MARSEF at Missouri Western on March 9 is for grades 9-12. Homeschoolers are most definitely welcome to participate if they live in our region. Anyone living in Platte county should apply to the Kansas City fair. There is also the Junior High MARSEF on March 12. That is run by the St. Joseph school district. Information can be found here: http://www.sjsd.k12.mo.us/Page/11475
Yes, we can extend the deadline. If you fill out the SRC forms found on our website(http://www.missouriwestern.edu/orgs/marsef/), we can process them ASAP. There might be some cases that we will not be able to accept, if they required Scientific Review Committee (SRC) approval before experimentation began, but did not receive it. However, if someone qualified checked out the project before it started, they can act as SRC. (I know there are a lot of rules, but we have to follow the rules of ISEF to send out students there.)
We would be very excited to see what your students have been doing! If you have any more questions, please don't hesitate to contact me.
Dr. Jonathan Rhoad
Department of Chemistry
College of Liberal Arts and Sciences
Missouri Western State University