[IT IS HARVEST WEEK AT GREENSEEDLING!  This week, we’ll be featuring a timely collection of stories comparing organic and conventional food.   HAPPY THANKSGIVING to our U.S. readership!] A major difference between organic and non-organic crops involves the use of pesticides to ward off weeds or insects that may damage the crops. However, with the advent of “natural” pesticides, organic farmers do have options to protect their crops. For example, farmers could use oils derived from tobacco to rid their plants of insects, or they could not use any pesticide at all and simply reap the same benefits that their nearby neighbor with Bacillus thurgiensis toxin (Bt) crops gets.

Although there have been many positive effects associated with the use of natural pesticides and Bt crops, there are also drawbacks. Production of organic insecticides can often be costly or inefficient, while Bt crops face an entirely different problem. In a recent study done by researchers at the University of Notre Dame, remnants of Bt crops have been shown to flow downstream and into areas where Bt crops are not normally found.

When these insecticidal byproducts of Bt crops infiltrate other ecosystems, they could cause multiple problems. First of all, the insects in these areas can be directly impacted by the transgenic remains. As a result of directly lowering the fitness of non-resistant insects, insects resistant to Bt crops could become more prevalent. As mentioned in the second referenced article above, Bt crops planted in one field can also help minimize the damage done to non-Bt crops in adjacent fields because insects cannot differentiate between Bt and non-Bt fields. With the migration of Bt remnants downstream into other ecosystems, the delicate balance of non-Bt and Bt crops could be thrown off, resulting in the evolution of Bt-resistance in insects.
With this in mind, do Bt crops really provide a significant advantage over traditional and natural pesticides? In fact, could transgenic Bt crops actually accelerate the evolution of Bt-resistance in insects more quickly than spraying Bt toxin on crops? Further research will be key to answering these important questions, but we must also focus our attention on preventing the migration of transgenic remnants into other areas.

Discussion Question: What is one possible method for minimizing the migration of transgenic parts of crops to other ecosystems?

News Article: http://www.sciencedaily.com/releases/2010/09/100928111128.htm
Journal Article: http://www.pnas.org/content/107/41/17645