and the plumule leaf emergence, considering as 1 (full emergence of the plumule leaf above ground), 7, 14, 21, 28, 35 , 42, 49, 56 days after emergence (DAE), severity of common rust at the stages VT, R3 and R5, plant height at 21 and 28 DAE, incidence of stalk rot and mold grains, the 1000 grain weight, final stand and productivity. A significant effect of the fungicides azoxystrobin, fluquinconazol and carbendazin as seed treatment on reducing the severity of common rust of corn until 56 DAE. The treatment with azoxystrobin presented a better result. However, the effect of the seed treatment was suppressed at the 28 DAE when associated with the foliar sprays. The foliar sprays in V4 stage reduced the severity of the common rust and no differences between the fungicides azoxystrobin and azoxystrobin + cyproconazole were oberved. The spray with azoxystrobin + cyproconazole in V9 stage also contributed to the decrease of the disease severity. A greater reduction of disease severity was observed when the sprays were done at the V4 and V9 stages. No treatment effect was observed on the incidence of stalk rot, grain molds, final stand, southern rust and gray leaf spot severity. Only the carbendazin fungicide seed treatment presented a significant effect in relation to the yield. / O objetivo deste trabalho foi avaliar os efeitos dos fungicidas e do indutor de resistência acibenzolar-S-methyl aplicados via tratamento de sementes e posteriormente da associação dos fungicidas nas sementes às aplicações de fungicidas foliares na cultura do milho sobre o controle da ferrugem comum, causada pelo fungo Puccinia sorghi. Para cumprir tal objetivo foram montados dois experimentos. No primeiro, a P. sorghi foi inoculada em condições de laboratório e foram testados o efeito do tratamento de sementes com os fungicidas fluquinconazole (10 g i.a./60.000 sementes-1), flutriafol (3 g i.a.), azoxystrobin (15 g i.a.), carbendazin (10 g i.a.), carbendazin + thiram (9 + 21 g i.a.), carboxin + thiram (12 + 12 g i.a.), fludioxonil + metalaxyl – m (7,5 + 3 g i.a.), fludioxonil + mefenoxam + thiabendazole (1 +0,8 + 6 g i.a.), difenoconazole (6 g i.a.), thiophanate methyl + fluazinam (14 + 2,1 g i.a.) e do indutor de resistência acibenzolar-S-methyl (12,5 g i.a.). Após a inoculação das plantas foram realizadas as avaliações de contagem de número de lesões aos 7, 14 e 21 dias após a inoculação (DAI), peso verde, peso seco e comprimento de raízes e parte aérea aos 21 DAI. Foi observado que os fungicidas azoxystrobin e fluquinconazole apresentaram os maiores níveis de controle da doença, e os demais produtos testados apresentaram valores entre 23,7 49,9% de controle. Não foi observado efeito dos produtos sobre o peso verde, peso seco e comprimento tanto de raízes quanto de parte aérea das plantas de milho. No segundo experimento, realizado em condições de campo, foram avaliados a eficácia dos fungicidas fluquinconazole (10 g i.a./60.000 sementes-1), azoxystrobin (15 g i.a.) e carbendazin (10 g i.a.) via tratamento de sementes em associação com aplicações foliares de fungicidas, sendo no estádio V4 os fungicidas azoxystrobin (60 g i.a. ha-1) e azoxystrobin + ciproconazole (60 +24 g i.a. ha-1) e no estádio V9 os fungicidas azoxystrobin + ciproconazole (70 +28 g i.a. ha-1). Os tratamentos foram combinados em um esquema fatorial 4x3x2, totalizando 24 tratamentos com 4 repetições. Após a semeadura, aguardou-se a emergência da folha plumular e iniciaram-se as avaliações de severidade (%) de ferrugem comum do milho aos 1 (emergência total da folha plumular acima do solo), 7, 14, 21, 28, 35, 42, 49, 56 dias após a emergência (DAE), severidade de ferrugem comum nos estádios VT, R3 e R5, altura de plantas aos 21 e 28 DAE, incidência de colmos doentes e grãos ardidos, peso de 1000 grãos, estande final e produtividade. Foi observado efeito dos fungicidas azoxystrobin, fluquinconazole e carbendazin via tratamento de semente sobre a redução da severidade de ferrugem comum do milho até os 56 DAE e o azoxystrobin foi superior aos demais. No entanto, quando associado às aplicações foliares o efeito dos fungicidas via tratamento de sementes foi suprimido aos 28 DAE. As aplicações foliares em V4 reduziram a severidade de ferrugem comum e não se observou diferença entre os fungicidas azoxystrobin e azoxystrobin ciproconazole. A aplicação de azoxystrobin ciproconazole em V9 também contribuiu para a redução da severidade da doença e quando ambas as aplicações foram combinadas notou-se uma redução ainda maior. Não foi observado efeito dos tratamentos sobre a incidência de colmos doentes e grãos ardidos, estande final, severidade de ferrugem polissora e cercosporiose. Em relação à produtividade, somente o fungicida carbendazin via tratamento de sementes apresentou resposta significativa.