If I understand your question properly, you have corn planted in a block with several rows but only those stalks on the ends of the rows have ear development. Do you mean that there are no ears at all, or that the ears have few kernals that mature?
If the former, the most probable cause would be stress at a critical time early in the plant's development, usually insufficient water. It could also be some other environmental stressor. If the situation is that the cobs aren't filling out, that is usually a result of insufficient pollination. Corn is air pollinated by the pollen moving from the tassels to the silk on the developing ears which usually requires a sufficiently large planting of corn for good pollination.
In larger fields, wind takes care of corn pollination. Between air circulation and stalks jostling one another in the wind, there is enough natural agitation to spread the pollen. In smaller garden plots, the gardener that's sometimes insufficient and you can hand pollinate instead.
To pollinate corn efficiently, wait until the tassels are fully open and beginning to shed the yellow pollen. This usually begins 2-3 days before silk emerges from the embryonic ears. As soon as the silk emerges, you’re ready to begin the manual pollination of corn. Pollination will continue for another week under ideal conditions. Most pollen shedding occurs between 9:00 and 11:00 am, after the morning dew has dried. Cool, cloudy, or rainy weather can delay or inhibit pollination.
Timing is everything. Once you have the when, how to hand pollinate corn is a snap. Literally! Snap the tassels off a few stalks and use them like feather dusters. Dust over the emerging silks at each ear. You’ll be hand pollinating corn for about a week, so use your judgment as to how many tassels you snap per dusting. Start at the opposite ends of your rows each night to help equalize the distribution. That’s it! You’ve successfully completed your manual pollination of corn.Good luck and don't hesitate to call your extension office at 541-776-7371 if you more questions.
Thank you very much... I did have some watering problems early with hoses splitting and corn was not watered properly for about a week. That was probably my problem. Also in the middle of my rows there is not any silk so as I understand there would be no good in hand pollinating unless I see silk.