Avaliação do plano de supressão populacional do bicudo-do-algodoeiro Anthonomus grandis, Boheman, 1843 (Coleoptera: curculionidae) no estado de Goiás

Abstract

The cotton crop has a economic social importance in Brazil and interacting with many economic sector from the country. The cotton plant hosted a pest complex that could damage to rot, stalk, leaf and reproductive structures. The boll weevil (Anthomnomus grandis, Boheman, 1843 (Coleoptera:Curculionidae) is considered the most important pest in the crop and has high damage potential. Because of the population reduction necessity of this Curculiondae from the region of Cotton crop Goiás State it was done the “Suppression Population Boll Weevil Plan”. The goal of this work was to test and make it sure the suppression methodology that was adopted at the pilot area. The work was realized in the Cedro Farm and Pamplona Farm located in Silvânia and Cristalina city respectively. It was realized descriptive analysis for the study: 1) attack percentage of the pest founded in the field pest scouting; 2) pest occurring during the harvest; 3) number of application to control the boll weevil; 4) population fluctuation of boll weevil capture in the pheromone trap during all hole year during in the harvest 2007/2008 and 2008/2009. The 2007/2008 harvest blocks were split in the crop inside area and “cerrado” area to compare the place where the most capture of boll weevil occurred. To compare the variation trap boll weevil per week (TBWW) it was used the non parametric U statistical test of Mann-Whitney to verify the difference between the two independent populations. It was considered the significance level α: 5% to analyze all the results period. It was considered eleven evaluating of agricultural year of 2004/2005, 2005/2006, 2006/2007 comparing with 2007/2008 (the first year of the program). In Pamplona Farm it was realized fourteen evaluated comparing 2006/2007 with 2007/2008 (trap of the total areas) growing season. The adopted measure to reduce boll weevil population it was efficient to reduce the capture of the insect in the trap before-harvest in the next year from the Suppression Program. Low levels of capture are related with delay of infestation and of damage caused by boll weevil in the next harvest. After the plant start growing the trap loses efficiency in the insect capture. The reduced populations founded in trap and in the scouting before-harvest take in a small number of the insecticides application. The strategy adopted by the “Suppression Population Boll Weevil Plan” were efficient to reduce pest population, and can be used to feasible harvest cotton sustainable model.