Everaldo Antônio Lopes

{null=Cover crops and Pochonia chlamydosporia for the control of Meloidogyne javanica, en=Cover crops and Pochonia chlamydosporia for the control of Meloidogyne javanica }

{null=The objective of this research was to evaluate the effect of the combination of Pochonia chlamydosporia var. chlamydosporia with summer and winter cover plants on the control of Meloidogyne javanica on tomato plants under glasshouse conditions. Treatment combinations were with four soil covers (pearl millet and Surinam grass in Experiment 1, oil radish and black oat in Experiment 2; plus tomato and fallow controls) and two P. chlamydosporia treatments (with or without the fungus). The antagonist was applied to nematode-infested soil when the cover crops or tomato were planted. Tomato plants were removed and the above-ground parts of the cover crops were cut, dried, and placed on the pots 60 days after planting. One tomato seedling was transplanted in each pot in a no-tillage system and cultivated for 60 days. Surinam grass, pearl millet and black oat reduced galls and eggs of M. javanica by more than 90%, without application of the fungus. However, P. chlamydosporia + Surinam grass significantly reduced by 72% the number of galls compared with cultivation of the grass in soil without the fungus. Pochonia chlamydosporia became established in soil and could be re-isolated at the end of both experiments. Colony forming units (CFU) (g soil)–1 varied from 1.0 × 105 (fallow) to 2.6 × 105 (pearl millet) and from 1.1 × 105 (fallow) to 2.3 × 105 (oil radish) for the experiments with summer soil cover crops and winter soil cover crops, respectively. The cultivation of Surinam grass, pearl millet and black oat reduced M. javanica populations, and the combination with P. chlamydosporia may favour the establishment of the fungus in the soil and enhance the control of the nematode., en= The objective of this research was to evaluate the effect of the combination of Pochonia chlamydosporia var. chlamydosporia with summer and winter cover plants on the control of Meloidogyne javanica on tomato plants under glasshouse conditions. Treatment combinations were with four soil covers (pearl millet and Surinam grass in Experiment 1, oil radish and black oat in Experiment 2; plus tomato and fallow controls) and two P. chlamydosporia treatments (with or without the fungus). The antagonist was applied to nematode-infested soil when the cover crops or tomato were planted. Tomato plants were removed and the above-ground parts of the cover crops were cut, dried, and placed on the pots 60 days after planting. One tomato seedling was transplanted in each pot in a no-tillage system and cultivated for 60 days. Surinam grass, pearl millet and black oat reduced galls and eggs of M. javanica by more than 90%, without application of the fungus. However, P. chlamydosporia+Surinam grass significantly reduced by 72% the number of galls compared with cultivation of the grass in soil without the fungus. Pochonia chlamydosporia became established in soil and could be re-isolated at the end of both experiments. Colony forming units (CFU) (g soil)−1 varied from 1.0×105 (fallow) to 2.6×105 (pearl millet) and from 1.1×105 (fallow) to 2.3×105 (oil radish) for the experiments with summer soil cover crops and winter soil cover crops, respectively. The cultivation of Surinam grass, pearl millet and black oat reduced M. javanica populations, and the combination with P. chlamydosporia may favour the establishment of the fungus in the soil and enhance the control of the nematode. }

Avaliação de Extratos Aquosos de Espécies Vegetais, Aplicados Via Pulverização Foliar, Sobre Meloidogyne javanica

Departamento de Fitopatologia, Universidade Federal de Vicosa, CEP 36570-000, Vicosa-MG, Brasil. E-mail: cris_gardiano@yahoo.com.brAutor para correspondencia: Cristiane Goncalves GardianoData de chegada: 14/08/2007. Aceito para publicacao em: 30/06/20081523Diversos compostos com potencial nematicida podem ser obtidosa partir de plantas. Entretanto, a aplicacao de tais extratos,principalmente na forma de pulverizacao sobre a parte aerea, vemsendo pouco estudada para o controle deste patogeno. Desta forma, oobjetivo do trabalho foi avaliar a atividade nematicida sistemica dosprincipios ativos encontrados em especies de plantas, via pulverizacaofoliar dos extratos aquosos, sobre

Pochonia chlamydosporia var. chlamydosporia (Goddard) Zare & W. Gams for the management of lettuce infected with Meloidogyne javanica (Treub, 1885)

