• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 72
  • 40
  • 7
  • 7
  • 4
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 198
  • 53
  • 40
  • 39
  • 33
  • 26
  • 24
  • 18
  • 18
  • 17
  • 16
  • 16
  • 15
  • 14
  • 13
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Wheat Yield, Quality, and Profitability as Affected by Nitrogen Application Rate, Foliar Fungicide Application, and Wheat Variety in Soft Red Winter Wheat

Brinkman, Jonathan 16 August 2012 (has links)
The simple effects of nitrogen rates, fungicide application, and varietal responses on wheat yield and quality have been studied individually, but interactions among the inputs are less well understood. Traditionally, increased nitrogen rates have led to higher risk of lodging and disease severity (Roth and Marshall, 1987), but it has been found that fungicides can be used to delay the onset of disease (Gooding et al. 1999). Similarly, yield responses to application of a fungicide may be affected by available nitrogen (Olesen et al., 2003). Wheat quality parameters such as protein, test weight, and alveograph parameters may also be affected by different management systems. Recent Ontario research shows interactions between fungicide and wheat varieties, even in the absence of disease, but the relationships are poorly understood. Current field crop recommendations would be improved by knowledge of interactions between inputs in more intensive management systems. Field experiments were established on nine farm fields in southwestern Ontario to investigate possible interactions among nitrogen rates, fungicides, and varieties. Eight fungicide timing combinations were applied as splits on three N rate blocks (100, 135, and 170 kg ha-1), applied across variety strips (between three and seven) in a split-strip-plot design with three replicates. Measurements included leaf disease severity, fusarium head blight incidence and severity and mycotoxin concentrations, grain yield and yield components, protein, test weight, and alveograph parameters. An economic analysis was performed on the combinations of treatment variables toward the development of more comprehensive recommendations. Interaction between N application rate and fungicide application resulted in greater yield gains with increased N when fungicides were used. Grain protein concentration increased at higher N application rates. Revenue net of the variable costs examined was not significantly affected by N rate alone, while effect of fungicide application varied with site. / Agricultural Adaptation Council, Grain Farmers of Ontario
82

T-PHYLLOPLANIN AND <i>CIS</i>-ABIENOL, TWO NATURAL PRODUCTS FROM TOBACCO HAVE BROAD SPECTRUM, ANTI-FUNGAL ACTIVITIES

King, Brian Christopher 01 January 2011 (has links)
Tobacco phylloplanins (T-phylloplanin) are a group of closely-related glycoproteins that are formed and disposed at the interface between the plant aerial surface (the phylloplane) and the atmosphere. They are synthesized in short procumbent trichomes and are secreted to aerial surfaces where they are thought to serve the plant as a first line of defense against fungal pathogens. Here it is shown using in vitro and in planta assays that tobacco and sunflower phylloplanins have broad-spectrum antifungal activities against spores - and also hyphae for two species - of several true fungi. Field tests show that T-phylloplanin reduces diseases caused by three important fungal pathogens of turf grasses. Tobacco phylloplanins are distinct proteins but they have properties in common with small, membrane-pore-forming, antimicrobial peptides formed by other organisms. To directly determine if T-phylloplanin has pore-forming activity we monitored conductivity change and specific ion leakage from spores and hyphae in suspension. Results indicate that phylloplanin causes fungal membrane disruption that leads to ion depletion and cell death. Having observed broad efficacy of T-phylloplanin against spores and/or hyphae of several true fungi, but no activity towards hyphae of the oomycetes, Pythium and Peronospora parasitica, we tested for possible effects on zoospores of the latter two pathogens. T-phylloplanin was shown to be effective against their zoospores, extending the efficacy of T-phylloplanin to include water molds. In the course of these experiments we also tested the effects of the diterpene cis-abienol that is secreted from tall trichomes of tobaccos and found this compound impacted zoospores and could prevent black shank disease caused by P. parasitica when applied to soil-grown tobaccos as a root drench. Thus, results of these studies with phylloplanins and cis-abienol, two different tobacco surface accumulated compounds are consistent with their serving the plant as first line of defense systems against a wide array of invading fungal pathogens. Phylloplanins and cis-abienol may be useful for controlling fungal diseases in tobacco float beds. The efficacy shown here for T-phylloplanin control of fungal pathogens of turf grasses in the field suggests that this natural product may find use in IPM of turf and other crops.
83

