Smear on agarose gel from QIAGEN extracted plant samples - (Aug/29/2012 )

Would anyone know if it is common to observe these types of smears on an agarose gel after extracting DNA using a QIAGEN DNeasy 96 kit and running 500 ng of DNA in a 1% gel at 70 volts for 3 hours inside a 4 Celsius fridge (also tried at room temperature)?

I'm planning on sending these samples for Genotyping-by-Sequencing but the requirements for such procedure include no smearing on agarose gel neither discrete low molecular weight bands.... which I think I have. Any imput will be appreciated

I am not a plant biologist but we usually get this type of smear when we don't add RNAse in the last step of our extraction.