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In vitro and in vivo screening of Bacillus spp. for biological control of Rhizoctonia solani.Kubheka, Bongani Petros. January 2003 (has links)
The increasing concerns about chemical pesticides that are environmentally hazardous
and the continuous development of resistance by palhogens to chemical pesticides have
led to this study. Many studies have shown that some Gram-negative bacteria, such as
Pseudomonas flouresens, control plant diseases and promote plant growth. In this study
Gram positive bacteria, Bacillus sp., were chosen because of their ability to produce
endospores. Endospores can be used in stable, dry formulations. The advantage of using
endospores is their ability to survive harsh conditions such as droughts and high
temperatures, which give a long shelf life to the biological control agent.
Bacillus isolates were recovered from the rhizosphere of 12 different crops, and were
subsequently screened in vitro for their antimicrobial activity. Of 130 isolates, 87
exhibited antimicrobial activity against the test organisms: Rhizoctonia solani, Pythium
sp., Phytophthora cinnamoni, Fusarium sp., and single representatives of Gram negative
and Gram positive bacteria, namely, Erwinia carotovora and Staphylococcus aureus
respectively. The Bacillus isolates B77, B81 and B69 inhibited all the test organisms
investigated, which suggests that they produced broad spectrum antimicrobial compounds
or more than one antimicrobial compound. Of the isolates that showed antimicrobial
activity, 78 of them did not inhibit Trichoderma harzianum K D, which is a registered
biological control agent; indicating their potential for combined application.
Selected Bacillus isolates were tested for the biological control of R. solani under
greenhouse conditions in wheat, cabbage, tomato, maize, and cucumber seedlings.
Bacillus isolates were applied as seed treatments, and the inoculated seeds were planted
in R. solani infested speedling trays. Shoot dry weight measurement of seedlings
indicated that 12 out of 19 Bacillus isolates showed significantly different shoot dry
weight in wheat whereas all the isolates tested in tomato and cucumber gave significantly
different shoot dry weight. No significantly different shoot dry weight was obtained for
maize or cabbage. Seed emergence findings indicated that none of the Bacillus isolates
gave significantly different emergence percentage on wheat, cabbage, tomato, and maize
but all of them showed significantly different emergence percentage on cucumber. The
results indicate that both the pathogen and the biological control agents exhibited varying
levels of specificity on each crop tested.
The biological control potential of the best Bacillus isolates was tested on bean and maize
crops in the field. Green bean and maize seeds were coated with the selected Bacillus
isolates and then sown under field conditions. For each isolate, four replicate treatment
plots were established, with and without a R. solani inoculum. Percentage emergence,
plant survival levels to harvesting and yield of maize cobs and green beans pods were
measured. For all parameters measured the positive and negative controls were not
significantly different thereby rendering the results for the entire field study inconclusive.
However, Bacillus isolates B77, BII, R5 and R7 improved green bean pod yield and
Bacillus Isolate B8I increased maize yield, indicating their potentials as plant growth
promoting rhizobacteria (PGPR). / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
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Biological control and plant growth promotion by selected trichoderma and Bacillus species.Yobo, Kwasi Sackey. January 2005 (has links)
Various Trichoderma and Bacillus spp. have been documented as being antagonistic to a wide range of soilborne plant pathogens, as well as being plant growth stimulants. Successes in biological control and plant growth promotion research has led to the development of various Trichoderma and Bacillus products, which are available commercially. This study was conducted to evaluate the effect of six Trichoderma spp. and three Bacillus spp. and their respective combinations, for the biological control of Rhizoctonia solani damping-off of cucumber and plant growth promotion of dry bean (Phaseolus vulgaris L.). In vivo biological control and growth promotion studies were carried out under greenhouse and shadehouse conditions with the use of seed treatment as the method of application. In vitro and in vivo screening was undertaken to select the best Trichoderma isolates from 20 Trichoderma isolated from composted soil. For in vitro screening, dual culture bioassays were undertaken and assessed for antagonisms/antibiosis using the Bell test ratings and a proposed Invasive Ability rating based on a scale of 1-4 for possible mycoparasitic/hyperparasitic activity. The isolates were further screened in vivo under greenhouse conditions for antagonistic activity against R. solani damping-off of cucumber (Cucumis sativus L.) cv. Ashley seedlings. The data generated from the in vivo greenhouse screening with cucumber plants were analysed and grouped according to performance of isolates using Ward‟s Cluster Analysis based on a four cluster solution to select the best isolates in vivo. Isolates exhibiting marked mycoparasitism of R. solani (during ultrastructural studies) viz, T. atroviride SY3A and T. harzianum SYN, were found to be the best biological control agents in vivo with 62.50 and 60.06% control of R. solani damping-off of cucumber respectively. The in vitro mode of action of the commercial Trichoderma product, Eco-T®, and Bacillus B69 and B81 suggested the production of antimicrobial substances active against R. solani.
