Currently the tags for seeds are c:seeds/(plant)_seeds, going with the way other tags are made they should be c:seeds/(plant). This would mean the following would tags would be changed:

Rice Seeds: c:seeds/rice_seeds - c:seeds/rice
Cucumber Seeds: c:seeds/cucumber_seeds - c:seeds/cucumber
Soy Seeds: c:seeds/soy_seeds - c:seeds/soy
Wasabi Seeds: c:seeds/wasabi_seeds - c:seeds/wasabi