Manejo de Dalbulus maidis (DELONG & WOLCOTT) (Hemiptera Cicadellidae) com inseticidas e efeito da adubação silicatada na indução de resistência de plantas de milho

Abstract

Maize (Zea mays L.) is one of the most important crops in Brazil. It is among the cereals grown in the country and in the world. Maize presents two harvests in Brazil and, with this, simultaneous planting and harvesting is observed in different Brazilian regions. The adoption of integrated pest management (IPM) has been shown to be a viable alternative, encompassing a series of control measures to avoid economic damage caused by pests. Maize diseases, known as hay bumps, have caused enormous damage to maize crops, especially in warmer regions of Brazil, which is precisely where maize is grown in more than one crop year. The corn leafhopper Dalbulus maidis is a species responsible for significant losses in production, both because it is a sucking insect and because it is the transmissible species of molicutes, phytoplasma and spiroplasma, causal agents of corn stunting, and the Maize rayado fino marafivirus. The objective of the present study was to evaluate the efficiency of insecticides in corn seed treatment, and later, in foliar application and the interaction of the effect with silica fertilization, both via soil and leaf, on the control of D. maidis. The present study was conducted at the Capim Branco Experimental Farm, Federal University of Uberlândia, Brazil. It consisted of 10 treatments to evaluate the efficiency of seed treatment and 10 treatments to evaluate the efficiency of foliar application. Spraying was done using a costal spray, equipped with an flat fan spray nozzle, with a spray volume of 200 L / ha. The evaluations were made by visual counting of adult individuals present in each of the evaluated plants. Significant differences were observed for seed treatment, and the Gaucho® insecticide was the best evaluated. Plant height did not differ for any of the treatments, and no induction of resistance was observed by silicon application. In the foliar application, efficiencies were observed in the control of D. maidis, with the Connect® insecticide obtaining an efficiency of 76% up to 7 DAA. However, no effects of silicon foliar application were observed.