I'm not 100% sure I understand what you mean - will an industrial variety of hemp (which contains no THC) kill a THC containing variety if grown together? I cant understand why you would want to grow industrial hemp with non-industrial anyway, but the only issue I can see is with the gender of the plants.

Lets just grow it all and find out ...

If there are male plants with the female plants, they are considered hemp because the female plant doesn't produce bud and crystals, to attract the male (pollen) because it is already there. It has nothing to do with the hemp, it comes from hemp. The male plants destroy the drug. You have to pick out the males from the females as soon as you can tell (the male plants actually have little balls under the base leaves) and separate them. The THC comes from the female plants, it's their way of attracting the pollen.

When the plant is grown under conditions that are cold and humid, it produces fiber that is good for fabric (hemp) ... under hot and dry conditions, it produces oily resin ... it is the oily resin that contains the T.H.C., the drug.

Hemp is the stalk of the plant, usually not smoked by those who indulge.

Cannabis (Sativa L.) Is grown practically everywhere plants can grow. Climate has little or nothing whatever to do with the quality of Marijuana that can be produced from it. Marijuana is the flowering tops of the Cannabis plant. The difference between hemp and Marijuana is that hemp is grown in dense (Think bamboo patch)proximity to one another to encourage maximum yield of stalk and seed. Males and females grown together will mature the plant and produce seed (nuts) for food. Generally there is very little of the psychoactive property (Delta 9 Tetrahydrocannabinol) present in industrial hemp. Normal range is from 0.5 to 1.0 percent. Hemp can be and has been selectively bred for the purpose of creating higher percentages of THC, the result of these experiments is what is called Marijuana. They are the same thing, Cannabis is Cannabis, but just like cars, they aren't all created equal. If you remove the male hemp plant from within the stand of females before flowering, it will generally boost the THC production ever so slightly because rather than waste energy producing seed, it will produce more cannabinoids, one of which is THC. Year after year, gradually increasing as time goes on. It takes generations of selective breeding to accomplish good Marijuana from hemp, but that is how it was done. It is not true that you can make good Marijuana from hemp in one year, but in 10 years if you know what you are doing you may succeed. The best way to insure you are getting quality Marijuana is to use seed which has already been selectively bred for that purpose, otherwise you will be disapointed. GW Carver did some great research on hemp and marijuana at Tuskegee, his better known work is peanuts and soybeans.

HEMP is the male variety of cannabis; which contains near to no thc levels but grows very high and strong and is suitable for industial purposes. however the female plant is the marajuana variety which is smoke. now if a male plant where to be grown with a crop of females, the male plants would pollinate the females causing them to produce seeds which in term reduces thc levels in the female. this is how u get seeds. however this dramatically reduces thc levels and is why growing destroy the males plants. but it does not hewever "destroy" the female cannabis plant as it is still able to be used to smoke and get high