In vitro interaction studies on V8 tomato juice medium showed that the Trichoderma and Bacillus isolates did not antagonise each other, indicating the possibility of using the two organisms together for biological control and plant growth promotion studies. Greenhouse studies indicated that combined inoculation of T. atroviride SYN6 and Bacillus B69 gave the greatest plant growth promotion (43.0% over the uninoculated control) of bean seedlings in terms of seedling dry biomass. This was confirmed during in vivo rhizotron studies.
However, results obtained from two successive bean yield trials in the greenhouse did not correlate with the seedling trials. Moreover, no increase in protein or fat content of bean seed for selected treatments was observed. In the biological control trials with cucumber seedlings, none of the Trichoderma and Bacillus combinations was better than single inoculations of Eco-T®, T. atroviride SY3A and T. harzianum SYN. Under nutrient limiting conditions, dry bean plants treated with single and dual inoculations of Trichoderma and Bacillus isolates exhibited a greater photosynthetic efficiency that the unfertilized control plants. Bacillus B77, under nutrient limiting conditions, caused 126.0% increase in dry biomass of bean seedlings after a 35-day period. Nitrogen concentrations significantly increased in leaves of plants treated with Trichoderma-Bacillus isolates. However, no significant differences in potassium and calcium concentrations were found. Integrated control (i.e. combining chemical and biological treatments) of R. solani damping-off of cucumber seedlings proved successful. In vitro bioassays with three Rizolex® concentrations, viz., 0.01g.l-1, 0.1g.l-1 and 0.25g.l-1 indicated that the selected Trichoderma isolates were partly sensitive to these concentrations whereas the Bacillus isolates were not at all affected. In a greenhouse trial, up to 86% control was achieved by integrating 0.1g.l-1 Rizolex® with T. harzianum SYN, which was comparable to the full strength Rizolex® (1g.l-1) application. Irrespective of either a single or dual inoculations of Trichoderma and/or Bacillus isolates used, improved percentage seedling survival as achieved with the integrated system, indicating a synergistic effect. The results presented in this thesis further reinforce the concept of biological control by Trichoderma and Bacillus spp. as an alternative disease control strategy. Furthermore, this thesis forms a basis for Trichoderma-Bacillus interaction studies and proposes that the two organisms could be used together to enhance biological control and plant growth promotion. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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Biological control of Phytophthora root rot of citrus seedlings and cuttings.Abraham, Abraha Okbasillasie. January 2005 (has links)
With an increasing realization that many agrochemicals are hazardous to animals and humans, came the desire to replace these chemical agents with biological approaches that are more friendly to the environment and human health. Microorganisms play an important role in plant disease control, as naturally occurring antagonists. Microorganisms may also have beneficial
effects on plant development when applied to plant roots. Research efforts worldwide have recorded successes in biological control and growth stimulation on many crops, particularly when using members of the genera Bacillus and Trichoderma. Their use on citrus rootstock could be advantageous to nurserymen and growers in reducing the incidence of seedling mortality and increasing production. To achieve these objectives, laboratory and tunnel experiments were conducted to develop effective biocontrol agents for citrus seedlings and cuttings. Nineteen 0 ut 0 f 23 Trichoderma isolates tested in vitro against Phytophthora p arasitica sp
showed antagonistic activity by hyperparasitism and four out of eight Bacillus isolates resulted in antagonism by forming inhibition zones. The positive in vitro activity of Trichoderma and Bacillus isolates on Phytophthora provided motivation step for further trials in the greenhouse to evaluate their biological control activity on citrus seedlings and cuttings. A greenhouse trial was carried out to evaluate the biological control potential of 23 Trichoderma isolates (drenched at 5 x 105 spores / rnI) and two Bacillus isolates (drenched at 1 X 106 or 1 X 108 colony forming units (CFU) / rnI) to suppress Phytophthora parasitica sp. of rough lemon (Citrus jambhirini Lush.) seedlings. Five isolates ofTrichoderma (AA12, AA5, Trichoderma harzianum (AA16), SY3F and Eco-T~ were highly effective in suppressing Phytophthora root rot, with AA12 providing the best control. The Bacillus isolates also suppressed the pathogen but were not as effective as the Trichoderma isolates. This trial was used to test for growth stimulation activity by some of the biocontrol agents. To verify these results, a further trial was carried out to evaluate growth stimulation capabilities in the absence of any pathogen. Trichoderma Isolates AA13 and AA17 caused no 111 change in seedling growth, while other Trichoderma and Bacillus isolates had an inhibitory effect on the seedling growth. This trial indicated that the biocontrol activity was affected by
