MILHO DOCE BT COMO FERRAMENTA PARA O MANEJO DE LEPIDÓPTEROS PRAGA NO CENTRO-OESTE BRASILEIRO

Abstract

Sweet corn (Zea mays L. saccharata group) is known to have more sugar than conventional corn cultivars. The management of Lepidoptera in conventional maize has happened mainly by the application of insecticides and use of transgenic cultivars. However, in Brazil there is still very little information regarding the use of BT sweet corn to manage these pests. Thus, the present dissertation study proposed to evaluate the efficiency of BT sweet corn against lepidopteran pests. Two experiments were conducted at two different time periods. The experiments followed a randomized block design with four treatments and six replications in each experiment. The treatments are as follow: I - conventional plus insecticide; II - conventional without insecticide; III - BT plus insecticide; and IV - BT without insecticide. The treatments with insecticides were sprayed seven times following technical recommendations from the sweet corn industry personnel. The results showed a slower evolution of injury on the corn leaves (caused by caterpillars) in treatments with BT corn. Likewise, a significantly lower injury was observed in the ears (cobs and kernels) of BT plants, regardless of insecticide application. The number of caterpillars (S. frugiperda and Helicoverpa spp.) was also lower in the treatments with BT corn. In general, it was also observed larger ears and higher grain yield in treatments with BT corn. In summary, the study shows that BT sweet corn can be an important additional tool to be used in the integrated pest management programs of sweet corn pests, mainly targeting the control of S. frugiperda and Helicoverpa spp.