IMPACT OF HIGH-INPUT PRODUCTION PRACTICES ON SOYBEAN YIELD

Jordan, Daniel L. 01 January 2010 (has links)
High-input management practices are often heavily marketed to producers to increase soybean [Glycine max (L) Merr.] yield in already high-yielding environments. Field research was conducted in three locations within 6 states (Arkansas, Iowa, Kentucky, Louisiana, Michigan, and Minnesota) in 2009 to determine the effect of seed treatment, inoculant, foliar fungicide, additional soil fertility beyond state recommendations, foliar fertilizer, increased population over state recommendations, and narrow row spacing on yield. The high-input system (combination of the management practices) yielded higher than standard-input system (University recommended management practices) in only 8 of the 18 locations. Narrow rows, in both the high and standard-input systems, only increased yield in 4 locations. Inoculant did not increase yield at any location. Foliar fertilizer application and seed treatment increased yield in one location each. The additional soil fertility and fungicide application increased yield in two locations each. The increased population increased yields in 3 of the 18 locations; while an additional fungicide application at R5 only increased yield in 1 location. Foliar fertilizers at rates above commercial use did not increase soybean yield in Kentucky in 2008 or 2009. High-input production practices were largely unsuccessful at increasing soybean yield in these studies.
84

Azoles and Contaminants in Treated Effluents Interact with CYP1 and CYP19 in Fish :

Beijer, Kristina January 2015 (has links)
Numerous contaminants are present in mixtures in the aquatic environment. Among these are the azoles, a group of chemicals that includes both pharmaceuticals and pesticides. Azole fungicides are designed to inhibit lanosterol 14-demethylase (cytochrome P450 (CYP) 51), while other azoles are intended to inhibit aromatase (CYP19), i.e. the enzyme catalyzing biosynthesis of estrogens. In fish, a variety of CYP enzymes are involved in biotransformation of waterborne contaminants, and in metabolism of endogenous compounds including steroidal hormones. The induction of CYP1A protein and 7-ethoxyresorufin O-deethylase (EROD) activity are common biomarkers for exposure to aryl hydrocarbon receptor (AhR) agonists in fish. We developed an assay to measure inhibition of CYP1A activity (EROD) in three-spined stickleback and rainbow trout gill tissue ex vivo. Several azole fungicides were found to be potent inhibitors of CYP1A activity. A wastewater effluent containing high concentrations of pharmaceuticals was also shown to inhibit CYP1A activity. Further, several azoles inhibited CYP19 activity in rainbow trout brain microsomes in vitro. Azole mixtures reduced both CYP1A and CYP19 activity monotonically and in an additive way. Given the additive action of the azoles, studies to determine adverse effects of azole mixtures on CYP-regulated physiological functions in fish are needed. Induction of EROD and of gene expression of CYP1 in several organs was observed in an in vivo exposure with the same effluent shown to inhibit EROD. This finding could imply that there was a mixture of AhR agonists and CYP1A inhibitors in the effluent. Finally, wastewater treatment technologies were evaluated using biomarker responses in rainbow trout exposed to effluents of different treatments. The results from chemical analysis together with the biomarker results show that ozone and granulated active carbon treatment removed most pharmaceuticals, as well as AhR agonists and other chemicals present in the regular effluent. This part of the thesis demonstrates that biomarkers in fish such as induction of CYP1 gene expression are applicable to evaluate the efficiency of different treatment technologies for wastewater.
85