inoculum densities, and as a result in vitro sporulation capacity was evaluated. TrichodermaIsolate AA16 was the largest spore producer, followed by Eco-T®. Spore production was lowest from Trichoderma isolates AA4 and AA12. Growth stimulation responses of Trichoderma Isolates AA4, AA16, Eco-TID and SYN6 were further studied at four different doses (1 X 103, 1 X 104, 5 X 105 or 1 X 106 spores / ml) on rough lemon and trifoliate orange seedlings. Trifoliate oranges responded positively to 1 X 104 and 5 X 105 spores / ml of Eco-TID, but rough lemon responded negatively to all dosages of the Trichoderma isolates applied. This indicates that the inoculum density responses may be host specific. Higher population density of 1 X 106 spores / ml of all tested Trichoderma isolates had a stunting effect on seedling growth of both species. Based on t he positive results 0 f individual applications of some Trichoderma and Bacillus isolates, of the biological control agents on rough lemon seedlings against Phytophthora
parasitica in an earlier greenhouse trial, their combined effect in the control of the pathogen was performed. Before carrying out a greenhouse trial, activities of the isolates to be combined were evaluated in vitro. This trial showed that Trichoderma Isolates AA16 and Eco-T®were compatible. Trichoderma isolates AA16 and Eco-T®were also found to be compatible with
Bacillus Isolates B77, B81 and PHP. As a result, further in vivo trials were conducted. The tunnel trials were carried out as two separate experiments:
In the first experiment, a combination of two Trichoderma Isolates A A 16 and Eco-T®was conducted assayed at 5 X 105 or 1 X 106 spores / ml, on rough lemon seedling, and cuttings and trifoliate orange and sour orange seedlings. A combination of Trichoderma isolate AA16 and Eco-T®at 5 X 105 spore / ml increased significantly the new flush biomass of rough lemon cuttings compared to AA16 alone, but was not different from Eco-TID alone. The combination of AA16 and Eco-T® achieved no change of biomass of rough lemon and trifoliate orange seedlings. The combination of AA16 and Eco-TID did not increase the root biomass of sour orange compared to AA16 or Eco-r® alone. The combination of AA16 and Eco-r® at higher doses (1 x 106 spores / ml) showed significantly better suppression of Phytophthora root rot of rough lemon cuttings but did not show disease suppression in all seedling species verities tested. In a second experiment, individual and combined effects of Trichoderma isolates (drenched at 5 X 105 spores / ml) with Bacillus isolate (drenched at 1 X 106 colony forming units (CFU) / ml) for suppression of Phytophthora root rot on rough lemon and trifoliate orange seedlings was performed. The combination of Trichoderma Isolate AA16 and Bacillus Isolate B81 increased root biomass on rough lemon seedlings compared to the combination of Trichoderma AAI6 or Bacillus PHP but was not significantly different to Trichoderma AA16 alone. Bacillus PHP combined with Trichoderma AA16 or singly had no effect on rough lemon seedlings. Combining Trichoderma Eco--r® and with Bacillus B8I or PHP did not increase biomass of rough lemon seedlings compared to Trichoderma Isolate Eco--r® alone. There was no statistically significant differences in the effects of the combinations of the Trichoderma and Bacillus isolates compared to their individual applications on the biomass of trifoliate oranges. This study established the antagonistic potential of several South African isolates of
Trichoderma and Bacillus as a viable alternative to agrochemicals for controlling Phytophthora parasitica. The growth stimulation capabilities of Trichoderma isolates in terms of seedling development was also demonstrated. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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Metal enhanced detection of salivary proteins, Bacillus globigii and novel reagents for bioimaging & sensingAluoch, Austin Ochieng. January 2007 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry, 2007. / Includes bibliographical references.
