Uso de agentes microbianos e químico para o controle de Meloidogyne incognita em soja

Abstract

RESUMO.Nematoides de galhas constituem importante grupo de patógenos da cultura da soja e o manejo integrado é uma das principais medidas de controle que visam à redução de perdas econômicas. Neste trabalho foi avaliada a eficácia dos fungos Paecilomyces lilacinus (Thom.) Samsom e Pochonia chlamydosporia (Goddard) Zare & Gams (sinonímia Verticillium chlamydosporium), de um produto comercial à base de Bacillus sp. (Nemix) e do nematicida químico Aldicarb no controle de Meloidogyne incognita em soja, variedade M-SOY 6101. O experimento foi realizado em casa-de-vegetação no delineamento experimental de blocos casualizados com nove tratamentos (três produtos biológicos usados no tratamento de sementes com ou sem a aplicação em pós-emergência, Aldicarb aplicado apenas em pós-emergência e duas testemunhas) e quatro repetições. Aldicarb reduziu o número de ovos e de juvenis do nematoide. P. lilacinus foi o mais atuante dos agentes biológicos, favorecendo a manutenção da quantidade de matéria seca da raiz de soja e reduzindo o número de ovos. O produto Nemix e P. chlamydosporia somente tiveram ação efetiva na redução do número de ovos do nematoide. Com base nos resultados, foi possível concluir que o agente químico e os agentes biológicos avaliados neste trabalho tiveram moderada atividade no controle de M. incognita em soja. ABSTRACT. Use of microbial and chemical agents to control Meloidogyne incognita in soybean.Root-knot nematodes are considered significant pathogens of soybean crops. The objective of this work was to evaluate the efficacy of two fungi (Paecilomyces lilacinus (Thom.) Samsom and Pochonia chlamydosporia (Goddard) Zare & Gams (syn. Verticillium chlamydosporium), a commercial product based on Bacillus sp. and Aldicarb on the control of Meloidogyne incognita on soybean, cultivar M-SOY 6101. The experimental design was set as randomized blocks with four replications. Nine treatments were evaluated: three biological agents used for seed treatment with and without post-emergence application, Aldicarb on post-emergence only, and two controls. All treatments were inoculated with the nematode, except for a blank control where only water was applied. One control-only treated with the nematode was also included. Aldicarb could reduce the number of eggs and juveniles in the roots. P. lilacinus showed the best performance among the biological control agents, reducing the number of eggs and increasing dry root weight. Nemix, a Bacillus sp. based commercial product and P. chlamydosporia could only reduce significantly the number of eggs of the nematode. In this work, it was possible to conclude that the chemical and biological agents showed a moderate activity in the control of M. incognita in soybean.

Daily Indexes for Predation and Growth of Nematophagous Mushrooms Species of Hohenbuehelia (Pleurotaceae) on Panagrellus redividus

“…Therefore, this genus performs two important functions to ecosystem: wood decomposition and pests control (Mankau, 1980). Further, saprophytic ability turns biological agents into a promising control strategy (Nunes et al, 2010) and nematode trapping fungi present no specificity to host so any nematode in soil can be preyed by them (Askary, 2015). Koziak et al (2007) confirm that Nematoctonus genus are found in agricultural soils and contains predators and parasitoids species, unlike other nematophagous genus that generally contemplates only one control profile.…”

Biological control of Meloidogyne javanica in bean plants by Hohenbuehelia spp. and Trichoderma koningiopsis

“…Likewise, AL-HAZMI; TARIQJAVEED (2016) checked different performances among species, justified by pathogenic ability of the isolates or their origin. By analyzing the reduction percentual of galls and egg masses of M. javanica (Tables 3 and 4), it was verified that H. mastrucata, H. portegna and H. petaloides presented control potential superior to many commercial products of antagonists, such as Rizotec in cucumber (VIGGIANO et al, 2014), Rizotec and Onix SC + Quality WG in tomato (CARVALHO, 2017), Nemix TS in soybean (NUNES et al, 2010), Trichodermil SC 1306and Quality in bean (AGUIAR et al, 2014, revealing the potential for commercial use, especially remembering that these results were obtained with low dosage of inocula.…”

“…Researches on biocontrol of nematodes generally consider the introduction of the antagonist agent before transplanting the plant host (DALLEMOLE-GIARETTA et al, 2008;AL-HAZMI;TARIQJAVEED, 2016), resulting in a longer interaction to reduce nematode inoculum. It is an advantage for ovicidal antagonists, such as Trichoderma (SZABÓ et al, 2012) and Pochonia chlamydosporia (NUNES et al, 2010). In this study, fungi were added during sowing, having 19 days to establish in the substrate and roots before the addition of M. javanica.…”

“…On the other hand, no matter what crop or biocontrol agent it is, there is a strong relation between egg masses number and galls expression (LOPES et al, 2007;PUTZKE et al, 2007;SANTIN, 2008;DALLEMOLE-GIARETTA et al, 2008;NUNES et al, 2010;MACHADO et al, 2013;PINHEIRO et al, 2013).…”

Controle biológico de fitonematoides via semente no cultivo da soja

“…Geralmente, são classificados segundo seu hábito nutricional. Dentre os grandes grupos de nematoides estão os fitonematoides, ou nematoides parasitas de plantas, que causam perdas econômicas significativas em uma grande variedade de culturas (Nunes et al, 2010).…”