03193naa a2200169 a 450000100080000000500110000800800410001910000280006024501300008826000090021830000160022749000370024350001800028052022980046070000190275877302460277714668062007-07-27       2004    bl uuuu     u00u1 u    #d1 aCORRÊA-FERREIRA, B. S.  aSusceptibility of soybean to the attack of the stink bugs Euschistus heros and Piezodorus guildinii prior to pod development.  c2004  ap. 219-220.  a(Embrapa Soja. Documentos, 228).  aEditado por Flávio Moscardi, Clara Beatriz Hoffmann-Campo, Odilon Ferreira Saraiva, Paulo Roberto Galerani, Francisco Carlos Krzyzanowski, Mercedes Concordia Carrão-Panizzi.  aThe occurrence of high populations of the soybean stink bugs (Euschistus heros and Piezodorus guildinii) prior to pod set, has been a matter of constant concern and questioning by soybean farmers and technical assistance. To evaluate the damages caused by these stink bug population, present in the soybean fields, during the months of November/December, greenhouse and field experiments were carried out using infested soybean plants at vegetative-flowering growth stages. The damage caused by this early population was compared to those occurring during the critical period for stink bugs attack, the pod development stage. Soybean plants at vegetative and flowering growth stages, even under severe bugs infestation (8/plant) showed no significant on yield reductions. Seed quality, evaluated by the tetrazolium test, was also similar among population levels and between bug species. When the infestation with the brown stink bug occurred at vegetative (V6), and flowering (R1) stages, the yield was similar to those observed in the bug-free plants (control). Differently, at the stage R4, the productivity was lower than the control when the infestation was two to four bugs/plant. Only at the stage R4, the number of seedless pods at the upper half of the plant increased as the number of bugs/plant increased, varying from 1.7 in the control treatment to 9.1 for plants with four bugs. In a 15 days-infestation field experiment, yield and seed quality of soybean plants infested with up to four E. heros or P. guildinii adults per meter, at the end of the vegetative-flowering stage, were not affected when compared to bug-free plants. Otherwise, average yield decreased with the increase of population levels of both bug species, when infestations occurred at the pod filling stage (R5-R6). Data from seed quality analysis showed an increase in the number of bug-punctured and unviable seeds. This damage increased proportionally with the increase in the level of infestation tested although the damage caused by P. guildinii was twice the damage caused by the brown stink bug. These results confirm literature data and indicate that control measures applied on early development soybean stages, prior to pod set, are not justifiable for these species and the population levels studied.1 aAZEVEDO, J. de  tIn: WORLD SOYBEAN RESEARCH CONFERENCE, 7.; INTERNATIONAL SOYBEAN PROCESSING AND UTILIZATION CONFERENCE, 4.; CONGRESSO BRASILEIRO DE SOJA, 3., 2004, Foz do Iguassu. Abstracts of contributed papers and posters. Londrina: Embrapa Soybean, 2004.