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The development of a putative microbial product for use in crop production /Gumede, Halalisani. January 2008 (has links)
Thesis (M.Sc. (Biochemistry, Microbiology & Biotechnology)) - Rhodes University, 2008.
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Versatilidade de Bacillus spp. no controle biológico de doenças de plantas e na promoção de crescimento de soja /Dorighello, Dalton Vinicio, 1985- January 2017 (has links)
Orientador: Wagner Bettiol / Banca: Antonio Carlos Maringoni / Banca: Carlos Gilberto Raetano / Banca: Regina Maria Villas Boas de Campos Leite / Banca: Marcelo Augusto Boechat Morandi / Resumo: O mercado de produtos de controle biológico, principalmente os que possuem isolados de Bacillus spp. em sua formulação, tem aumentado significativamente, devido às exigências de diminuição do uso de agrotóxicos e maior sustentabilidade do segmento agrícola. Assim, o presente trabalho teve por objetivos: 1- Avaliar o potencial de bactérias do gênero Bacillus no controle de diferentes doenças de plantas; 2- Selecionar isolados de Bacillus spp. promotores de crescimento da soja e antagonistas a Sclerotinia sclerotiorium; 3- Avaliar o potencial de um produto comercial à base de B. subtilis QST 713 e outro à base de óleo de café torrado para compor um programa de manejo da ferrugem-asiática da soja (Phakopsora pachyrhizi) em aplicação sequencial ou alternada com um fungicida. Inicialmente foi avaliado o efeito de B. subtilis, B. firmus e B. amyloliquefaciens no controle dos patógenos Erysiphe diffusa, Podosphaera xanthii, Sclerotinia sclerotiorum, P. pachyrhizi, Fusarium solani, Fusarium oxysporum f. sp. phaseoli, Colletotrichum lindemuthianum e Corynespora cassiicola em condições controladas. Neste estudo, nenhum dos isolados controlou Erysiphe difusa e Podosphaera xanthii. Em folhas destacadas, todos os isolados reduziram o diâmetro da lesão de S. sclerotiorum e a severidade de P. pachyrhizi, sendo mais efetivos com aplicação preventiva. B. subtilis, B. firmus e B. amyloliquefaciens também inibiram o desenvolvimento de F. oxysporum f. sp. phaseoli, C. cassiicola e C. lindemuthia... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The market of products for biological control, especially formulations using Bacillus spp., has increased significantly, due to the requirements for the reduction of the use of agrochemicals in crop protection and sustainability of the agricultural sector. The objectives of this thesis were: 1- To evaluate the potential of Bacillus in plant disease control; 2- To select isolates of Bacillus spp. for growth promotion of soybean and antagonists to Sclerotinia sclerotiorium; 3- To evaluate the potential of a commercial product based on B. subtilis QST 713 and another product based on roasted coffee oil in order to compose a management program for asian soybean rust (Phakopsora pachyrhizi) in sequential or alternating application with a fungicide. Initially, the effect of B. subtilis, B. firmus and B. amyloliquefaciens on the control of pathogens Erysiphe diffusa, Podosphaera xanthii, Sclerotinia sclerotiorum, P. pachyrhizi, Fusarium solani, Fusarium oxysporum f. sp. phaseoli, Colletotrichum lindemuthianum and Corynespora cassiicola was evaluated under controlled conditions. In this study, Bacillus isolates did not controlled Erysiphe diffusa and Podosphaera xanthii. All isolates were effective in reducing the diameter of the S. sclerotiorum lesion and the severity of P. pachyrhizi, being more effective by preventive application in detached leaf. B. subtilis, B. firmus and B. amyloliquefaciens inhibited the mycelial growth of F. oxysporum f. sp. phaseoli, C. cassiicola and C. lindemuthianum ... / Doutor
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Aislamiento y caracterización de cepas nativas de Bacillus spp y Trichoderma spp de la rizosfera de cafeto con potencial antagonista frente a Fusarium oxysporum del valle de Monzón – Huánuco-PerúDíaz Camezán, Yohana Lisset January 2019 (has links)