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-03-30T15:37:38Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_leonir_flach.pdf: 318187 bytes, checksum: 18084d61e9bb08da2b5e1c3dcda58b51 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-05T19:09:32Z (GMT) No. of bitstreams: 2 dissertacao_leonir_flach.pdf: 318187 bytes, checksum: 18084d61e9bb08da2b5e1c3dcda58b51 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-05T19:10:29Z (GMT) No. of bitstreams: 2 dissertacao_leonir_flach.pdf: 318187 bytes, checksum: 18084d61e9bb08da2b5e1c3dcda58b51 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-05T19:10:42Z (GMT). No. of bitstreams: 2 dissertacao_leonir_flach.pdf: 318187 bytes, checksum: 18084d61e9bb08da2b5e1c3dcda58b51 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-06-01 / Sem bolsa / Considerando a importância do tratamento e da manutenção da qualidade da semente durante o armazenamento, objetivou-se através deste trabalho avaliar o desempenho fisiológico de sementes de algodão tratadas quimicamente e armazenadas em condição ambiente. O delineamento experimental foi inteiramente casualizado, com 6 repetições, em esquema fatorial 9 x 6 (tratamentos x época de avaliação). Foram realizados os seguintes tratamentos de sementes: T1 – Testemunha (sem tratamento); T2 – Fungicida Carbendazin 150g/l e Tiran 350g/l (600 ml/100 kg de sementes); T3 – Fungicida Triadmenol 150g/l (200 ml/100 kg de sementes); T4 – Fungicida Pencicurom 250g/l (300 ml/100 kg de sementes); T5 – Fungicida Azoxistrobina 75g/l, Metalaxil-M 37,5g/l e Fludioxonil 12,5 g/l (300 ml/100kg de sementes); T6 – Inseticida Imidacloprido 150 g/l e Tiodicarbe 450g/l (2400 ml/100kg de sementes); T7 – Inseticida Tiametoxam 350g/L (600ml/100kg de sementes); T8 – Composto pelos tratamentos 2, 3, 4 e 6 mencionados acima; T9 – Composto pelos tratamentos 5 e 7. A avaliação da qualidade fisiológica das sementes de algodão foi realizada aos 0, 30, 60, 90, 120 e 150 dias de armazenamento através dos testes de germinação e vigor (baixa temperatura e envelhecimento acelerado). Os resultados permitem constatar que os produtos (triadmenol) e o (carbendazin e tiran + triadmenol + Pencicurom + imidacloprido e tiodicarbe) reduzem os percentuais de germinação e vigor da sementes de algodão. A qualidade fisiológica é negativamente afetada conforme se aumenta o período de armazenamento. / Considering the importance of treatment and maintenance of seed quality during storage, the aim through this work was to evaluate the physiological performance of cotton seeds chemically treated and stored at room temperature. The experimental design was completely randomized with six replications in factorial scheme 9 x 6 (treatments x evaluation time). The following seed treatments were used: T1 - control (no treatment); T2 - Fungicide Carbendazin 150g / l Tiran 350g / l (600 ml / 100 kg seed); T3 - Fungicide Triadmenol 150g / l (200 ml / 100 kg seed); T4 - Fungicide Pencicurom 250g / l (300 ml / 100 kg seed); T5 - Fungicide Azoxystrobin 75g / l, Metalaxyl-M 37,5g / l Fludioxonil 12.5 g / l (300 ml / 100kg seed); T6 - insecticide Imidacloprid 150 g / l Thiodicarb 450g / l (2400 ml / 100kg seed); T7 - insecticide thiamethoxam 350 g / L (600ml / 100kg of seeds); T8 - for treatments compound 2, 3, 4 and 6 mentioned above; T9 - Composed by treatments 5 and 7. The evaluation of the physiological quality of cotton seeds was performed at 0, 30, 60, 90, 120 and 150 days of storage through the germination and vigor tests (low temperature and accelerated aging). The results help determine that the product (triadmenol) and (carbendazin and tyranny + triadmenol + Pencicurom + imidacloprid and thiodicarb) reduce the percentage of germination and vigor of cotton seeds. The physiological quality is adversely affected as increases the storage period.