CHARACTERIZATION OF <em>COLLETOTRICHUM</em> SPECIES CAUSING BITTER ROT OF APPLES IN KENTUCKY ORCHARDS

Munir, Misbakhul 01 January 2015 (has links)
Multiple species of Colletotrichum can cause bitter rot disease of apple, but the identities and relative representation of the species causing the disease in Kentucky are unknown. A total of 475 Colletotrichum isolates were collected from diseased apples in 25 counties and characterized both morphologically and by using various molecular approaches. Four morphotypes corresponded to reported descriptions of bitter rot species. Morphotype 1, distinguished by the production of a pink color on potato dextrose agar (PDA), orange conidial masses, and fusiform spores, was consistent with C. acutatum. Morphotype 2, which produced gray or white mycelial colonies with orange conidial masses and fusiform spores, was also similar to C. acutatum. Morphotype 3 had abundant gray mycelium and rounded spores and was identical to C. gloeosporioides. Morphotype 4 produced ascospores and resembled Glomerella cingulata. Species-specific polymerase chain reaction (PCR) indicated that both Morphotype 1 and Morphotype 2 belonged to the C. acutatum species complex, whereas Morphotype 3 and Morphotype 4 corresponded to the C. gloeosporioides complex. Multigene sequence analyses revealed that sample isolates belonged to several newly erected species within these species complexes. Morphotype 1 was identified as C. fioriniae, which resides within the C. acutatum species complex. Morphotype 2 was identified as C. nymphaeae, which is also a species within the C. acutatum species complex. Some isolates of Morphotype 3 were identified as C. siamense and some as C. theobromicola; both species are grouped within the C. gloeosporioides species complex. Morphotype 4 was identified as C. fructicola, which is also placed within the C. gloeosporioides species complex. C. fioriniae was the most common species causing bitter rot in Kentucky, comprising more than 70% of the isolates. Molecular fingerprinting using random amplified polymorphic DNA (RAPD) suggested that isolates within C. fioriniae belonged to a relatively homogeneous population, while isolates within C. siamense, C. theobromicola and C. fructicola were more diverse. Infectivity tests on detached fruit showed that C. gloeosporioides species-complex isolates were more aggressive than isolates in the C. acutatum species complex. However, isolates within the C. acutatum species complex produced more spores on lesions compared to isolates within the C. gloeosporioides species complex. Aggressiveness varied among individual species within a species complex. C. siamense was the most aggressive species identified in this study. Within the C. acutatum species complex, C. fioriniae was more aggressive than C. nymphaeae, causing larger, deeper lesions. Apple cultivar did not have significant effect on lesion development. However, Colletotrichum species produced more spores on Red Stayman Winesap than on Golden Delicious. Fungicide sensitivity tests revealed that the C. acutatum species complex was more tolerant to thiophanate-methyl, myclobutanil, trifloxystrobin, and captan compared to the C. gloeosporioides species complex. The study also revealed that mycelial growth of C. siamense was more sensitive to tested fungicides compared to C. fructicola and C. theobromicola. These research findings emphasize the importance of accurate identification of Colletotrichum species within each species complex, since they exhibit differences in pathogenicity and fungicide sensitivity.
86

Integrated management of Cercospora leaf spot on sugar beet

Larson, Ben James. January 2004 (has links) (PDF)
Thesis (M.S.)--Montana State University--Bozeman, 2004. / Typescript. Chairperson, Graduate Committee: Barry J. Jacobsen. Includes bibliographical references.
87

Hémisynthèse de dérivés de l’acide grandiflorénique et évaluation préliminaire de leur activité biologique. / Hemisynthesis of grandiflorenic acid derivatives and evaluation preliminary of their biological activity.

