I’m Shep O'Neal with the VOA Special English Agriculture Report.

Sales of organic foods in the United States have been growing since the nineteen seventies.  The Organic Trade Association says sales last year reached almost fourteen thousand million dollars.  Yet that was only two and one-half percent of all food sales. 

But now there is a sign that organics have risen to a new level of economic importance.  This spring, Wal-Mart announced an effort to double the number of organic products in its stores. 

Stores like Whole Foods and Trader Joe’s have sold organic products for years.  But in recent years organic sales have grown sharply.  Products like organic milk and eggs have appeared in most grocery stores. 

Wal-Mart sells thousands of products, including food.  Many of its stores contain markets.  Wal-Mart says it wants to offer greater choice to more people. 

But critics say the actions of such a huge seller could put pressure on organic producers.  They say it will be harder to know if producers are following the rules for organics as larger companies push demand higher. 

At the same time, Wal-Mart's efforts are expected to push prices lower.  A Wal-Mart official reportedly said his company plans to sell organics at only ten percent over the price of non-organic versions. 

Some people have been willing to pay five or ten times that.  They believe organic foods are healthier and safer.  Others dispute this, and some say it can depend on the products.

Organic products may not be genetically engineered.  They must be made only with natural processes and materials.  Crops must be raised without most of the chemicals that farmers use now.  Animals cannot be given antibiotics or other drugs to increase growth.  And they must be fed organically grown food.

Yet the food industry uses many different marketing terms.  Claims like "all-natural" can mean different things.  But a product must contain at least ninety-five percent organic materials to be called organic. 

Some people worry that the rules for organic foods will be weakened as big companies expand into the market.

The National Organic Program of the United States Department of Agriculture sets those rules.  Farms must give a production plan to a certifying agent approved by the department.  If the agent approves the plan, only then can the U.S.D.A. Organic Seal appear on their products.