Which is more necessary for success - talent or interest?
One needs talent or skills to be able to execute a task. Personally, i think talent is an inborn skill - it cannot be groomed. However, I think skills can be drilled and gained through experience.
Even with the required talent/skills, success may still not be achieved if there is no interest. Interest provides motivation to perfect/achieve a goal. And this interest is a must the more challenging the goal is.
Put simply, I think talent/skills are the technical requirements for success, whereas interest is the 'soft' requirements for success. It's hard to say that one is more necessary than the other, don't you think?