Manejo do complexo de pragas do algodoeiro em refúgio estruturado

Abstract

The fields of Structured Refuge Treated in crop systems with cotton Bt may require complex pest control; for such refuge is important develop management models with selectivity criteria. This study aimed to evaluate two Management Systems of the complex of pests in cotton nonBt. The study was conducted in a cotton growing area (FM 951LL), characterized as refuge area in the town of Chapada dos Guimarães, MT, in Summer (2013/2014). The Management Systems were arranged in groups with twelve repetitions totaling 5.76 ha per treatment, characterized as: (T1) Selective Management Insecticides, adopting use of biological control tools to Heliothinae subfamily (Helicoverpa armigera, Helicoverpa zea e Heliothis virescens), and selective chemical pesticides until Anthonomus grandis of detecting, respecting pre-defined level of control; (T2) Conventional System Insecticides, consisting of insecticide synthetic chemical treatments and management decision taking into account the pre-defined level of control, in additional the farm's operational capacity accomplish control operation. Both treatments recorded the presence of Aphis gossypii, Bemisia tabaci, Spodoptera eridania, Heliothineos, Polyphagotarsonemus latus, Tetranychus urticae and Anthonomus grandis above the level control fact the needed to control, but the cost T1 was really higher, on the other hand, T2 was characterized by extensive use of chemical synthetic broad-spectrum, as well as the highest volume used, factor responsible for the lower occurrence percentage of natural enemies, but these factors did not differ in productivity and quality of cotton fiber. The selective management the pest complex in cotton with a focus on preservation of the environment is possible, but requires more technical knowledge and high cost though without financial performance superior to conventional management.