Avaliação de diferentes meios de proteção contra Tuta absoluta (Meyrick, 1917)
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2015
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Desde 2010, Tuta absoluta (Lepidoptera: Gelechiidae) tornou-se uma praga em Portugal caracterizada pelo seu elevado potencial biológico, especialmente nas solanáceas e com destaque para o tomate.
Originária da América do Sul, foi detetada em 2006 na Europa, em território espanhol e, facilmente, alastrou pelos restantes países mediterrânicos, chegando, em alguns casos, aos países do norte da Europa. Devido à horticultura intensiva presente na maioria dos países do Mediterrâneo, esta praga encontrou condições ideais para a sua instalação e permanência, relativamente aos hospedeiros e temperaturas necessárias ao seu desenvolvimento.
Apesar de atacar o tomateiro essencialmente na sua totalidade, este inseto destaca-se pelas larvas que provocam galerias nas folhas e nos frutos resultando assim numa diminuição da atividade fotossintética das folhas e a desvalorização comercial por parte dos frutos.
Como forma de atuação no controlo deste lepidoptero destacam-se as medidas indiretas como por exemplo a limpeza prévia da área de plantação de forma a eliminar a presença biológica deste inseto. Através de meios diretos apresentam-se os meios biológicos com fenómenos de predação por parte de antagonistas de ocorrência natural destacando-se a família miridae, os meios biotécnicos com armadilhas de captura em massa e meios químicos através do uso de inseticidas homologados que reduzem o número de indivíduos de T. absoluta.
O objetivo central deste trabalho foi analisar o comportamento de T. absoluta face a uma estratégia pré-definida de Motivos Campestres: o NEA de mais de 15 larvas vivas e sãs em 30 plantas casualizadas aleatoriamente por semana; 3 armadilhas de captura em massa distribuídas ao longo da área de estudo e os produtos Econatur, 2 bioinsecticidas baseados em extratos de plantas género Capsicum spp. e um inseticida com a bactéria entomopatogénica Bacillus thuringiensis.
Para verificar a eficácia deste plano foi comparada com uma estratégia usual da região sendo que o nível económico de ataque e os produtos aplicados ficaram ao critério do agricultor.
Os tomateiros foram divididos em 3 partes imaginariamente na vertical e registado a presença deste inseto e comparados para verificar qual o estrato com maior incidência. Tuta absoluta apresentou um comportamento frequente entre o estrato superior e o estrato médio nos tomateiros em todos agricultores ao longo do ensaio.
Os extratos de plantas do género Capsicum spp. não mostraram diferenças significativas em comparação aos produtos usuais no controlo da traça-do-tomateiro.
O segundo tema deste trabalho foi analisar quais os efeitos das formulações a que foram expostos determinados inimigos naturais.
A estratégia Motivos Campestres não apresentou diferenças significativas em relação à estratégia dos agricultores que lhes serviu de testemunhas apesar de apresentar maior presença de predadores e parasitóides nos períodos observados.
Sobre o ponto de vista económico os produtos Econatur usados pelos agricultores do plano foram mais caros mas a capacidade das embalagens perfaz mais tratamentos deste tipo do que as embalagens usadas pelas testemunhas.
Por fim foi realizado um inquérito aos agricultores Motivos Campestres com o intuito de analisar qual a satisfação destes perante os produtos testados.
