At this moment a big inventarisation is in progress in order to find out where and how bears eat oilrich plants and crops. Data come from all over the world. Originially it was meant to discover if oilpalm rich areas suffer from the sunbears in India. But, as it becomes obvious from this footage from Alaska, where they grow corn, bears like to use this offer there as well. The footage shows what exactly the farmer is doing to prevent loosing crop and what the effects are of his investment.

crop loss due to grizzly bears (bear is in the bottom) in Alaska

This is an interesting topic. I don’t know of any bear problems with agricultural crops in Alaska, but there isn’t much going on up here.
I don’t think anyone posted a link to this video from People and Carnivores about grizzlies and corn in Montana, but I figured better redundancy than missing it.

Crop loss due to bears