A produção de alimentos orgânicos amplia a demanda por sementes e a atual legislação brasileira requer a utilização de sementes orgânicas. O tratamento das sementes com produtos biológicos, à base de Bacillus e Trichoderma, possibilita o controle de patógenos e interfere na germinação da semente e no desenvolvimento da plântula. Deste modo, foi avaliado o parâmetro fisiológico das sementes de cenoura (Daucus carota L.) após aplicação de produtos biológicos à base de Bacillus spp. e Trichoderma spp., com avaliações imediatas e aos 60, 120 e 180 dias de armazenamento. Para isto, foram utilizadas sementes de cenoura, quatro cultivares de verão, \'Brasília\', \'Bruna\', \'Erica\' e \'Francine\', considerando os seguintes tratamentos: Controle, Bacillus spp. cepas 1 e 2, Trichoderma spp. e Trichoderma harzianum e avaliadas por meio dos testes de germinação, emergência da plântula, primeira contagem de germinação, índice de velocidade de germinação, índice de velocidade de emergência da plântula, comprimento da raiz e da plântula e sanidade. O Trichoderma harzianum causa fitotoxidez nas plântulas de cenoura dos cultivares Brasília, Bruna e Erica, quando avaliadas, no teste de germinação e quanto ao comprimento, imediatamente após a aplicação dos produtos nas sementes. Em termos fisiológicos, a qualidade das sementes dos cultivares Brasília, Bruna e Erica, não foi afetada quando tratadas previamente ao armazenamento. A eficácia do controle dos principais patógenos das sementes de cenoura variou em função do armazenamento das sementes tratadas, bem como do cultivar. Os produtos biológicos reduziram a incidência dos principais patógenos das sementes de cenoura. / Organic foods production increases the demand for seeds and current Brazilian legislation requires the use of organic seeds. The treatment of seeds with biological products, based on Bacillus and Trichoderma, allows the control of pathogens and interferes in seed germination and seedling development. The physiological parameters of carrot seeds (Daucus carota L.) were evaluated immediately after the treatment with biological products based on Bacillus spp. and Trichoderma spp., and upon 60, 120 and 180 days of storage. Four summer cultivars of carrot seeds \'Brasília\', \'Bruna\', \'Erica\' and \'Francine\', were analyzed considering the following treatments: Control, Bacillus spp. Strains 1 and 2, Trichoderma spp. and Trichoderma harzianum, and they were evaluated by germination tests, seedling emergence, first germination count, germination speed index, seedling emergence speed index, root and seedling length, and sanity. Trichoderma harzianum causes phytotoxicity in the carrot seedlings of the cultivars Brasília, Bruna and Erica, when evaluated the germination test and in the length, immediately after the application of the products in the seeds. In physiological terms, the seed quality of the cultivars Brasília, Bruna and Erica, were not affected when treated prior to storage. The effectiveness of the control to the main pathogens of the carrot seeds varied as a function of the treated seeds storage, as well as of the cultivar. Biological products have reduced the incidence of major pathogens in carrot seeds.