The application of the nematophagous fungus Pochonia chlamydosporia var. chlamydosporia (Goddard) Zare & W. Gams during seedling production of vegetable crops can be an efficient approach to control root-knot nematode. The aim of this study was to evaluate the effect of treating seedlings and/or soil with bionematicide (wettable powder formulation) based on chlamydospores from isolate Pc-10 on the Meloidogyne javanica (Treub, 1885) control in lettuce (Lactuca sativa L.). Isolate Pc-10 was diluted in water and applied when watering the seedlings (0, 4.5, 9.0, 13.5, and 18.0 g L-1) and/or to the potted soil (5000 chlamydospores g-1) used for growing lettuce. The soil in each pot was infested with 3000 M. javanica eggs. The number of M. javanica eggs was reduced in lettuce roots when isolate Pc-10 was applied either to seedlings or soil; there was no interaction between application methods. The decrease in the number of eggs was proportional to the increase of isolate Pc-10 applied to seedlings with maximum reduction of 43.5% at the 18 g L-1 dose. When the fungus was applied to the soil, the number of eggs was reduced by 12.3%. Increasing doses of isolate Pc-10 reduced the number of galls up to 21% with the 18 g L-1 dose. Applying bionematicide based on P. chlamydosporia isolate Pc-10 at 18 g L-1 on seedlings controls M. javanica in lettuce.

Evaluation of plant aqueous extracts, added into the soil, on Meloidogyne javanica (Treub, 1885) Chitwood, 1949.

O uso de extratos vegetais com propriedades nematicidas no controle de fitonematoides representa mais uma alternativa para os pequenos produtores, com valor pratico e economico, e sem riscos de contaminacao do ambiente. A adicao ao solo dos extratos aquosos de 20 especies de plantas foi avaliada sobre a populacao de Meloidogyne javanica em plantas de tomateiro, em casa de vegetacao. Estas foram divididas em dois grupos e avaliadas em dois experimentos separados. No mesmo dia em que se infestou o solo com 5.000 ovos do nematoide, adicionou-se 20 mL dos extratos aquosos obtidos de folhas de artemisia ( Chrysanthemum parthenium ), bardana ( Arctium lappa ), capim cidreira ( Cymbopogon citratus ), carqueja ( Bacharis trimera ), cavalinha ( Equisetum sp.), cinamomo ( Melia azedarach ), hortela ( Mentha sp.), mamona ( Ricinus communis ), manjericao ( Ocimum basilicum ), melao-de-Sao-Caetano ( Momordica charantia ), arruda ( Ruta graveolens ), falso-boldo ( Coleus barbatus ), confrei ( Symphitum officinalis ), erva-de-bicho ( Polygonum acre ), feijao-de-porco ( Canavalia ensiformis ), funcho ( Foeniculum vulgare ), guine ( Petiveria alliacea ), mentrasto ( Ageratum conyzoides ), mucuna-cinza ( Mucuna pruriens ) e nim ( Azadirachta indica ). Agua destilada foi adicionada ao solo como tratamento testemunha. Apos 60 dias, avaliou-se a altura das plantas, o peso fresco da parte aerea e da raiz e os numeros de galhas e de ovos por sistema radicular. Os extratos de hortela, bardana e mamona reduziram o numero de galhas em 75,6%, 65,7% e 54,4%, e o numero de ovos em 81,7%, 75,9% e 56,6%, respectivamente.

Incorporação ao solo de substrato contendo micélio e conídios de Pochonia chlamydosporia para o manejo de Meloidogyne javanica

Chlamydospores are the main propagules used as source of inoculum of Pochonia chlamydosporia in biocontrol experiments of root-knot nematodes. The objective of this study was to evaluate the control of Meloidogyne javanica on tomato plants by the soil application of rice grains colonized by Pochonia chlamydosporia containing just mycelium and conidia, without chlamydospores. The fungus (isolate Pc-10) was grown for 15 days at 26°C on grains of rice, previously sterilized in microwave oven. Two experiments were simultaneously carried out under greenhouse conditions. In the experiment 1, 2-L pots were filled with a soil:sand mixture (1:1, v:v) containing 3g kg-1 of soil of rice grains colonized by the antagonist. In the experiment 2, the fungus was added into the soil of 0.5L pots at the doses of 5, 10, 15, 20, 25 or 30g kg-1 of soil. The soil of each pot was infested with 4,000 eggs of M. javanica and one tomato seedling was transplanted in each pot after fifteen days. In the experiment 1, the application of the fungus into the soil reduced the number of galls and eggs of the nematode by 40% and 72.83%, respectively. In the experiment 2, it was observed the reduction of the number of eggs from the dose of 5 g kg-1 of soil and of the number of galls, particularly at the doses of 25 and 30g kg-1 of soil. As a conclusion, P. chlamydosporia controlled M. javanica on tomato plants even when applied into the soil as colonized-rice grains and without chlamydospores.