El cafeto (Coffea arábica, L.) es uno de los principales productos de la canasta agroexportadora peruana, hecho que ha contribuido con el desarrollo económico y social del Perú. Sin embargo este se ve afectado por enfermedades fúngicas como la pudrición vascular causado por Fusarium oxysporum, reduciendo el sistema radicular en más de 90% afectando la producción y calidad. Por ello, se busca aislar cepas nativas de Bacillus y Trichoderma de rizósfera de café con capacidad antagonista frente a Fusarium oxysporum que puedan utilizarse en programa de manejo integrado de plagas del cafeto, en el distrito de Monzón, región Huánuco. Se logró aislar 30 cepas de Bacillus ssp. y 20 cepas de Trichoderma spp las mismas que fueron evaluadas por su capacidad antagonista frente al patógeno F. oxysporum, siguiendo la metodología de enfrentamiento directo dual en el medio Agar Papa Dextrosa . Se realizó pruebas bioquímicas, caracterización macroscopica y microscópica a las cepas con actividad antagonista y se identificó por claves taxonómicas. Las 9 cepas de Trichoderma (M3PI.I, B1.T, MTS.I, MT5.A, MT12.A, PLSO1, TL7.R, MT24.I, MT14.e) y 6 cepas de Bacillus (MT1.I, MT1.II, MT2.I, MT2.II, MT7, MT3P3) con actividad antagonista; siendo la cepa M3PI.I la que alcanzó 80 % de actividad de inhibición del fitopatogeno. Las cepas con mayor actividad antagonista (MT3P3, B1.T, MTS.I) fueron identificadas molecularmente como Trichoderma sp, Trichoderma asperellum, Trichoderma sp respectivamente. Las cepas aisladas de Bacillus sp y Trichoderma sp podrían considerarse como potenciales biocontroladores de pudrición vascular en cafeto representando una nueva vía de trabajo en pro de una agricultura sostenible. / Tesis
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Aislamiento y caracterización fenotípica y molecular de cepas nativas de Bacillus thuringiensis aisladas de ecoregiones de la costa del Perú con actividad larvicida para Aedes (Stegomyia) aegypti (L)Ramirez Ortiz, Ingrid Nathalie January 2019 (has links)
Aedes aegypti es un vector de enfermedades de importancia en salud pública que es controlado con insecticidas químicos, sin embargo la naturaleza de estos insecticidas generan daños al ambiente y al hombre, además de generar resistencia entre las poblaciones de mosquitos. El objetivo de la presente investigación fue aislar y caracterizar cepas nativas de Bacillus thuringiensis con actividad larvicida frente a Aedes aegypti que puedan ser utilizadas como controladores biológicos de éste mosquito vector, y ser una alternativa más ecológica frente al uso de los insecticidas químicos. Las cepas fueron aisladas de tres ecorregiones costeras del Perú, las que fueron caracterizadas a través de pruebas bioquímicas diferenciales, observación de cristales parasporales y caracterizadas molecularmente a través de la detección de genes cry4Aa, cry11Aa y cyt1Aa. La actividad larvicida de las cepas nativas fue determinada siguiendo la metodología descrita por la OMS (2005), y utilizando la cepa B. thuringiensis HD500 como patrón. De las ecorregiones de Piura, Chiclayo y Lima se aislaron 9 cepas nativas de Bacillus thuringiensis, de las cuales 3 mostraron alta toxicidad para larvas del tercer estadío de Aedes aegypti. Estas cepas mostraron cristales parasporales circulares, pruebas bioquímicas características de Bacillus thuringiensis y la posesión genes cry11Aa y cyt1Aa para dos de las cepas nativas y la presencia de todos los genes evaluados para una cepa nativa. / Tesis
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Biological control of the common house fly (Musa domestica L.) using Bacillus thuringiensis (Ishiwata) berliner var. Israelensis and Beauveria bassiana (Bals.) vullemin in caged poultry facilities.Mwamburi, Lizzy A. January 2008 (has links)