O melão é uma fruta de grande importância para o comércio de exportação do Brasil e, embora restrito a um pequeno número de estados produtores, o cultivo dessa fruta ampliou-se de forma significativa nos últimos anos. Um dos maiores problemas para essa cultura é a presença de patógenos, como a bactéria Acidovorax avenae subsp. citrulli (Aac), responsável por perdas de até 100%. O uso de sementes garantidamente sadias é a principal e mais efetiva medida de controle preconizada para essa bacteriose. Este trabalho teve como objetivo selecionar, in vitro e posteriormente in vivo, produtos capazes de erradicar a bactéria Aac de sementes de melão. Sessenta produtos fitossanitários comerciais foram selecionados para a avaliação do controle in vitro de quatro isolados, sendo nove bactericidas e 51 fungicidas, correspondendo a 6 e 45 ingredientes ativos distintos, respectivamente. Além desses produtos, avaliou-se também o efeito do óleo de melaleuca e do ácido peroxiacético sobre o crescimento dos isolados. Nos ensaios in vivo, sementes inoculadas e naturalmente infectadas foram tratadas, de maneira convencional e a vácuo, com os produtos e doses selecionados no ensaio in vitro. Todas as plântulas foram avaliadas quanto à presença de sintomas característicos de mancha-aquosa aos 21 dias após a emergência. Os antibióticos casugamicina (100 e 200 ug/L), oxitetraciclina (10, 100 e 200 ug/L), oxitetraciclina+sulfato de cobre (10, 100 e 200 ug/L), os fungicidas captana, carboxina+tiram, cloreto de benzalcônio, mancozebe+oxicloreto de cobre, metiram, metiram+piraclostrobina e tebuconazol, nas doses de 100 e 200 ug/L e o ácido peroxiacético a partir da dose de 300 ug/L apresentaram resultados satisfatórios na avaliação in vitro. No ensaio in vivo nenhum tratamento foi eficiente na erradicação da bactéria das sementes. / Melon is a fruit of great importance for the export trade of Brazil. Although cultivated in a small number of states, the cropping of this fruit has expanded significantly in recent years. Pathogens represent the most limiting factors, among which stands out the bacterium Acidovorax avenae subsp. citrulli (Aac), responsible for up to 100% losses. The use of healthy seed is the main and the most effective control measure of this bacterium. This study aimed to select first in vitro and subsequently in vivo, erradicant chemicals of Aac in melon seeds. Sixty commercial products were were tested in vitro in the control of four isolates, being nine bactericides and 51 fungicides, corresponding to six and 45 distinct active ingredients, respectively. Besides these products the effects of oil of the melaleuca tea tree and peroxyacetic acid were also evaluated. In the in vivo tests, inoculated and naturally infected seeds were treated by conventional manner and under vacuum, with the products and doses selected in the in vitro test. All seedlings were evaluated for the presence of characteristic bacterial fruit blotch symptoms at 21 days after emergence. The antibiotics kasugamycin (100 and 200 ug/L), oxytetracycline (10, 100 and 200 ug/L), oxytetracycline+copper sulphate (10, 100 and 200 ug/L), the fungicides captan, carboxin+thiram, benzalkonium chloride, mancozeb+copper oxychloride, metiran, metiran+pyraclostrobin and tebuconazole at doses of 100 and 200 ug/L and peroxyacetic acid at the dose of 300 ug/L showed satisfactory results in the in vitro control of the bacterium. However, no chemical efficiently eradicated the bacterium from the seeds in the \"in vivo\" tests.

