Monitoramento populacional de Dalbulus maidis com armadilhas amarelas adesivas em cultivos de milho de vários estados do Brasil
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Data
2023-11-28
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Universidade Federal de Viçosa
Resumo
A cigarrinha-do-milho (Dalbulus maidis) transmite os patógenos do complexo dos enfezamentos e na última década tem alcançado altas populações em certas regiões do Brasil. Contudo, suspeita-se que o inseto está amplamente distribuído em cultivos de milho de todo território nacional e que a densidade populacional varia com a região e características dos cultivos. O objetivo foi elaborar um panorama da ocorrência de D. maidis nos estágios vegetativos de cultivos de milho em localidades de diferentes estados do Brasil. A hipótese foi que a densidade populacional da cigarrinha nos cultivos de milho varia com a região do território nacional, com a janela de plantio de milho dentro da região e com os estágios de desenvolvimento da cultura. O estudo foi realizado na safra 2022/23 nas Regiões Sul, Sudeste, Centro- Oeste, Norte e Nordeste do Brasil. Armadilhas adesivas amarelas foram instaladas em cultivos de milho plantados na abertura (segunda quinzena de janeiro), meio (primeira quinzena de fevereiro) e fechamento da safra (segunda quinzena de fevereiro a início de março), a depender da região, pode ocorrer variações na janela de plantio. As regiões com plantios escalonados se alongam por mais períodos as janelas de semeaduras. As avaliações foram feitas em Zero dia (primeira avaliação, emergência das plantas), 30 dias (segunda avalição) e 60 dias (terceira avaliação) contagem das cigarrinhas. Os dados foram tabulados e com eles elaborou-se um mapa contendo alfinetes coloridos de acordo com número de cigarrinhas capturadas nas armadilhas. Na região Sul do Brasil, os cultivos de milho de três localidades (Cruz Alta-RS, Pato Branco-PR, Ponta Grossa-PR), e que foram plantados na abertura da safra, apresentaram armadilhas que capturaram mais de 40 cigarrinhas/armadilha/mês. Esses valores foram interpretados como indicativos de uma alta densidade populacional da cigarrinha nas plantas milho e o local onde eles ocorreram foi considerado de alto risco de transmissão de enfezamentos do milho. Aos 30-60 dias após o plantio (DAP), em uma dessas localidades, foram capturadas sete cigarrinhas (Cruz Alta-RS) e na outra somente uma (Pato Branco-PR), indicando queda da densidade populacional após 30 DAP. No Mato Grosso, as armadilhas instaladas em Sorriso em cultivo realizado na abertura da safra de milho capturaram 6, 1 e 16 cigarrinhas/armadilha/mês, respectivamente aos 0–30, 30–60 e 60–90 DAP. Nos cultivos do meio da safra, as armadilhas instaladas 30–60 DAP capturaram 13–32 cigarrinhas, captura que permaneceu nesse nível (22 cigarrinhas) em uma localidade monitorada (Campo Novo do Parecis). Nas Minas Gerais, Goiás, Oeste da Bahia, Tocantins e Maranhão, a maioria das armadilhas capturaram mais de 40 cigarrinhas/armadilha/mês, indicando altas populações da cigarrinha nessa região central do Brasil, seja em cultivos implantados na abertura, meio ou fechamento da safra no país. Em localidades onde se cultiva milho em uma ampla janela de plantio durante a safra, as armadilhas capturaram grande número de cigarrinhas (mais 110/armadilha/mês) na maioria dos cultivos e em diferentes estágios de crescimento da cultura. Esses resultados indicam que a população de D. maidis é bastante alta em algumas regiões do país e varia com a janela de plantio e com o estágio fenológico das plantas. Este estudo evidencia que o uso de armadilhas adesivas para monitoramento de D. maidis mostra variação na densidade populacional entre regiões, janelas de plantio de milho e seus estágios fenológicos. Mais estudos são necessários para determinar a correlação da população de adultos nas armadilhas com a densidade populacional do inseto nas plantas e a produtividade da cultura. Palavras-chave: cigarrinha do milho, densidade populacional, armadilha adesiva, janela de plantio, estágio fenológico.
