Manejos de borda em pomares de citros na epidemiologia do Huanglongbing
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Data
2018-11-05
Autores
Montesino, Luiz Henrique
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Huanglongbing (HLB), doença associada às bactérias Candidatus Liberibacter asiaticus e Candidatus Liberibacter americanus, está presente em todas as regiões do parque citrícola paulista, causando grandes prejuízos à produção e a qualidade dos frutos. Sua transmissão ocorre pelo psilídeo Diaphorina citri que, frequentemente, migra de um pomar para outro em busca de novas brotações para se alimentar e reproduzir. A faixa de borda na divisa da propriedade é a região de maior concentração do inseto após sua chegada ao pomar, vindo de áreas vizinhas, onde o seu controle não é realizado. Apesar de um controle mais intensivo do inseto nesta região da propriedade, com aplicações frequentes de inseticidas, um maior número de plantas com HLB tem sido mais encontrado e erradicado na faixa de borda que no interior do pomar. Para evitar que a doença penetre cada vez mais para o meio da propriedade e haja um manejo economicamente sustentável da doença, neste trabalho analisou-se o gradiente do HLB em talhões com linhas de plantios paralelo e perpendicular e a incidência média por faixas de 20 a 160 m, os dados apresentaram melhor resultado no sentido paralelo entre os sentidos de plantio e a incidência média foi menor em todas as faixas para o sentido de plantio paralelo com redução média de 25% na incidência e a prática da manutenção de plantas doentes na faixa de borda, associada a um controle intensivo do vetor. Foram selecionados cinco talhões na divisa da propriedade, com citros nas propriedades vizinhas, divididos em quatro parcelas de 150 a 200 m sendo duas localizadas na borda do talhão ao lado da divisa da propriedade (B1 e B2) e duas no centro do talhão. Em todas as parcelas foram realizadas inspeções mensais para a detecção de sintomas de HLB, monitoramento de psilídeos, com 20 cartões adesivos amarelos distribuídos pelo talhão. Quanto ao número de psilídeos capturados, o talhão 4 foi o que teve maior captura (média de 0,0104 psilídeos/cartão/avaliação). Não foram observadas diferenças significativas para a média de psilídeos capturados por cartão por avaliação na comparação entre parcelas. Dos psilídeos capturados, mais de 50% encontravam-se infectados com C. L. asiaticus, indicando uma alta taxa de infectividade na região. A estratégia de manter uma faixa de borda sem a erradicação de plantas doentes, associada a um frequente controle do psilídeo é uma alternativa que não aumenta a taxa de progresso do HLB na propriedade e poderia proporcionar ganhos de produção, custeando as aplicações frequentes de inseticidas nesta faixa de borda.
Huanglongbing (HLB), a disease associated with the bacteria Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus, is present in all regions of the São Paulo citrus park, causing great damage to fruit production and quality. Its transmission occurs by the psilid Diaphorina citri, which often migrates from one orchard to another in search of new shoots to feed and reproduce. The border strip in the property boundary is the region of highest concentration of the insect after its arrival in the orchard, coming from neighboring areas, where its control is not realized. Despite a more intensive control of the insect in this region of the property, with frequent applications of insecticides, a greater number of plants with HLB has been more found and eradicated in the edge band than in the orchard. To avoid that the disease penetrates more and more to the middle of the property and there is an economically sustainable management of the disease, in this work the HLB gradient was analyzed in fields with parallel and perpendicular planting lines and the average incidence by bands of 20 a 160 m, the data presented a better result in the parallel sense between the planting senses and the mean incidence was lower in all the bands for the parallel planting direction, with an average reduction of 25% in incidence and the practice of maintaining diseased plants in the range associated with an intensive vector control. Five plots were selected in the property boundary, with citrus in neighboring properties, divided into four plots of 150-200 m, two located on the edge of the plot next to the property boundary (B1 and B2) and two in the center of the plot. In all plots monthly inspections were carried out for the detection of HLB symptoms, monitoring of psyllids, with 20 yellow adhesive cards distributed throughout the plot. As for the number of captured psilids, plot 4 had the highest capture (mean of 0.0104 psilids / card / evaluation). No significant differences were observed for the average number of captured per - carded per - psyllids in the comparison between plots. Of the captured psilids, more than 50% were infected with C. L. asiaticus, indicating a high infectivity rate in the region. The strategy of maintaining a borderline without the eradication of diseased plants associated with frequent psilid control is an alternative that does not increase the rate of progress of HLB on the property and could provide production gains by funding the frequent applications of insecticides in this border strip.
Huanglongbing (HLB), a disease associated with the bacteria Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus, is present in all regions of the São Paulo citrus park, causing great damage to fruit production and quality. Its transmission occurs by the psilid Diaphorina citri, which often migrates from one orchard to another in search of new shoots to feed and reproduce. The border strip in the property boundary is the region of highest concentration of the insect after its arrival in the orchard, coming from neighboring areas, where its control is not realized. Despite a more intensive control of the insect in this region of the property, with frequent applications of insecticides, a greater number of plants with HLB has been more found and eradicated in the edge band than in the orchard. To avoid that the disease penetrates more and more to the middle of the property and there is an economically sustainable management of the disease, in this work the HLB gradient was analyzed in fields with parallel and perpendicular planting lines and the average incidence by bands of 20 a 160 m, the data presented a better result in the parallel sense between the planting senses and the mean incidence was lower in all the bands for the parallel planting direction, with an average reduction of 25% in incidence and the practice of maintaining diseased plants in the range associated with an intensive vector control. Five plots were selected in the property boundary, with citrus in neighboring properties, divided into four plots of 150-200 m, two located on the edge of the plot next to the property boundary (B1 and B2) and two in the center of the plot. In all plots monthly inspections were carried out for the detection of HLB symptoms, monitoring of psyllids, with 20 yellow adhesive cards distributed throughout the plot. As for the number of captured psilids, plot 4 had the highest capture (mean of 0.0104 psilids / card / evaluation). No significant differences were observed for the average number of captured per - carded per - psyllids in the comparison between plots. Of the captured psilids, more than 50% were infected with C. L. asiaticus, indicating a high infectivity rate in the region. The strategy of maintaining a borderline without the eradication of diseased plants associated with frequent psilid control is an alternative that does not increase the rate of progress of HLB on the property and could provide production gains by funding the frequent applications of insecticides in this border strip.
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Palavras-chave
Controle, Plantio (Cultivo plantas), Laranjeira doce, Frutas cítricas doenças e pragas, Control, Planting (Plant culture), Sweet orange tree, Citrus fruits Diseases and pests DLC