Pesquisa Agropecuária Brasileira (Mar 2000)
Controle da lagarta-da-soja com aplicações de seu vírus de poliedrose nuclear por vias aérea e terrestre Control of the velvetbean caterpillar through air and land applications of its nuclear polyhedrosis virus
Abstract
De 1983 a 1988 foram conduzidos, na região de Dourados, MS, seis experimentos e três campos-piloto, objetivando controlar a lagarta Anticarsia gemmatalis Hübner, 1818, com aplicações aérea e terrestre de seu vírus de poliedrose nuclear (VPN Ag). Cem lagartas equivalentes (LE) de VPN Ag associadas a óleo de soja, melaço de cana-de-açúcar e água, foram aplicadas com avião agrícola equipado com Micronair. Os preparados oleosos (5,5 e 5 L ha-1) e com melaço (10 L ha-1) controlaram 75-89% e 79-96% das lagartas, respectivamente. A suspensão aquosa de 3 L ha-1 foi ineficaz, porém as de 15, 20 e 25 L ha-1 controlaram de 81% a 90% das lagartas. Cinqüenta LE, aplicadas com avião agrícola (3 L ha-1) ou atomizador (15 L ha-1), foram ineficientes. Aplicações da mesma dose com pulverizador de barra (134 e 150 L ha-1) proporcionaram controle de 87% e 90%, respectivamente, e com avião (15, 20 e 25 L ha-1), entre 93% e 98%. Aplicações aéreas de 50 LE com óleo de soja (5 L ha-1) ou melaço (10 L ha-1) foram eficientes (86-88% e 99%, respectivamente). Aplicações aéreas de suspensões aquosas e formulado oleoso, em campos-piloto, confirmaram os resultados experimentais.From 1983 to 1988 six experiments and three pilot fields were carried out at Dourados, Mato Grosso do Sul State, Brazil, aimed at controlling Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) larvae through air and land applications of its nuclear polyhedrosis virus (Ag NPV). One hundred larval equivalents (LE) of NPV were applied, with soybean oil, sugar cane molasses and water, with an Ipanema spraying plane equipped with Micronair nozzles. The oil (5.5 and 5 L ha-1) and molasses (10 L ha-1) preparations yielded 75-89% and 79-96% control, respectively. The use of aqueous formulation (3 L ha-1) didn't provide good control, but 15, 20 and 25 L ha-1 were effective (81-90%). Fifty LE applied by plane at 3 L ha-1 or by a tractor propelled atomizer (15 L ha-1) was inefficient. Fifty LE applied with a bar sprayer (134 and 150 L ha-1) provided 87-90% control. When applied by plane (15, 20 and 25 L ha-1) the control was 93-98%. Air applications of 50 LE using soybean oil (5 L ha-1) and sugar cane molasses (10 L ha-1) were efficient, providing 86-88% and 99% control, respectively. The results obtained from the pilot fields were similar to the ones obtained with the experiments.
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