The entomopathogenic fungus Beauveria bassiana and the bacterium Bacillus thuringiensis var. israelensis (Bti) have been widely studied for their role in biocontrol against many arthropods and extensively exploited for insect pest control. The purpose of this study was to evaluate the effect of four B. bassiana and two Bti formulations and their respective combinations, for the biological control of the common house fly, Musca domestica L., a major pest in poultry facilities. In vitro screening was undertaken to select the best B. bassiana isolates from 34 B. bassiana isolates and two Paecilomyces isolates. All the isolates of B. bassiana were found to be effective against adult house flies, but were marginally effective in controlling fly larvae. The Paecilomyces isolates were non-pathogenic towards both adult house flies and larvae. The best four isolates R444, 7320, 7569 and 7771 caused >90% mortality within 2d and were subjected to dose-mortality bioassays. Microscopic studies using light and scanning electron microscopy indicated the different durations of the lifecycle of B. bassiana development on the house fly. High temperature was found to delay conidial germination. Spore germination and mycelial growth were also inhibited by high adjuvant concentrations. Laboratory baseline bioassay data established, a dose-time response relationship using a waterdispersible granules (WDG) Bti formulation that demonstrated that the susceptibility of M. domestica larvae to a given concentration of Bti increased as the duration of exposure increased. In the laboratory studies, the LC50 and LC90 values of Bti for the larvae ranged between 65 - 77.4 and 185.1 - 225.9?g ml-1, respectively. LT50 and LT90 values were 5.5 and 10.3d respectively. In the field, a concentration of 10g Bti kg-1 (bran formulation) of feed resulted in 90% reduction of larvae for 4wk post-treatment. A higher concentration (2g L-1) of Bti in spray (WDG) applications was not significantly more effective than the lower concentration of 1g L-1. Thus, adding Bti to chicken feed has potential for the management and control of house flies in cagedpoultry facilities. The impact of oral feed applications of a bran formulation of Bti and a commercial chemical larvicide, Larvadex®, were compared with respect to their efficacy on the control of house fly 3 larval populations in poultry manure. The sublethal effects were manifested in terms of decreasing emergence of adult house flies. Although Larvadex® reduced larval density and caused significant reductions in emergence of adult house flies, it generally exhibited weaker lethal effects than Bti. The reduction levels achieved as a result of feeding 250mg Bti kg-1 at 5wk were similar to those achieved as a result of feeding twice the amount of Larvadex® at 4wk to the layers. From both an efficiency and economic perspective, comparisons to assess the impact of combining different concentrations of the two Bti formulations were carried out to evaluate their success in controlling house fly larvae and adults in poultry houses. The percentage mortality of larvae accomplished as a result of using a combination of 250mg kg-1 Bti in feed and 2g L-1 spray applications was equivalent to that obtained as a result of combining 500mg kg-1 Bti in feed and 1g L-1 spray application. The cost-benefit analysis (expressed in terms of mortality of larvae) indicated that the most effective combination for control of house fly larvae and fly emergence was the 500mg kg-1 in feed and 2g L-1 spray application combination that resulted in 67% larval mortality and 74% inhibition of adult house fly emergence. This study presents commercial users with possible combinations of applications of the two Bti formulations. Comparisons of larval mortalities and house fly emergence resulting from the Bti - B. bassiana treatments with those from Larvadex® - B. bassiana treatments, showed better control levels compared to any of the individual agents alone. The Bti treatments were more effective at controlling larval populations and inhibiting the emergence of house flies than Larvadex®, even when Larvadex® was applied together with B. bassiana. The effects of the Bti - B. bassiana and the Larvadex® - B. bassiana interactions were additive. These trials suggest that the efficacy of Bti in the control of house fly larvae may be improved with frequent applications of B. bassiana. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
