Influência da aplicação de silício em milho (Zea mays) sobre o desenvolvimento de Spodoptera frugiperda (J. E. SMITH, 1797)

Abstract

Differential management of maize crop may lead to reduced attack of its main pest, the carpiaceous caterpillar, Spodoptera frugiperda. In this way, the effect of 4, 6 and 8 g doses of silicon in the soil was evaluated, applied in corn plants 36 days after planting in the development of the caterpillar. The experiments were conducted in a greenhouse and in the Laboratory of Entomology of the Federal University of Southern Frontier. Food preferences were evaluated in the free choice test; mortality and cannibalism in the test with no chance of choice and influence on the development of the pest, where the biological parameters evaluated were: mortality, larval and pupal period duration, pupal weight and sex ratio. In the first two bioassays, preference with chance of choice and mortality and cannibalism, there was no difference between the treatments and the control. As for the third bioassay, the dose of 8 g of silicon in the soil showed shorter duration of larval phase, however, pupa weight and sex ratio did not present difference. The highest percentage of mortality (45%) was also verified in the dose of 8g of silicon in the soil. Considering the results, it is possible to infer that the dose of 8 g of silicon in the soil decreases larval period.