Made available in DSpace on 2016-12-08T16:44:35Z (GMT). No. of bitstreams: 1 PGPV10MA051.pdf: 9509965 bytes, checksum: 86ccbfb02055f2163caee57861d61b0a (MD5) Previous issue date: 2010-02-22 / The southern states of Brazil are responsible for most of the national wheat production. However, is one of most important factor to produced wheat in southern Brazil, is the excess accumulation of rain and cloudy days, favoring the occurrence and increase diseases intensity. Necrotrophic fungi survive on seed and wheat straw, and among them, the fungus Alternaria alternata is considered one of the causal agents of wheat black point seeds. This disease is commonly found in wheat seeds in Brazil, but no reports of survival, seeds viability, transmission and control measures by seeds the treatment. The aim of this study was to evaluate the presence of A. alternata in wheat seed produced in southern Brazil, to quantify the viability of the fungus in stored seeds, during the inter-harvest period, and to evaluate the fungicides efficacy to Alternaria seed treatment indicated by the Wheat Research Committee to seed treatment to Alternaria control. In 2007 growing seasons, the presence of the fungus A. alternata was quantified in 75 wheat seeds samples at south Brazil, at three regions of Cropping and Use Value (CUV I, II and III). Before seeding them in potato-dextrose-agar media + antibiotic (PDA+A), two hundred seeds per sample were disinfested. The survival of A. alternata was established by the seeds from the 2008 harvest, stored inside propylene bags at a storehouse during 180 days- inter-harvest period being evaluated each 45 days. Three seed lots were analyzed from six wheat cultivars. The efficacy of fungicides to control the A. alternata was determinate by the treatment of the seeds sowed in PDA+A environment, with 400 seeds by treatment. The A. alternata was detected at all of the evaluated samples, with the average incidence of 39.6%, with the incidences of 48.0%, 38.8% and 35.9% respectively for CUV I, CUV II and CUV III regions. At CUV I region, the coolest and moistest region, had the biggest average incidence of the fungus, being significantly different than the others. The viability of A. alternata had average reduction of 49.5% in the mean of wheat cultivars during the inter-harvest, proving that infected seeds are primary inoculum source for the fungus. The fungicide iprodione+triticonazol was the most efficient to control the A. alternata in vitro / Os Estados da região sul do Brasil são responsáveis pela maior parte da produção tritícola nacional. Uma das dificuldades encontradas na produção trigo no sul do Brasil é o excesso de chuva e o acúmulo de dias encobertos, favoráveis à ocorrência e o aumento da intensidade de doenças. Fungos necrotróficos sobrevivem em sementes e na palha do trigo. Dentre eles, o fungo Alternaria alternata, é considerado um dos agentes causais de ponta preta em sementes de trigo. Comumente é detectado em sementes de trigo no Brasil. Porém, sem relatos de sua sobrevivência, viabilidade nas sementes, transmissão para planta e medidas de controle que envolva o tratamento de sementes. O objetivo deste trabalho foi detectar a presença de A. alternata em sementes de trigo produzidas no Sul do Brasil, quantificar a viabilidade do fungo em sementes armazenadas no período de entre safra e testar a eficácia dos fungicidas indicados pela Comissão de Pesquisa de Trigo para tratamento de sementes visando ao controle de A. alternata. A detecção do fungo foi quantificada em 75 amostras de sementes de trigo no Sul do Brasil, na safra agrícola de 2007, em três Regiões de Valor de Cultivo e Uso (VCU I, II e III). Duzentas sementes por amostra foram desinfestadas antes de serem plaqueadas em meio de batata-dextrose-ágar + antibiótico (BDA+A). Sobrevivência de Alternaria alternata foi determinada em sementes colhidas na safras 2008 e armazenadas em sacos de propileno em armazém de alvenaria durante 180 dias, período de entre safra, com avaliações em intervalos de 45 dias. Foram analisados três lotes de sementes de seis cultivares de trigo. A eficácia de fungicidas no controle de A. alternata foi determinada via tratamento de sementes, plaqueadas em meio de BDA+A, com 400 sementes por tratamento. Foi detectado A. alternata em todas as amostras analisadas, com incidência média de 39,6%, sendo 48,0%, 34,8% e 35,9%, respectivamente para Regiões de VCU1, VCU2 e VCU3. Na Região VCU1, considerada mais fria e úmida, houve maior incidência média do fungo, diferindo significativamente das demais. Houve redução média de 49,5% na viabilidade de A. alternata na média das cultivares de trigo durante o período de entre safra, comprovando que as sementes infectadas são fonte de inóculo primário para o fungo. O fungicida iprodiona+triticonazole foi o mais eficiente no controle de A. alternata in vitro