Rios tesch, Nurby nahiely 21 December 2017 (has links)
Ces travaux de thèse décrivent l’hémisynthèse de dérivés de l’acide grandiflorénique (AG). Ce produit naturel a dans un premier temps été converti en ent-kaur-9(11),16-dien-19-ol, composé qui a ensuite été estérifié dans les conditions de Steglich par une série d’acides benzoïques diversement substitués. Aux douze nouveaux composés ainsi obtenus a été ajoutée la synthèse du 9(11),16-dien-19-(2- méthyl-5-nitro-1H-imidazol-1-yl)éthyl-ent-kaurène. Ces dérivés de l’AG ont été soigneusement purifiés, puis complètement caractérisés (IR, SM, RMN 1D et 2D) en vue de leur évaluation biologique. L’activité antibactérienne a été testée sur différentes souches bactériennes comme Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa et Escherichia coli. Les propriétés fongicides ont été évaluées sur Candida albicans et C. krusei. L’activité anti-inflammatoire in vivo a été étudiée sur des souris BIO:NMRI en utilisant le test de l’oedème de l’oreille induit par le xylol. Les dérivés d’acide grandiflorénique n’ont malheureusement montré aucune activité antibactérienne, ni antifongique, mais leur activité anti-inflammatoire s’est montrée prometteuse dans le cas de l’inflammation aiguë, le 9(11),16-dien-18-[2-(4-isobutylphényl)propyl]-ent-kaurène se révélant être le meilleur composé. / This thesis work describes the hemisynthesis of grandiflorenic acid (GA) derivatives. GA natural product was first converted into ent-kaur-9(11),16 dien-19-ol, which was next esterified under Steglich conditions with a series of diversely substituted benzoic acids. To the twelve new compounds thus obtained, was added the preparation of the 9(11),16-dien-19-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl-entkaurene. All these new GA derivatives were carefully purified, and then fully characterized (IR, MS, 1D and 2D NMR) in the aim of their biological evaluation. The antibacterial activity was tested against several bacteria strains, such as Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. The fungicide properties were evaluated against Candida albicans and C. krusei. The in vivo anti-inflammatory activity was studied on BIO:NMRI mice using the xylol-induced ear-edema test. Unfortunately, no antibacterial nor antifungal activity was exhibited by the grandiflorenic acid derivatives, but their anti-inflammatory activity revealed promising against acute inflammation, with the 9(11),16-dien-18-[2-(4-isobutylphenyl)propyl]- ent-kaurene being the best compound.
88

Produtos biológicos e alternativos no controle de doenças pós-colheita em melão cantaloupe / Products of biological and alternative in the control postharvest diseases of Cantaloupe melon

