I'm Gwen Outen with the VOA Special English Agriculture Report.
The use of pesticides was an important part of the "Green Revolution," the movement that changed modern agriculture. Poisons can kill crop-eating insects, unwanted plants and harmful fungi. But these chemicals can also spread into the environment and kill helpful organisms.
Integrated pest management looks for a combination of methods to solve problems or prevent them.
Controlling pests starts with identification. Some kinds of insects, for example, look very similar. It is important to find out exactly what kind of pest is causing the damage and how much it has developed.
This first step can help farmers make other decisions. For example, no action may be needed if the problem is minor. Or, chemical treatments may not be needed if other methods can do the same job.
The University of California has had a Statewide Integrated Pest Management Program since nineteen seventy-nine. Experts have created guidelines that can help farmers create crop protection plans.
A good way to understand how these guidelines work is to look at a pest management program for a single crop. For example, alfalfa is an important food for farm animals, but also a target of many pests.
Alfalfa fields can support many biological controls. These are helpful insects and organisms that attack pests. If pesticides are needed, they must be chosen carefully. Use of the wrong poison will destroy helpful organisms and permit other pests to move in. Birds can also serve as important biological controls.
The way alfalfa is harvested can have a big effect, too. Harvesting parts of a field at different times can limit the spread of pests. Keeping a border of unharvested alfalfa by open water can also help.
Developed nations are the largest users of pesticides. But the Food and Agriculture Organization says the pesticide market in those countries is slowing or shrinking. The United Nations agency says several countries have set up programs to reduce pesticide use because of environmental concerns.
Today, many agriculture departments at universities teach integrated pest management methods.
Internet users can learn more about the Statewide Integrated Pest Management Program at the University of California at ipm.ucdavis.edu. Or you can find a link at www.unsv.com.
This VOA Special English Agriculture Report was written by Mario Ritter. I'm Gwen Outen.