The thematic session on Crop Biotic Stresses on Friday 7 October, 2011 touched upon various research into crop production and crop management methods. While the results were also unique, the discussions at Tropentag focused their interest on the improvement of methodologies. The impacts of crop management. The session looked at the effects of Chlorpyrifos in Costa Rica and how they are having a negative impact on the children in the area. The exposure came from the use of Chlorpyrifos-bags used in banana and plantain Plantations. We were also introduced to the research through a microarray analysis of gene expression induced in tomato leaves. The genes were compared between treated/untreated/diseased/healthy tomato plants and observed for activation of plant resistance. Interestingly enough, someone in the crowd commented on the research and arrived at opposite results having done the same research. The debate was left up in the air… to be continued during the following coffee break. Fellow presenters listening to their colleague's presentation. Africa stricken with Striga!