Tratamentos para combate as diferentes geracoes da traca da uva Lobesia botrana Schiff.

PORTUGUES: Neste trabalho apresenta-se uma sintese da experimentacao ligada ao controlo da Lobesia botrana, realizada pela Divisao de Controlo de Pragas e Doencas (CNPPA), de 1984 a 1987, no Ribatejo e Oeste. Essa experimentacao tinha os seguintes objectivos: - estudar a eficacia de insecticidas no combate a 1. e a 2. geracoes de traca; - determinar a oportunidade do tratamento para combater a 1. geracao; - verificar a influencia de tratamentos no combate as duas primeiras geracoes; - estudar a influencia dos tratamentos contra a 2. e/ou 3. geracao. Os insecticidas ensaiados apresentaram resultados satisfatorios. A oportunidade de intervencao contra a 1. geracao influenciou os resultados obtidos relativamente ao grau de ataque, apresentando o tratamento durante o periodo de eclosao dos ovos os melhores resultados; porem a producao nao foi afectada. O tratamento contra a 1. geracao mostrou-se mais eficaz em relacao ao tratamento contra a 2. geracao. Nao se registaram diferencas significativas no grau de ataque entre os tratamentos feitos contra a 2. geracao e/ou 3. geracao e a producao tambem nao foi afectada. O flucitrinato aplicado contra a 2. geracao nao apresentou resultados satisfatorios.

English. Results obtained during the 1984-1988 period on experimental work carried out on the control of Lobesia botrana (insect which has three generations/year) are summarized in this paper. In vineyards of Ribatejo (Valley of River Tagus) and Oeste, trials were set up to study: (I) the efficacy of insecticides used to control the 1st or the 2nd insect generation, (II) the timing of treatments to control the 1st generation, (III) the influence of treatments on the control of the first two generations, and (IV) the influence of treatments on the control of the 2nd and 3rd generation. All the insecticides tested showed good efficacy but flucytrinate (2nd generation). Timing of treatments against the 1st generation showed some influence on the degree of efficacy of treatments but grape yield was not affected. The treatment against the 1st generation showed a very good effect when the control of the first two generations was considered. As far as the control of the 2nd and 3rd generation is concerned no differences were showed when treatments were carried with untreated controls.