That’s why governments around the world have accepted GM crops.

As the evidence for the advantages of GM crops mounts, skeptics are turning into converts. Last month at the Oxford Farming Conference in Britain, former Greenpeace activist Mark Lynas apologized for his earlier opposition to biotechnology and urged governments and farmers to adopt 21st-century practices for the sake of the environment.

So by banning a couple of previously approved GM crops, Poland is moving in exactly the wrong direction. Our government has turned back the clock on food production.

Worst of all, our public officials know that GM crops are safe for human consumption. If they truly believed otherwise, they would forbid the purchase of GM food from other countries. Yet each year we import more than 2 million tons of GM soybeans for food and feed, as well as corn, cotton, and other crops.

The message is irrational and incomprehensible. It says that GM crops are acceptable for everyone, including Polish consumers–but that Polish farmers under no circumstances may use a proven technology that has led to a boom in production everywhere it has been tried.

Poland must continue to push forward into a bright future of hope and opportunity, not backward into a new Dark Age that views innovation and technology with terror. It must not leave its farmers behind.

Roman Warzecha grows maize, sweet corn, rape and cherries on a family farm in the Mazowia region of Poland.  Mr. Warzecha leads maize and triticale research at Poland’s Institute of Plant Breeding and Acclimatization (IHAR) and is a member of the TATT Global Farmer Network (