Advertisement
Book Review/Science in the Media

Redefining “Natural” in Agriculture

  • Tony Trewavas
  • Published: August 19, 2008
  • DOI: 10.1371/journal.pbio.0060199

Reader Comments (2)

Post a new comment on this article

Redefining “Natural” in Agriculture

Posted by plosbiology on 07 May 2009 at 22:26 GMT

Author: Pam Ronald
Position: No occupation was given
Institution: No affiliation was given
E-mail: pcronald@ucdavis.edu
Submitted Date: August 21, 2008
Published Date: August 22, 2008
This comment was originally posted as a “Reader Response” on the publication date indicated above. All Reader Responses are now available as comments.

I appreciate the review of our book by Tony Trewavas. Here I would like to comment on his point that "plants have always used chemicals to control pests".

Because plants are rich in sugars, proteins, vitamins and minerals, they make obvious and tempting treats for various predators. Plants cannot run away, so instead they have evolved a set of defenses to protect themselves. Celery is seemingly benign, yet it produces toxic compounds called psoralens to discourage predators and avoid being a snack too early in its life cycle. Sometimes humans are the accidental victims of psoralen poisoning.

Breeders have selected celery with relatively high amounts of psoralens because farmers prefer to grow insect resistant plants and consumers prefer to buy undamaged produce. Unfortunately, workers who harvest such celery sometimes develop a severe skin rash (NAS 2004), an unintended consequence of this conventional breeding.

Raoul, who is an organic farmer discovered that green potatoes make pretty good rodent poison. One day he went into the certified organic hoophouse to find three dead mice near some freshly eaten green potatoes. Potatoes produce glycoalkaloid solanine, a toxic compound, although most varieties have amounts so small that they are considered nonhazardous to animals. Some potato varieties, however, have higher levels than others and certain conditions such as light can cause hazardous levels of the toxin to be produced.

So far, compounds that are toxic to animals have only cropped up in foods developed through conventional breeding approaches. There have not been any adverse health or environmental effects resulting from commercialized GE crops. This may be because foods produced by GE undergo additional scrutiny, or it may be that there simply are not yet many GE crops on the market. Whatever the reason, this important fact is sometimes lost in the debates on GE food.

Many people view genetic engineering of crops as “unnatural” and see it as an inappropriate tool to use in crop breeding.

What sort of criteria, then, can we use to assess its benefits?

An appropriate technology, as asserted by the economist Schumacher in his book Small is Beautiful, should promote values such as health, beauty, and permanence (Schumacher 1973). Low cost and low maintenance requirements are also of prime importance in Schumacher’s definition. Considering both Schumacher’s observations and our goals for ecological farming, it is apparent that GE will sometimes be appropriate for food modification and sometimes not. This is because GE is simply a tool that can be applied to a multitude of uses, depending on the decisions of policy makers, farmers, and consumers.

Still, as we attempt to show in our book, GE comprises many of the properties advocated by Schumacher. It is a relatively simple technology that scientists in most countries, including many developing countries, have perfected. The product of GE technology, a seed, requires no extra maintenance or additional farming skills. Its arrangement of genes can be passed down from generation to generation and improved along the way. It is therefore clear that humans will likely reap many significant and life-saving benefits from GE. This is because even incremental increases in the nutritional content, disease resistance, yield, or stress tolerance of crops can go a long way to enhancing the health and well-being of farmers and their families. There is also potential for applications of GE to reduce the adverse environmental effects of farming and enable farmers to produce and sell more food locally. Indeed, the use of GE has already drastically reduced the amount of pesticides sprayed worldwide, saved the U.S. papaya industry, and provided new tools to save the lives of impoverished children.

Competing interests declared: I am co-author of the book