Genótipos resistentes, controle biológico e defensivos seletivos para o manejo integrado de Tetranychus evansi (Acari: Tetranychidae) em tomateiro
Carregando...
Data
2022-03-04
Autores
Savi, Patrice Jacob [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O ácaro vermelho do tomateiro, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), é uma praga invasora do tomateiro em vários países, com potencial de reduzir a produtividade em até 90% na África. Devido ao alto potencial biótico da praga, o manejo focado no uso de defensivos sintéticos muitas vezes não é eficiente ou insustentável ao longo do tempo, sendo necessária a sua integração com outros métodos de controle. Estudos anteriores encontraram em genótipos selvagens fonte expressiva de resistência (tricomas glandulares) que poderiam ser exploradas para aumentar o nível de resistência de variedades de interesse a esta praga. Além disso, Phytoseiulus longipes Evans (Phytoseiidae), encontrado na América do Sul, mostrou-se um promissor ácaro predador de T. evansi. No entanto, a integração deste ácaro predador em programas de MIP onde T. evansi é um problema sério requer conhecimento detalhado das interações com outras práticas de manejo. Dessa forma, objetivou-se com este trabalho estabelecer um sistema de manejo integrado para T. evansi com a aquisição de genótipos de tomateiro resistentes, biopesticides eficientes a T. evansi, um genótipo adequado que pudesse otimizar o desempenho do ácaro predador Phytoseiulus longipes Evans (Phytoseiidae) e com a definição de agrotóxicos comumente usado em tomateiro seletivos a esse predador. Os estudos foram conduzidos em condições de laboratório e semi-campo. As progênies F1, SPJ-10-2017 e SPJ-05-2018 obtidas cruzando o genótipo selvagem resistente [Solanum habrochaites, acesso PI 134417] com Solanum lycopersicum, cv TLCV15 [importante genótipo cultivado amplamente cultivado no Benin] herdaram significativos tricomas glandulares tipos I, IV e VI de seu pai resistente (PI 134417). As densidades de tricomas glandulares herdados pelos genótipos da progênie foram capazes de reduzir ou suprimir as infestações causadas por T. evansi. No entanto, o genótipo de progênie causou atrasos importantes no crescimento populacional e reduziu significativamente a sobrevivência e o potencial de predação de P. longipes. Os genótipos cultivados com maior número de tricomas não glandulares mostraram-se adequados para a implementação do programa IPM que visa otimizar o uso de P. longipes como agente de biocontrole. Os resultados demonstraram que o uso de biopesticidas à base de azadirachtin e oxymatrine apresentaram alta atividade contra T. evansi e pode ser uma importante alternativa para uso no manejo de T. evansi em substituição ou rotação com acaricidas sintéticos. Além disso azadiractina mostrou-se também mais segura ao ácaro predador tanto no controle biológico aumentativo quanto na conservação, enquanto a oximatrina mostrou-se adequada apenas para o controle biológico aumentativo se 10 dias for observado após aplicação. Os agrotóxicos comumente usados no sistema de cultivo do tomateiro como abamectina, propargite, imidacloprid e o fungo entomopatogênico Hirsutella thompsonii (Fischer) (Deuteromycetes) são mais compatíveis com o controle biológico aumentativo do que com a conservação se os prazos de segurança adequados forem respeitados antes da liberação. Os inseticidas piretróides (cipermetrina e deltametrina) e organofosforados (dimetoato, clorpirifós) não são compatíveis com o uso de P. longipes em programas de MIP. Esses resultados são importantes para o manejo sustentável dessa praga invasora e, ao mesmo tempo, fornecem diretrizes práticas que possibilitam uma melhor forma de uso de agrotóxicos em programas de MIP que visam conservar ou realizar liberações aumentativas do ácaro predador.
The tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), is an invasive tomato pest in several countries, with the potential to reduce yield by up to 90% in Africa. Due to the high biotic potential of the pest, the management focused on the use of synthetic pesticides is often not efficient or unsustainable over time, requiring the integration with other control methods. Previous studies found in wild genotypes expressive source of resistance (glandular trichomes) that could be explored to increase resistance level of varieties of interest to this pest. Furthermore, Phytoseiulus longipes Evans (Phytoseiidae), found in South America proved to be a promising predatory mite of T. evansi. However, the incorporation of this predatory mite into IPM programs requires detailed knowledge of the interactions with other management practices. Within this context, the objective of the present study was to establish an integrated management system with the acquisition of tomato genotypes resistant to T. evansi, a suitable genotype that could optimize the performance of predatory mite P. longipes and with the definition of selective pesticides to this predator.The studies were conducted under laboratory and semi-field conditions. Our results indicated that the progenies F1, SPJ-10-2017 and SPJ-05-2018 obtained by crossing the wild-resistant genotype [Solanum habrochaites, Knapp e Spooner var glabratum access PI 134417] with Solanum lycopersicum L., cv. TLCV15 [cultivated genotype widely grown in Benin] have inherited significant glandular trichomes types I, IV and VI from their resistant parent (PI 134417). The densities of these glandular trichomes inherited by progeny genotypes were able to reduce supress the infestation caused by T. evansi. However, the bred progeny genotype SPJ-05-2018 caused important delays population growth and reduced significantly a survival, and the predation potential of P. longipes. The cultivated genotypes with many non-glandular trichomes proved to be more suitable for the implementation of IPM program that aim to optimize the use of P. longipes as biocontrol agent. The results showed that the use of azadirachtin- and oxymatrine based biopesticides had high activity against T. evansi and may be an important alternative in the management of the mite in replacement or rotation with synthetic acaricides. Azadirachtin proved to be the safest against the predatory mite toward both augmentative biological control and conservation whereas oxymatrine proved to be suitable only toward augmentative biological control 10 days after application. Other pesticides used in tomato cropping system such as abamectin, propargite, imidacloprid and the enthomopathogenic fungus Hirsutella thompsonii (Fischer) (Deuteromycetes) are more compatible with augmentative biological control than conservation if appropriate safety deadlines are respected before release. The insecticides belonging to pyrethroid (cypermethrin and deltamethrin) and organophosphate (dimethoate, chlorpyrifos) groups are not compatible with the use of P. longipes in IPM programs. These results are important to sustainably manage this invasive mite pest, and at the same time, provide practical guidelines to enable a better way of using pesticides in IPM programs that aim to conserve or increase the predatory mite P. longipes.
The tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), is an invasive tomato pest in several countries, with the potential to reduce yield by up to 90% in Africa. Due to the high biotic potential of the pest, the management focused on the use of synthetic pesticides is often not efficient or unsustainable over time, requiring the integration with other control methods. Previous studies found in wild genotypes expressive source of resistance (glandular trichomes) that could be explored to increase resistance level of varieties of interest to this pest. Furthermore, Phytoseiulus longipes Evans (Phytoseiidae), found in South America proved to be a promising predatory mite of T. evansi. However, the incorporation of this predatory mite into IPM programs requires detailed knowledge of the interactions with other management practices. Within this context, the objective of the present study was to establish an integrated management system with the acquisition of tomato genotypes resistant to T. evansi, a suitable genotype that could optimize the performance of predatory mite P. longipes and with the definition of selective pesticides to this predator.The studies were conducted under laboratory and semi-field conditions. Our results indicated that the progenies F1, SPJ-10-2017 and SPJ-05-2018 obtained by crossing the wild-resistant genotype [Solanum habrochaites, Knapp e Spooner var glabratum access PI 134417] with Solanum lycopersicum L., cv. TLCV15 [cultivated genotype widely grown in Benin] have inherited significant glandular trichomes types I, IV and VI from their resistant parent (PI 134417). The densities of these glandular trichomes inherited by progeny genotypes were able to reduce supress the infestation caused by T. evansi. However, the bred progeny genotype SPJ-05-2018 caused important delays population growth and reduced significantly a survival, and the predation potential of P. longipes. The cultivated genotypes with many non-glandular trichomes proved to be more suitable for the implementation of IPM program that aim to optimize the use of P. longipes as biocontrol agent. The results showed that the use of azadirachtin- and oxymatrine based biopesticides had high activity against T. evansi and may be an important alternative in the management of the mite in replacement or rotation with synthetic acaricides. Azadirachtin proved to be the safest against the predatory mite toward both augmentative biological control and conservation whereas oxymatrine proved to be suitable only toward augmentative biological control 10 days after application. Other pesticides used in tomato cropping system such as abamectin, propargite, imidacloprid and the enthomopathogenic fungus Hirsutella thompsonii (Fischer) (Deuteromycetes) are more compatible with augmentative biological control than conservation if appropriate safety deadlines are respected before release. The insecticides belonging to pyrethroid (cypermethrin and deltamethrin) and organophosphate (dimethoate, chlorpyrifos) groups are not compatible with the use of P. longipes in IPM programs. These results are important to sustainably manage this invasive mite pest, and at the same time, provide practical guidelines to enable a better way of using pesticides in IPM programs that aim to conserve or increase the predatory mite P. longipes.
Descrição
Palavras-chave
Insetos, Tomate, Genotoxicidade, Pesticidas