Associação de inseticidas biológico e químico reduz a intensidade e o dano causado pelos enfezamentos na cultura do milho

Abstract

The corn leafhopper (Dalbulus maidis) has emerged as one of the most important pests in maize cultivation in Brazil, due to its high efficiency in transmitting the pathogens responsible for red and pale stunt diseases, which can cause severe yield losses. Although chemical control is widely adopted, it presents limitations regarding sustainability and the risk of selecting resistant pest populations. In this context, the combined use of chemical and biological strategies appears as a viable and effective alternative for pest management. This study aimed to evaluate the association between biological and chemical insecticides in the control of D. maidis, and their effects on disease incidence and maize yield. The field experiment was conducted in Santa Helena Parana (PR), using the hybrid P3282VYH, in a randomized block design with four treatments: control (no insecticide), application of a biological insecticide (Isaria fumosorosea), a chemical insecticide (methomyl), and the combination of both. Evaluations included the incidence and severity of stunt diseases, as well as final grain yield. The results showed that the combined application significantly reduced disease incidence and provided the highest productivity levels, with a yield increase of over 1,000 kg ha⁻¹ compared to the untreated control. It is concluded that the integration of chemical and biological control represents an effective and sustainable strategy for managing corn stunt complex and D. maidis, contributing to greater yield stability and reduced reliance on chemical products alone