A lot of corn keepers use the Munson plan. But you do need a postal/kitchen scale in order to actually follow it.

http://medusa-corns.webs.com/feedingchart.htm

I personally feed on a modified munson plan. My corn is growing fine on one 3-4g pink a week. I need to re-weigh her and see where I should be at according to the plan, but I feed once a week. It works very well for my schedule.