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Espécies de Bacillus no controle de Meloidogyne incógnita e Meloidogyne javanica in vitro e na cana-de-açúcarFerreira, Rivanildo Junior [UNESP] 20 February 2015 (has links) (PDF)
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000829026.pdf: 336457 bytes, checksum: 8b02bbfade913853e331d4f14b9e3cc1 (MD5) / A cultura de cana-de-açúcar é de grande importância para a economia brasileira. Os fitonematoides são um dos fatores limitantes na maioria dos canaviais causando grandes perdas à cultura. O manejo dos nematoides é feito através de nematicidas químicos que são prejudiciais ao homem, meio ambiente e produtos colhidos, devido sua alta toxicidade. O controle biológico tem sido uma alternativa viável e sustentável para o manejo dos nematoides. O objetivo do presente trabalho foi avaliar espécies de Bacillus no controle de Meloidogyne incognita e M. javanica in vitro e na cana-de-açúcar. Foram instalados experimentos em condições de laboratório com delineamento inteiramente casualizado com os tratamentos: Cadusafós 200 CS (14 L/ha); B. subtillis; B. firmus e B. amyloliquefaciens (1 e 10 L/ha), além de uma testemunha (água). Os ensaios em vasos, à céu aberto, tiveram delineamento inteiramente casualizado, com os tratamentos B. subtilis (10 L/ha), B. firmus (10 L/ha), B. amyloliquefaciens (10 L/ha), Carbofurano 350 SC (5 L/ha - tratamento padrão) e uma testemunha, com cinco repetições e duas avaliações (100 e 150 dias após inoculação e aplicação dos tratamentos). No ensaio in vitro, B. firmus (10 L/ha) é o mais eficiente para diminuir a eclosão de J2 de M. javanica, sendo estasticamente semelhante ao produto químico testado. Quanto a motilidade de J2 de M. javanica, B. subtilis (10 L/ha) e B. amyloliquefaciens (1 e 10 L/ha), causam a mortalidade do nematoide, porém inferior ao padrão químico testado. Para M. incognita, B. firmus (10 L/ha) proporciona maior eclosão de J2. Quanto a motilidade de J2 de M. incognita, Cadusafós 200 CS (14 L/ha) causou a maior mortalidade. Nos ensaios em vasos, todos os tratamentos aumentam o número de perfilhos, mas não controlam os nematoides / The sugar-cane crop is very important to Brazilian economy. Phytonematodes are among the main limitating factors of such culture causing great losses. Chemical nematicides are harmful to humans, environment, harvested products, and are the main method used to manage the populations of these nematodes. Biological control have been a sustainable alternative to manage these nematodes. The aim of the present study was to evaluate Bacillus species for control Meloidogyne incognita and M. javanica in vitro and in sugar cane plants. We set assays in laboratory conditions in a completely random design with the treatments: Cadusafós 200 CS (14 L/ha), B. subitilis, B. firmus, B. amyloliquefaciens (1 and 10 L/ha) and a control (water). The pot assay, in a semi-field condition, had a completely random design with the treatments: B. subtilis (10 L/ha), B. firmus (10 L/ha), B. amyloliquefaciens (10 L/ha), Carbofurano 350 SC, with five replicates and two evaluation periods (100 and 150 days after inculation and application of treatments). At laboratory assay B. firmus (10 L/ha) was the most efficient in decreasing the M. javanica J2 eclosion and were statistically similar to the chemical nematicide tested. For M. javanica J2 mobility, B. subtilis (10 L/ha) and B. amyloliquefaciens (1 and 10 L/ha) cause nematode mortality, but lower than that presented by the chemical. To M. incognita, B. firmus (10 L/ha) provides higher J2 eclosion. For the M. incognita J2 mobility, Cadusafos 200CS (14 L/ha) caused higher mortality. In the pot assay, all treatments increase the number of tillers but do not control the nematodes
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