Moura, Renata Damasceno 05 May 2007 (has links)
Made available in DSpace on 2016-08-12T19:15:42Z (GMT). No. of bitstreams: 1 Renata DamascenoMoura.pdf: 1585836 bytes, checksum: 46aa646391a0b24176cc1eebf422215a (MD5) Previous issue date: 2007-05-05 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim this study was to evaluate the effect of the application of biological, alternative and chemical products on the control of postharvest diseases and conservation of Cantaloupe melon. In the control experiment in vitro (Test of Antagonist) was verified the ocorrence of antagonistic between isolates of Trichoderma (SN11, T15, T25, TR2) with relation the all pathogenic isolates to melon (Fusarium sp, Aspergillus niger, Aspergillus flavus, Rhizopus stlonifer and Lasiodiplodia theobromae). For the treatments, the most effective in the inhibition of the fungi mycelial growth were the nature fungicide 20 mL-1 and Lippia sidoides, that were effectives in 100% to all evaluated fungi; the Cymbopogum citratus was only less effective on the A. flavus fungi (75,3%) and the Imazalil fungicide has lower efficiency on the R stolonifer fungi (1,54%). The treatment with nature fungicide 2mL-1 has higher efficiency in relation to Fusarium sp and L. theobromae, with inhibitions of 88,9 and 86,2% respectively, and lower efficciency on the R. stolonifer (3,3%). In assay in vivo it was used split spot in a completely randomized design, with three replicates and three fruits for treatment. In the spots were alloted the periods of storage (0, 7, 14, 21 and 28 days) and the subplots, the treatments (Trichoderma + hipoclorito), (Trichoderma without hipoclorito), (nature fungicide 20 mL-1), (nature fungicide 2 mL-1), (essential oil of Cymbopogum citratus 2 mL-1), (essential oil of Lippia sidoides 2 mL-1), (Chemical Imazalil 1 mL-1) and (Control - application of destiled water). After the treatments, the fruits were conservated in boxes of paper, it using modify atmosphere with poliméricos films xtend and stored in a temperature of 6°C and UR 90±5%. The fruits were evaluated with relation to incidence of diseases, external and internal appearences, color, loss of matter fresh, pulp firmness, soluble solids, total soluble sugar, pH and titritable total acidity at 7, 14, 21 and 28 days after the period of storage of three days at 22º C ± 2º C and UR of 50% ± 5%. It was observed significant interation between treatments and storage time for occurence of disease, extern and intern appearence, color, titritable total acidity, pH and soluble solids. For the variable loss of fresch mass, it was verified that the treated fruits with nature fungicide 20 and 2 mL.L-1, Lippia sidoides and Cymbopogum citratus presented lower values, did not differing between them nor of the treatment with destiled water. The pulp firmness of treated fruits with Trichoderma (T1) presented value of 26,19 N and differed only of Trichoderma without hipoclorito (T2) and Cymbopogum citratus (T5), that showed fruits less firm (20,51 and 22,72 N, respectively). There was not statistical difference between treatments for the variables: soluble solids and total soluble sugar. The nature fungicide 20 mL1 Trichoderma with hipoclorito, Lippia sidoides and Imazalil were the treatments most effectives in the control of postharvest diseases of Cantaloupe hybrids melon ( Hy Mark ) / Objetivou-se estudar o efeito da aplicação de produtos biológicos, alternativos e químicos no controle de doenças pós-colheita e conservação de melões Cantaloupe. No ensaio de controle in vitro (Teste de Antagonismo) foi possível verificar a ocorrência de antagonismo entre os isolados de Trichoderma (SN11, T15, T25, TR2) em relação a todos os isolados patogênicos ao melão (Fusarium sp, Aspergillus niger, Aspergillus flavus, Rhizopus stlonifer e Lasiodiplodia theobromae). Quanto aos tratamentos os mais efetivos na inibição do crescimento micelial dos fungos foram o fungicida natural a 20. mL-1, e alecrim pimenta nos quais foram efetivos em 100% para todos os fungos avaliados, o capim citronela foi apenas menos efetivo sobre o fungo A. flavus (75,3%) e o fungicida Imazalil teve menor eficiência sobre o fungo R stolonifer (1,54%). O tratamento com fungicida natural a 2 mL-1teve maior eficiência em relação aos fungos Fusarium sp e L. theobromae, com inibições de 88,9 e 86,2 % respectivamente, e menor eficiência sobre o fungo R. stolonifer (3,3%). Para o experimento in vivo o delineamento experimental utilizado foi o inteiramente casualizado em parcelas subdivididas com três repetições e três frutos por tratamento. Nas parcelas foram alocados os períodos de armazenamento (0, 7, 14, 21, 28 dias) e nas subparcelas os seguintes tratamentos (Trichoderma + hipoclorito), (Trichoderma sem hipoclorito), (fungicida natural 20 mL-1), (fungicida natural 2 mL-1), (óleo essencial de capim citronela 2 mL-1), (óleo essencial de alecrim pimenta 2 mL-1), (Químico Imazalil 1mL-1) e (Testemunha- aplicação de água destilada). Após os tratamentos os frutos foram acondicionados em caixas de papelão, usando-se também atmosfera modificada com filmes poliméricos x-tend e armazenados sob refrigeração com temperatura de 6°C e UR 90±5%. As avaliações nos frutos foram realizadas para avaliação de doenças, aparência externa e interna, cor, perda de matéria fresca, firmeza de polpa, sólidos solúveis, açúcares solúveis totais, pH e acidez titulável realizadas a 7, 14, 21, e 28 dias após o período de prateleira de três dias a 22º C ± 2º C e UR de 50% ± 5%. Observou-se, interação significativa entre os tratamentos e o tempo de armazenamento para incidência de doença, aparência externa e interna, cor, acidez titulavel, pH, na relação sólidos solúveis e acidez titulavel. Para variável perda de massa fresca verificou-se que os frutos tratados com fungicida natural 20 e 2 mL.L-1, alecrim pimenta e capim citronela apresentaram os menores valores de perda de massa fresca, não diferindo entre si e nem do tratamento com água. Para firmeza de polpa frutos tratados com Trichoderma (T1) apresentaram firmeza entorno de 26,19 N, diferindo apenas de Trichoderma sem hipoclorito (T2) e capim citronela (T5) que proporcionaram frutos menos firmes 20,51 e 22,72 N respectivamente. Não foi observada diferença estatística entre os tratamentos pelo teste Tukey para as variáveis sólidos solúveis e açúcares solúveis totais. Os tratamentos que se mostraram mais efetivos no controle de doenças em pós-colheita do melão Cantaloupe híbrido Hy Mark foram fungicida natural a 20 mL1,Trichoderma com hipoclorito, alecrim pimenta e Imazalil
89

