This is less of a botany forum than it is a gardener's forum.
Yes, you can cross pepper plants. Cucurbits are even easier. Corn will cross easily too. It takes dedication, and usually isolation, and rigorous documentation if you really want someone else to care about your results. I know there are books in your school library that will give you the fundamentals, and maybe outline some experiments you could do.
https://www.ubcbotanicalgarden.org/forums/index.php is the website of the University of British Columbia's Botanical Gardens forum. It's the most technical of fora that I've seen. I'm sure there are some lists and BBS that are more specific to botanical research. Through UBC's fora, I've learned of citrus, palm, aroid, and gesneriad societies where people do actually cross breed and report.
There, as here, you are less likely to get a response to a nebulous question. From how you name yourself to what you ask there is a disparity. A botanist wannabe would probably already know the basics, so people here might be reluctant to spell out what they know. OTOH, other botanists here and elsewhere would be reluctant to detail higher level applied science. Honestly, I've "met" people who do gene splicing of plants.
I've deduced that you are between 10 and 15 years of age, and not in an expensive academy. You might be a fast track student without a lot of academic guidance.
If you get no other replies here, try a more specific question as in, "Crossing peppers? Anyone?"
If you go to UBC, identify yourself as a student learning on your own. Expect to be directed to other sites rather than have someone walk you through it. UBC is not as conversational as this forum. It's just a different strokes kinda thing.
Last edited by thanrose
on Thu Jul 08, 2010 2:48 pm, edited 2 times in total.