Since 2010, Tuta absoluta (Lepidoptera: Gelechiidae) has become a plague in Portugal, characterized by its high biological potential, specially in Solanaceae and principally in tomatoes. Originally from South America, it was detected in 2006 in Europe, in Spain and easily spread to the other Mediterranean countries, reaching, in some cases, to the countries of northern Europe. Due to the intensive horticulture present in most Mediterranean countries, this pest found ideal conditions for its fixation and due to the hosts and temperatures required for their development. Although it attracks the tomato in its entirety, it stands out for its larvae that creates galleries in the leaves and fruits, resulting in a decrease of the photosynthetic activity of the leaves and devaluation of the commercial fruit. Some ways of action to control this Lepidoptera, are the indirect action/procedures such a as previous cleaning of the planting area in order to eliminate this insect. The direct action/procedures are the phenomena of predation by naturally biological media from existing antagonists with special attention of the Miridae family, the biotechnical technique with massive capture traps and chemical way by the use of approved insecticides that reduce the number of individuals of T. absoluta. The main objective of this study was to analyze the T. absoluta behavior in a Motivos Campestres pre-defined strategy’s: the economic level attack of 15 living and healthy larvae in 30 plants randomly picked per week; three massive capture traps distributed throughout the study area and with Econatur products, two bio-insecticides based on genus Capsicum spp. on plant extracts and an insecticide with the entomopathogenic bacterium Bacillus thuringiensis. To verify this plan effectiveness, it was compared with an usual strategy of the region, being and appliing the products, responsibility of the farmer as well as the inherent economic impact. Tomato plants were divided into 3 imaginary vertical parts and the presence of this insect in them was recorded and compared to see the stratum with higher incidence. Throughout the test, Tuta absoluta has presented a common behavior for both upper and middle layer in the tomato plants of all the farmers. Plant extracts of Capsicum spp. genus, showed no significant differences when compared with the usual control products for the tomate leafminer. The second theme was to analyze the formulation effects which have been exposed to determined natural enemies. Motivos Campestres pre-defined strategy’s showed no significant differences from farmers strategy and served them as a witness besides the higher amount of predators and parasitoids in the observed period. From an economically point of view, the Econatur products used in the farmers pre-defined strategy were more expensive but the capacity allows more treatments than the packages used by witnesses. A survey was conducted to Motivos Campestres farmers’s in order to analyze their satisfaction about the tested products.
Since 2010, Tuta absoluta (Lepidoptera: Gelechiidae) has become a plague in Portugal, characterized by its high biological potential, specially in Solanaceae and principally in tomatoes. Originally from South America, it was detected in 2006 in Europe, in Spain and easily spread to the other Mediterranean countries, reaching, in some cases, to the countries of northern Europe. Due to the intensive horticulture present in most Mediterranean countries, this pest found ideal conditions for its fixation and due to the hosts and temperatures required for their development. Although it attracks the tomato in its entirety, it stands out for its larvae that creates galleries in the leaves and fruits, resulting in a decrease of the photosynthetic activity of the leaves and devaluation of the commercial fruit. Some ways of action to control this Lepidoptera, are the indirect action/procedures such a as previous cleaning of the planting area in order to eliminate this insect. The direct action/procedures are the phenomena of predation by naturally biological media from existing antagonists with special attention of the Miridae family, the biotechnical technique with massive capture traps and chemical way by the use of approved insecticides that reduce the number of individuals of T. absoluta. The main objective of this study was to analyze the T. absoluta behavior in a Motivos Campestres pre-defined strategy’s: the economic level attack of 15 living and healthy larvae in 30 plants randomly picked per week; three massive capture traps distributed throughout the study area and with Econatur products, two bio-insecticides based on genus Capsicum spp. on plant extracts and an insecticide with the entomopathogenic bacterium Bacillus thuringiensis. To verify this plan effectiveness, it was compared with an usual strategy of the region, being and appliing the products, responsibility of the farmer as well as the inherent economic impact. Tomato plants were divided into 3 imaginary vertical parts and the presence of this insect in them was recorded and compared to see the stratum with higher incidence. Throughout the test, Tuta absoluta has presented a common behavior for both upper and middle layer in the tomato plants of all the farmers. Plant extracts of Capsicum spp. genus, showed no significant differences when compared with the usual control products for the tomate leafminer. The second theme was to analyze the formulation effects which have been exposed to determined natural enemies. Motivos Campestres pre-defined strategy’s showed no significant differences from farmers strategy and served them as a witness besides the higher amount of predators and parasitoids in the observed period. From an economically point of view, the Econatur products used in the farmers pre-defined strategy were more expensive but the capacity allows more treatments than the packages used by witnesses. A survey was conducted to Motivos Campestres farmers’s in order to analyze their satisfaction about the tested products.
Descrição
Dissertação de Mestrado em Engenharia Agronómica
Palavras-chave
Proteção das plantas , Luta integrada , Extratos de plantas , Traça-do-tomateiro