Produtos biológicos e alternativos no controle de doenças pós-colheita em melão cantaloupe / Products of biological and alternative in the control postharvest diseases of Cantaloupe melon

Moura, Renata Damasceno 05 May 2007 (has links)
Made available in DSpace on 2016-08-12T19:18:57Z (GMT). No. of bitstreams: 1 Renata DamascenoMoura.pdf: 1585836 bytes, checksum: 46aa646391a0b24176cc1eebf422215a (MD5) Previous issue date: 2007-05-05 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim this study was to evaluate the effect of the application of biological, alternative and chemical products on the control of postharvest diseases and conservation of Cantaloupe melon. In the control experiment in vitro (Test of Antagonist) was verified the ocorrence of antagonistic between isolates of Trichoderma (SN11, T15, T25, TR2) with relation the all pathogenic isolates to melon (Fusarium sp, Aspergillus niger, Aspergillus flavus, Rhizopus stlonifer and Lasiodiplodia theobromae). For the treatments, the most effective in the inhibition of the fungi mycelial growth were the nature fungicide 20 mL-1 and Lippia sidoides, that were effectives in 100% to all evaluated fungi; the Cymbopogum citratus was only less effective on the A. flavus fungi (75,3%) and the Imazalil fungicide has lower efficiency on the R stolonifer fungi (1,54%). The treatment with nature fungicide 2mL-1 has higher efficiency in relation to Fusarium sp and L. theobromae, with inhibitions of 88,9 and 86,2% respectively, and lower efficciency on the R. stolonifer (3,3%). In assay in vivo it was used split spot in a completely randomized design, with three replicates and three fruits for treatment. In the spots were alloted the periods of storage (0, 7, 14, 21 and 28 days) and the subplots, the treatments (Trichoderma + hipoclorito), (Trichoderma without hipoclorito), (nature fungicide 20 mL-1), (nature fungicide 2 mL-1), (essential oil of Cymbopogum citratus 2 mL-1), (essential oil of Lippia sidoides 2 mL-1), (Chemical Imazalil 1 mL-1) and (Control - application of destiled water). After the treatments, the fruits were conservated in boxes of paper, it using modify atmosphere with poliméricos films xtend and stored in a temperature of 6°C and UR 90±5%. The fruits were evaluated with relation to incidence of diseases, external and internal appearences, color, loss of matter fresh, pulp firmness, soluble solids, total soluble sugar, pH and titritable total acidity at 7, 14, 21 and 28 days after the period of storage of three days at 22º C ± 2º C and UR of 50% ± 5%. It was observed significant interation between treatments and storage time for occurence of disease, extern and intern appearence, color, titritable total acidity, pH and soluble solids. For the variable loss of fresch mass, it was verified that the treated fruits with nature fungicide 20 and 2 mL.L-1, Lippia sidoides and Cymbopogum citratus presented lower values, did not differing between them nor of the treatment with destiled water. The pulp firmness of treated fruits with Trichoderma (T1) presented value of 26,19 N and differed only of Trichoderma without hipoclorito (T2) and Cymbopogum citratus (T5), that showed fruits less firm (20,51 and 22,72 N, respectively). There was not statistical difference between treatments for the variables: soluble solids and total soluble sugar. The nature fungicide 20 mL1 Trichoderma