Ação nematicida do eugenol em tomateiro

Essential oils from several plant species have nematicidal properties and could be used for controlling root-knot nematodes. Thus, this study aimed at evaluating the effect of eugenol concentrations on the control of Meloidogyne incognita and Meloidogyne javanica , in a greenhouse. The eugenol was applied at the concentrations of 0.25 mL L -1 , 0.5 mL L -1 , 0.75 mL L -1 and 1.0 mL L -1 , as a foliar spray or soil drench. A complete randomized design, in a 4 x 2 + 1 factorial scheme (concentrations of eugenol x methods of application + control – additional treatment), with five replications, was used. The number of galls and eggs of M. incognita and eggs of M. javanica decreased in plants treated with eugenol, when compared to the control. Soil drench was the most efficient method for applying eugenol, regarding the reduction in the number of galls. Increasing concentrations of eugenol reduced the number of M. incognita eggs. Eugenol showed potential to be used in the management of root-knot nematodes, though further studies are necessary to support such an expectation.

Interactions Between Pochonia chlamydosporia and Nematodes

Pochonia parasitizes the eggs and females of plant-parasitic nematodes (PPN). The fungus-nematode interaction involves a complex series of events which can be affected by the environment. Thus, an understanding of the bionomics of this interaction is essential in order to improve the efficiency of the biological management of PPN. In this chapter, we provide an overview of the process of infection of nematodes by Pochonia and the role of the environment on the fungus-nematode interaction. Firstly, we focus on the events and the mechanisms underlying adhesion, penetration and colonisation of nematodes by Pochonia. We discuss how the infection process is driven by both mechanical forces, induced by the appressoria, and enzymatic activity, specifically by the serine proteases (P32, VCP1, SCP1) and chitinases. Environmental factors have a profound influence on the Pochonia-nematode interaction and these are discussed in detail. Temperature, pH, soil type, soil microbiota and roots can enhance or reduce the parasitism of the nematode by the fungal antagonist. Finally, we discuss how the method of application of Pochonia and its timing can impact on the establishment of the fungus in the soil and, consequently, on the control of nematodes.

COMBINATION OF ISOLATES OF Pochonia chlamydosporia FOR THE CONTROL OF Meloidogyne javanica IN TOMATO

Three different isolates of Pochonia chlamydosporia (Pc-3, Pc-10 and Pc-28) were evaluated in a greenhouse experiment when applied individually and in combinations. A control treatment with no application of isolates of P. chlamydosporia var. chlamydosporia was included, while neither isolates nor nematodes were used in another untreated treatment. One-liter pots were filled with sterilized soil, and each pot was infested with 3 g of rice substrate colonized with the respective isolate plus 3,000 eggs of Meloidogyne javanica. One ‘Santa Clara’ tomato seedling was transplanted to each pot after fifteen days. None of the isolates (applied individually or in combinations) was able to reduce the number of galls when compared to the control treatment. However, the number of eggs of M. javanica decreased for isolates Pc-10 and mixtures Pc-10 + Pc-3, and Pc-10 + Pc-28 + Pc-3. The association of isolates of P. chlamydosporia var. chlamydosporia did not increase the control of M. javanica when compared to the application of Pc-10 individually.

Formulation of bionematicides based on bacteria for the control of the lesion nematode in common bean

espanolBacterias del genero Bacillus pueden suprimirpoblaciones de nematodosfitoparasitos. Sobre la base de esta hipotesis, ocho cepas de Bacillus (SF262, SF264, SF266, SF267, SF268, SF271, SF292 y SF 629)fueronformuladas y aplicadas en el tratamiento de semillas y en la superficie de suelo para el control de Pratylenchus brachyurus en frijol. La aplicacion de las cepas no aumentaron la produccion de granos y la masa de las raices, ni redujeron el numero de nematodos en el suelo y en las raices. Asi, ninguna de las cepas de Bacillus es promisoria para el control del nematodo lesionador en frijol. EnglishBacteria belonging to the genus Bacillus can promote plant growth and suppress plant-parasitic nematode populations. Based on this hypothesis, eight strains of the bacterium (SF 262, SF 264, SF 266, SF 267, SF 268, SF 271, SF 292 and SF 629) were formulated and applied as a seed treatment and/or sprayed on the soil surface with the aim of controlling Pratylenchys brachyurus in common bean under field conditions. The application of the bacterial isolates neither improved the grain yield and the root mass nor reduced the number of nematodes in the soil and in the roots of common bean. Thus none of the isolates of Bacillus spp. evaluated in this work are promising for the control of the lesion nematode on common bean.