Acaricidas utilizados na citricultura convencional e orgânica: manejo da leprose e populações de ácaros fitoseídeos
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Data
2010-12-01
Autores
Andrade, Daniel Júnior de [UNESP]
Oliveira, Carlos Amadeu Leite de [UNESP]
Pattaro, Fernando César [UNESP]
Siqueira, Diego Silva [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Fruticultura
Resumo
O controle da leprose dos citros no Estado de São Paulo é realizado quase que exclusivamente com aplicações de acaricidas para o controle do ácaro vetor Brevipalpus phoenicis, as quais contribuem para o aumento dos custos de produção e podem afetar negativamente as populações de organismos benéficos. Portanto, o objetivo do trabalho foi avaliar, durante quatro safras, os efeitos de acaricidas indicados para o controle do ácaro B. phoenicis em citros convencional e orgânico sobre a evolução da leprose dos citros e sobre ácaros fitoseídeos. O experimento foi instalado em outubro de 2003, em pomar de laranja localizado no município de Reginópolis-SP. O delineamento experimental foi em blocos casualizados, estabelecendo-se os tratamentos, expressos em mL de p.c./100 L de água: spirodiclofen a 20 mL e cyhexatin a 50 mL (aplicados em rotação), calda sulfocálcica a 4.000 mL e testemunha sem aplicação de acaricidas. Entretanto, a rotação entre spirodiclofen e cyhexatin iniciou-se em setembro de 2006 e, anteriormente a esse período, utilizou-se somente o spirodiclofen. A cada quinze dias, foram realizados levantamentos populacionais do ácaro B. phoenicis e dos ácaros predadores Iphiseiodes zuluagai e os do gênero Euseius. O nível de controle adotado para o B. phoenicis foi de 8,3%, sendo que as aplicações dos produtos foram realizadas com pulverizador de arrasto tratorizado munido com lanças manuais. Na safra de 2007-2008, coletaram-se 10 frutos caídos devido à leprose por parcela e quantificou-se o número de lesões de leprose presentes em cada fruto. Avaliaram-se, ao término da safra de 2007-2008, a produtividade, as perdas devido à leprose, bem como a incidência e a severidade da leprose. Constatou-se que o local das lesões no fruto é mais importante para determinar sua queda do que o número de lesões presentes. Quanto mais intensa a infestação do ácaro B. phoenicis, maior é o número de lesões de leprose, resultando em maior queda prematura de frutos. Os acaricidas spirodiclofen e cyhexatin e spirodiclofen em rotação proporcionaram controle mais eficiente de B. phoenicis, em relação à calda sulfocálcica, resultando em maior produtividade, menores perdas de frutos e nos menores níveis de severidade da leprose. As aplicações de calda sulfocálcica reduziram os níveis populacionais do ácaro B. phoenicis abaixo do nível de controle, porém não evitaram o surgimento de lesões de leprose. As aplicações dos acaricidas apresentaram efeito nocivo sobre os ácaros fitoseídeos, pois houve redução da densidade populacional.
The citrus leprosis control in São Paulo state is performed exclusively by acaricides to control the vector mite, Brevipalpus phoenicis, which increases the production costs and may affect the beneficial organism's population. Therefore, the aim of this trial was to evaluate during four seasons, the effects of acaricides recommended to control the mite B. phoenicis in conventional and organic citrus over evolution of citrus leprosis and over phytoseiids' population. The experiment was installed in October of 2003 in a citrus orchard in Reginópolis city, state of São Paulo. The experimental design used randomized blocks, the dosages was expressed as mL c.p./ 100 L of water and the treatments were the following: spirodiclofen (20 mL); cyhexatin (50 mL) (used in rotation), lime sulfur (4,000 mL) and control (without pesticide application). However, the rotation between spirodiclofen and cyhexatin began in September 2006. Prior to that time, only spirodiclofen had been used. Surveys were conducted every 15 days on the B. phoenicis, Iphiseioides zuluagai,and Euseius populations. The control level adopted by the B. phoenicis was 8.3%, and the pesticide applications were conducted using tractor-sprayers. During the 2007-08 seasons, 10 infected fallen fruits per plot were collected and the number of leprosis lesions was quantified by each fruit. By the end of the 2007-08 seasons, the productivity, harvest losses, the disease incidence and severity were evaluated. It was found that the lesions' location over the fruit is more important in determining its drop than the lesions' number. The more intense the mite infestation, the greater is the number of lesions, resulting in increased premature fruit drop. A strategy using acaricides spirodiclofen and cyhexatin in rotation promoted more efficient control of B. phoenicis compared to lime sulfur, resulting in greater productivity, lower fruit losses and severity levels. The lime sulfur applications reduced the mite population incidence below the control level; however it did not prevent the lesions' occurrence. The acaricides applications prevented adverse effects on phytoseiid population because there was a reduction of their density.
The citrus leprosis control in São Paulo state is performed exclusively by acaricides to control the vector mite, Brevipalpus phoenicis, which increases the production costs and may affect the beneficial organism's population. Therefore, the aim of this trial was to evaluate during four seasons, the effects of acaricides recommended to control the mite B. phoenicis in conventional and organic citrus over evolution of citrus leprosis and over phytoseiids' population. The experiment was installed in October of 2003 in a citrus orchard in Reginópolis city, state of São Paulo. The experimental design used randomized blocks, the dosages was expressed as mL c.p./ 100 L of water and the treatments were the following: spirodiclofen (20 mL); cyhexatin (50 mL) (used in rotation), lime sulfur (4,000 mL) and control (without pesticide application). However, the rotation between spirodiclofen and cyhexatin began in September 2006. Prior to that time, only spirodiclofen had been used. Surveys were conducted every 15 days on the B. phoenicis, Iphiseioides zuluagai,and Euseius populations. The control level adopted by the B. phoenicis was 8.3%, and the pesticide applications were conducted using tractor-sprayers. During the 2007-08 seasons, 10 infected fallen fruits per plot were collected and the number of leprosis lesions was quantified by each fruit. By the end of the 2007-08 seasons, the productivity, harvest losses, the disease incidence and severity were evaluated. It was found that the lesions' location over the fruit is more important in determining its drop than the lesions' number. The more intense the mite infestation, the greater is the number of lesions, resulting in increased premature fruit drop. A strategy using acaricides spirodiclofen and cyhexatin in rotation promoted more efficient control of B. phoenicis compared to lime sulfur, resulting in greater productivity, lower fruit losses and severity levels. The lime sulfur applications reduced the mite population incidence below the control level; however it did not prevent the lesions' occurrence. The acaricides applications prevented adverse effects on phytoseiid population because there was a reduction of their density.
Descrição
Palavras-chave
Brevipalpus phoenicis, Vírus da leprose dos citros - CiLV, Citrus sinensis e Seletividade, Brevipalpus phoenicis, Citrus Leprosis Virus - CiLV, Citrus sinensis, Selectivity
Como citar
Revista Brasileira de Fruticultura. Sociedade Brasileira de Fruticultura, v. 32, n. 4, p. 1028-1037, 2010.