Efeito de óleo essencial de laranja associados a fungicidas no controle de doenças foliares do trigo

portugais. RESUMO Foi conduzido um experimento em campo na safra de 2012 com o objetivo de avaliar a contribuição do óleo essencial de laranja na performance dos fungicidas visando o controle de doenças foliares do trigo. O delineamento experimental foi o de blocos ao acaso em arranjo fatorial (3x5) + 1, com quatro repetições. O fator A foi composto pelos fungicidas (dose do produto comercial) epoxiconazol (0,75L ha-1), piraclostrobina (0,80L ha-1) e epoxiconazol+piraclostrobina (0,75L ha-1) e o fator B pelos adjuvantes (doses) óleo mineral (500mL ha-1) e óleo essencial de laranja (0, 50, 100 e 150mL ha-1). O tratamento adicional compreendeu-se pela testemunha (água). O controle de manchas foliares na folha bandeira foi mais eficaz com a aplicação de epoxiconazol e de epoxiconazol+piraclostrobina independentemente do adjuvante usado ser óleo mineral ou óleo essencial de laranja, enquanto que os adjuvantes testados não interferiram no controle da ferrugem. O peso do hectolitro, massa de mil grãos e a produtividade do trigo não foram afetados negativamente pelas diferentes concentrações do óleo essencial de laranja.

anglais. ABSTRACT A field experiment was conducted during the 2012 growing season with the aim of evaluating the contribution of orange essential oil to the performance of fungicides on the control of wheat leaf diseases. The experimental design was in randomized blocks, as factorial arrangement (3x5) + 1, and four replicates. Factor A was composed of the fungicides (dose of the commercial product) epoxiconazole (0.75L ha-1), pyraclostrobin (0.80L ha-1) and epoxiconazole+pyraclostrobin (0.75L ha-1) and factor B was composed of the adjuvants (doses) mineral oil (500mL ha-1) and orange essential oil (0, 50, 100 and 150mL ha-1). The additional treatment was represented by a control (distilled water). Flag leaf spot control was more efficient with the use of epoxiconazole and epoxiconazole+pyraclostrobin whether the used adjuvant was mineral oil or orange essential oil, while the tested adjuvants did not affect rust control. The hectoliter weight, mass of one thousand grains and wheat yield were not negatively affected by the different concentrations of orange essential oil.