The corn leafhopper (Dalbulus maidis) transmits the pathogens of the stunting complex and in the last decade has reached high populations in certain regions of Brazil. However, it is suspected that the insect is widely distributed in corn crops throughout the country and that the population density varies with the region and characteristics of the crops. The objective of this study was to develop an overview of the occurrence of D. maidis in the vegetative stages of maize crops in different states of Brazil. The hypothesis was that the population density of the leafhopper in corn crops varies with the region of the national territory, with the corn planting window within the region and with the maize growth stages. The study was conducted in the 2022/23 growing season in the South, Southeast, Midwest, North, and Northeast regions of Brazil. Yellow sticky traps were installed in corn crops planted at the opening (second half of January), middle (first half of February) and closing of the harvest (second half of February to beginning of March), depending on the region, variations in the planting window may occur. Regions with staggered plantings extend the sowing windows for longer periods. The evaluations were carried out at zero-day (first evaluation, plant emergence), 30 days (second evaluation) and 60 days (third evaluation) leafhopper count. The data were tabulated, and a map was elaborated containing colored pins according to the number of leafhoppers caught in the traps. In the southern region of Brazil, corn crops from three locations (Cruz Alta- RS, Pato Branco-PR, and Ponta Grossa-PR), which were planted at the opening of the growing season, presented traps that captured more than 40 leafhoppers/trap/month. These values were interpreted as indicative of a high population density of the corn leafhopper in maize plants, and the place where they occurred was at high risk of maize stunt transmission. At 30-60 days after planting (DAP), in one of these locations, seven leafhoppers were captured (Cruz Alta-RS) and in the other only one (Pato Branco-PR), indicating a decrease in population density after 30 DAP. In Mato Grosso, the traps installed in Sorriso in a crop cultivation carried out at the opening of the corn harvest captured 6, 1, and 16 leafhoppers/trap/month, respectively at 0–30, 30–60, and 60–90 DAP. In the mid-season crops, the traps installed 30–60 DAP captured 13–32 leafhoppers, a capture that remained at this level (22 leafhoppers) in a monitored locality (Campo Novo do Parecis). In Minas Gerais, Goiás, Western Bahia, Tocantins and Maranhão, most traps captured more than 40 leafhoppers/trap/month, indicating a high population density of the leafhopper in this central geographic region of Brazil. That occurred in maize crops planted at the opening, middle or end of the harvest in the country. In localities where corn is grown in a wide planting window during the harvest, the traps captured a large number of leafhoppers (more than 110/trap/month) in most crops and at different stages of crop growth. These results indicate that the population of D. maidis is quite high in some regions of the country and varies with the planting window and the plants growth stage. This study shows that the use of yellow sticky traps to monitor D. maidis shows variation in population density between geographical regions, maize planting windows, and their growth stages. Further studies are needed to determine the correlation of the adult population of corn leafhoppers in the traps with the insect population density in the plants and the productivity of the crop. Keywords: corn leafhopper, population density, sticky trap, planting window, growth stage.
The corn leafhopper (Dalbulus maidis) transmits the pathogens of the stunting complex and in the last decade has reached high populations in certain regions of Brazil. However, it is suspected that the insect is widely distributed in corn crops throughout the country and that the population density varies with the region and characteristics of the crops. The objective of this study was to develop an overview of the occurrence of D. maidis in the vegetative stages of maize crops in different states of Brazil. The hypothesis was that the population density of the leafhopper in corn crops varies with the region of the national territory, with the corn planting window within the region and with the maize growth stages. The study was conducted in the 2022/23 growing season in the South, Southeast, Midwest, North, and Northeast regions of Brazil. Yellow sticky traps were installed in corn crops planted at the opening (second half of January), middle (first half of February) and closing of the harvest (second half of February to beginning of March), depending on the region, variations in the planting window may occur. Regions with staggered plantings extend the sowing windows for longer periods. The evaluations were carried out at zero-day (first evaluation, plant emergence), 30 days (second evaluation) and 60 days (third evaluation) leafhopper count. The data were tabulated, and a map was elaborated containing colored pins according to the number of leafhoppers caught in the traps. In the southern region of Brazil, corn crops from three locations (Cruz Alta- RS, Pato Branco-PR, and Ponta Grossa-PR), which were planted at the opening of the growing season, presented traps that captured more than 40 leafhoppers/trap/month. These values were interpreted as indicative of a high population density of the corn leafhopper in maize plants, and the place where they occurred was at high risk of maize stunt transmission. At 30-60 days after planting (DAP), in one of these locations, seven leafhoppers were captured (Cruz Alta-RS) and in the other only one (Pato Branco-PR), indicating a decrease in population density after 30 DAP. In Mato Grosso, the traps installed in Sorriso in a crop cultivation carried out at the opening of the corn harvest captured 6, 1, and 16 leafhoppers/trap/month, respectively at 0–30, 30–60, and 60–90 DAP. In the mid-season crops, the traps installed 30–60 DAP captured 13–32 leafhoppers, a capture that remained at this level (22 leafhoppers) in a monitored locality (Campo Novo do Parecis). In Minas Gerais, Goiás, Western Bahia, Tocantins and Maranhão, most traps captured more than 40 leafhoppers/trap/month, indicating a high population density of the leafhopper in this central geographic region of Brazil. That occurred in maize crops planted at the opening, middle or end of the harvest in the country. In localities where corn is grown in a wide planting window during the harvest, the traps captured a large number of leafhoppers (more than 110/trap/month) in most crops and at different stages of crop growth. These results indicate that the population of D. maidis is quite high in some regions of the country and varies with the planting window and the plants growth stage. This study shows that the use of yellow sticky traps to monitor D. maidis shows variation in population density between geographical regions, maize planting windows, and their growth stages. Further studies are needed to determine the correlation of the adult population of corn leafhoppers in the traps with the insect population density in the plants and the productivity of the crop. Keywords: corn leafhopper, population density, sticky trap, planting window, growth stage.
Descrição
Palavras-chave
Cigarrinha-do-milho - Controle, Cigarrinha-do-milho - Populações, Armadilhas para insetos, Fenologia, Milho - Cultivo
Citação
DIAS, Analice Silva. Monitoramento populacional de Dalbulus maidis com armadilhas amarelas adesivas em cultivos de milho de vários estados do Brasil. 2023. 36 f. Dissertação (Mestrado em Ciência Florestal) - Universidade Federal de Viçosa, Viçosa. 2023.