with hipoclorito, Lippia sidoides and Imazalil were the treatments most effectives in the control of postharvest diseases of Cantaloupe hybrids melon ( Hy Mark ) / Objetivou-se estudar o efeito da aplicação de produtos biológicos, alternativos e químicos no controle de doenças pós-colheita e conservação de melões Cantaloupe. No ensaio de controle in vitro (Teste de Antagonismo) foi possível verificar a ocorrência de antagonismo entre os isolados de Trichoderma (SN11, T15, T25, TR2) em relação a todos os isolados patogênicos ao melão (Fusarium sp, Aspergillus niger, Aspergillus flavus, Rhizopus stlonifer e Lasiodiplodia theobromae). Quanto aos tratamentos os mais efetivos na inibição do crescimento micelial dos fungos foram o fungicida natural a 20. mL-1, e alecrim pimenta nos quais foram efetivos em 100% para todos os fungos avaliados, o capim citronela foi apenas menos efetivo sobre o fungo A. flavus (75,3%) e o fungicida Imazalil teve menor eficiência sobre o fungo R stolonifer (1,54%). O tratamento com fungicida natural a 2 mL-1teve maior eficiência em relação aos fungos Fusarium sp e L. theobromae, com inibições de 88,9 e 86,2 % respectivamente, e menor eficiência sobre o fungo R. stolonifer (3,3%). Para o experimento in vivo o delineamento experimental utilizado foi o inteiramente casualizado em parcelas subdivididas com três repetições e três frutos por tratamento. Nas parcelas foram alocados os períodos de armazenamento (0, 7, 14, 21, 28 dias) e nas subparcelas os seguintes tratamentos (Trichoderma + hipoclorito), (Trichoderma sem hipoclorito), (fungicida natural 20 mL-1), (fungicida natural 2 mL-1), (óleo essencial de capim citronela 2 mL-1), (óleo essencial de alecrim pimenta 2 mL-1), (Químico Imazalil 1mL-1) e (Testemunha- aplicação de água destilada). Após os tratamentos os frutos foram acondicionados em caixas de papelão, usando-se também atmosfera modificada com filmes poliméricos x-tend e armazenados sob refrigeração com temperatura de 6°C e UR 90±5%. As avaliações nos frutos foram realizadas para avaliação de doenças, aparência externa e interna, cor, perda de matéria fresca, firmeza de polpa, sólidos solúveis, açúcares solúveis totais, pH e acidez titulável realizadas a 7, 14, 21, e 28 dias após o período de prateleira de três dias a 22º C ± 2º C e UR de 50% ± 5%. Observou-se, interação significativa entre os tratamentos e o tempo de armazenamento para incidência de doença, aparência externa e interna, cor, acidez titulavel, pH, na relação sólidos solúveis e acidez titulavel. Para variável perda de massa fresca verificou-se que os frutos tratados com fungicida natural 20 e 2 mL.L-1, alecrim pimenta e capim citronela apresentaram os menores valores de perda de massa fresca, não diferindo entre si e nem do tratamento com água. Para firmeza de polpa frutos tratados com Trichoderma (T1) apresentaram firmeza entorno de 26,19 N, diferindo apenas de Trichoderma sem hipoclorito (T2) e capim citronela (T5) que proporcionaram frutos menos firmes 20,51 e 22,72 N respectivamente. Não foi observada diferença estatística entre os tratamentos pelo teste Tukey para as variáveis sólidos solúveis e açúcares solúveis totais. Os tratamentos que se mostraram mais efetivos no controle de doenças em pós-colheita do melão Cantaloupe híbrido Hy Mark foram fungicida natural a 20 mL1,Trichoderma com hipoclorito, alecrim pimenta e Imazalil
90

