I have a PhD in agronomy. I now want to get more hands-on experience in plant breeding. Most post doctoral positions I see require applicants to have graduated no more than 2 years before applying.
I don't fit into this category as I have graduated long after the past 2 years. Do I apply for another PhD or a masters instead, to enable me to enhance my research skills in this area?
Preferable would be a postdoc in a close to relevant area that overlaps with your new and old interests, more so with the former.
While earning a second PhD or MSc can have benefits, they will usually not outweigh that of a PostDoc. It is not uncommon to change your field slightly when doing a postdoc.
Perhaps a research job in a company in the industry can give you the experience you seek? I would suggest getting in touch with a career counsellor to discover your other options as well.
Somewhat typically for this SE, the answer is "Just do it". Don't know how approach your advisor? Just do it. Don't know how to write a proposal? Just do it. Don't know how to do more research in X? Just do it. Formalities are important to observe for a career, but they are still secondary to the substance of your work.
You have a certain skillset, and a desire to do things outside of it, as is common in academia. Landing a job is a mutual thing: there is something of value to the employer (your skills), and something of value to you (getting paid and learning). Your background seems to overlap sufficiently with the desired target, so there seems no reason to get more formal education full-time. Find a group that does what you want and at least a bit of what you can do (or feasibly has a need in that) and apply there. Education-wise... one might end up getting certifications along their career path, but getting stuck in school perpetually is just no good.
