Here's some background on the whys and hows of roguing:
When seed corn is planted, some of the seeds, a very low percentage, are undesired. The undesired corn plants are called rogue corn. Roguers are the folks who chop or dig out the undesired corn.
What's the problem with rogue corn? If the rogue corn is allowed to mature, it will contaminate (pollinate) the hybrid corn. Roguers are told how to spot the unhelpful corn and eliminate it.
Detasseling is the process of removing the top part of a corn plant, the tassel, so that the plant cannot pollinate itself. The task of pollination is done by another type of corn grown for that sole purpose. The result is a superior breed of corn that has genetic characteristics of both the pollinating and detasseled corn plants.
Removing tassels from corn plants is actually the simplest part of a very complex business involving the genetics of seed corn. By the time detasselers step in the fields, seed corn producers have already invested a great deal of time and money to develop the best seed. Detasseling is one of the crucial last steps in bringing a hybrid seed to market.
Despite attempts at mechanization, the helping hand of the detasseler is still needed to produce a pure and superior seed. When left to grow naturally, a corn plant will pollinate itself. To produce a better type of corn, different strains of corn are mixed, or cross-pollinated. Seed corn fields are planted with two types of corn: one type is detasseled and will bear the new hybrid seed corn, the other type will only serve to pollinate. Normally fields are planted with a ratio of three to four "female" rows of corn for every "male" row. (A corn plant normally is both male and female, capable of fertilizing itself; the designations of male and female only describe the role that certain corn plants have been given for the sake of creating a hybrid seed corn.)
To produce the hybrid seed, tassels are removed from the female plants before they can pollinate themselves. Timing is important. Detassel too early and you risk decreasing the yield. Wait too long and the corn plant will have started to pollinate itself, ruining the seed. Seed companies take meticulous care of their fields, closely watching them in order to predict when they'll need to bring in detasselers. Still, it's a tough call, and everyone is at the mercy of the weather.
When the time is right, detasselers have to work quickly. The season can start anytime from late June to late July, depending on growing conditions. Days off are rare, but the entire season lasts only about three weeks. Detasselers beat the summer heat by starting at sunrise and working until mid-afternoon. Detasselers must remove 99.5% of all female tassels in order to complete a field. This usually means making two or three passes through each field to make sure it's "clean."