Remoção pela chuva de diferentes formulações de flutriafol aplicada em soja, com e sem a adição de óleo mineral na calda

Oliveira, Maria Aparecida Peres de [UNESP] 11 December 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-11Bitstream added on 2014-06-13T18:42:24Z : No. of bitstreams: 1 oliveira_map_dr_botfca.pdf: 804551 bytes, checksum: 700238b1422e359e397bc2e36724e08e (MD5) / Outros / O presente trabalho teve por objetivos verificar o efeito da remoção pela chuva de diferentes formulações de flutriafol, em condições de laboratório, aplicadas com e sem a adição de óleo na calda de pulverização, assim como verificar a influencia do óleo no espectro de gotas. O experimento considerou dez caldas resultantes da interação de cinco tratamentos contendo o flutriafol (quatro formulações de flutriafol isolado e uma mistura de flutriafol com tebuconazole), todas aplicadas com e sem óleo mineral. As dez caldas foram aplicadas sobre plantas de soja que receberam posteriormente lavagem por chuva simulada em laboratório com quatro intervalos de tempo entre a aplicação e a chuva. As chuvas foram simuladas em duas etapas, sendo uma lâmina inicial de 5 mm seguida de uma lâmina complementar de 15 mm. As coletas foram realizadas com quatro repetições, sendo cada uma delas constituída de um vaso com quatro plantas. A avaliação da concentração de flutriafol nas soluções resultantes da lavagem das plantas foi realizada através da quantificação dos resíduos do fungicida na água pelo método de cromatografia gasosa e espectrometria de massa (GCMS). Após a aplicação das caldas, as plantas foram retiradas do laboratório e deixadas à temperatura ambiente, a espera do tempo decorrido para a simulação da chuva, de acordo com cada tratamento. Após a simulação das lâminas de chuva as plantas foram cortadas dos vasos e lavadas em saco plástico contendo 200 mL de água destilada. Todas as lavagens foram realizadas em 4 intervalos: 0 h (no momento da aplicação), 1 h, 2 h e 48 h após a aplicação. Para o cálculo do percentual extraído, as quantidades de flutriafol nas soluções de lavagem foram comparadas à quantidade total depositada nas plantas, a qual foi representada... / The present study had for objectives to verify the effect of rainfastness of different flutriafol formulations, in laboratory conditions, applied with and without the oil adjuvant in the spray solution, as well as to verify the influence of the oil on the droplet spectrum. The experiment considered ten spray solutions related to five treatments containing flutriafol (four formulations of flutriafol and a flutriafol mixture with tebuconazole), all applied with and without mineral oil. The ten solutions were applied on soybean plants that were washed by simulated rainfall in laboratory with four time intervals between the application and the rainfall. Rainfall was simulated by one initial precipitation of 5 mm followed by a complementary 15 mm rainfall. Each vase with four plants was considered one replication. The washing solutions from the vases were collected and the flutriafol concentration on those solutions was evaluated through the quantification of the residues of the fungicide in the water using the Gas Chromatography-Mass Spectrometry (GC-MS). After the spray application the plants were removed of the laboratory and left to room temperature, the wait of the time elapsed for the simulation of the rain, in agreement with each treatment.After the simulated rain the plants were cut out of the vases and washed by immersion in plastic sack containing 200 mL of distilled water. All of the washing solutions (from the rain and the immersion process) were accomplished in 4 intervals: 0 h (in the moment of the spray application), 1 h, 2 h and 48 h after the application. For the calculation of the flutriafol extracted, the amounts of fungicide in the wash solutions were compared to the total amount deposited in the plants, which was represented by the sum of the amounts of the assets recovered in the washing... (Complete abstract click electronic access below)

Page generated in 0.0983 seconds