Much as I hate to agree with CG, you would probably get a bigger response if you posted this in Over the Fence or New Gardeners.
Having said that, the Iroquois planted the "three sisters" (corn, beans and squash) as companion plants--plant the corn first, then when the corn is knee high or so, plant the beans (fixes nitrogen in the soil while giving the bean vine something to climb on) then when the beans have sprouted and started climbing the cornstalks plant the squash (shades the soil causing it to need less moisture, and using the same basic footprint of the beans and corn). This is just one example of companion planting. Companion planting can also be for attracting pollinators, giving pests a feeding plant that attracts them more than the crop, and I'm sure I've missed some. I don't know of any other specific companions for corn except that a lot of people plant Sunflowers with their corn--not sure the benefits, but it sure looks pretty.
If you don't have wrinkles around your eyes, you haven't smiled enough.
Actually there was a recent post or article in either OG mag, OG online or Mother Earth that showed that volume/weight production of an individual crop variety actually fell in relation to single variety planting, but the total production of all three (they used the three sisters) was more than any single crop planting. Companion planting can be used for other benefits besides actual production of single crop--but I'm not sure corn has any companion specific to increasing yield.
If you don't have wrinkles around your eyes, you haven't smiled enough.
