March 03, 2015 22:35 UTC

Science & Technology

Getting a Firm Grip on Weed Control

Read, listen and learn English with this story. Double-click on any word to find the definition in the Merriam-Webster Learner's Dictionary.

Chiyoko Kaizuka weeds her spinach field in Moriya, Ibaraki prefecture, Japan
Chiyoko Kaizuka weeds her spinach field in Moriya, Ibaraki prefecture, Japan

Multimedia

Play or download an MP3 of this story
This is the VOA Special English Agriculture Report.
 
When is a plant considered a weed? Experts at Penn State University have a simple answer: When the undesirable qualities outweigh the good qualities.
 
Consider the fact that crops generally produce several hundred seeds from each plant. By comparison, each weed plant can produce tens or even hundreds of thousands of seeds. And some buried seeds can survive up to forty years -- or even longer.
 
Eradicating weeds means that you have to remove all the seeds and roots so the plants will not grow back. But birds or the wind can reintroduce them to the land.
 
A more common way to deal with weeds is to control them enough so that the land can be used for planting. Experts advise using two or more control methods to deal with weeds. 
 
Chemical weed killers or natural treatments like corn gluten can suppress weed growth. Dense planting of a crop can also act as a natural control.
 
Bill Curran is a professor of weed science at Penn State, in University Park, Pennsylvania. He says one of the most common methods for suppressing weeds is dense planting.
 
He says a dense, competitive crop that quickly shades the soil will help suppress many weeds. The seeds need light to grow, so blocking the sun will reduce weed growth.
 
Other controls include turning over the soil, pulling the weeds or covering them with mulch made of shredded wood, garden waste or other material.
 
But even mulch has its limits. Natural resource specialists point out that weeds can be transported in mulch. This is also true of soil, grain, hay and animals.
 
Yet animals like sheep or goats eat weeds, so they can provide a biological control. Insects and other organisms can also act as biological controls.
 
Preventing the spread of weeds is an important part of weed management. Farm vehicles should be kept out of areas with weeds. If that is not possible, then clean off the equipment and your shoes when leaving.
 
Some people burn weeds or bury them deeply or make them into mulch.
 
Professor Curran says another way to make use of weeds is to compost them. Heat is produced in the process of making organically rich compost to improve soil. The heat will kill many, though not all, weed seeds. The same is true for seeds that pass through animals that graze on weeds.
This forum has been closed.
Comment Sorting
Comments
     
by: Rocío from: Spain
01/27/2013 3:24 PM
My father has a ground with grass and weeds. He is thinking about to boy a coat. After reading this, I am going to encourage him to do it!!

Thanks a lot for your work, it helps me to improve my English.

Learn with The News

  • Audio Top Ten Cities With the World's Worst Traffic

    "I love sitting in traffic!" said nobody ... ever. We all hate traffic. If you want to complain about traffic in English, this article will help. And you can find out if your city made the Top Ten List for Worst Traffic. Also, find out which cities have the fastest moving traffic on the planet. More

  • Jakarta MRT

    Audio What Can Help Jakarta's Huge Traffic Problem?

    Jakarta has the worst traffic in the world, according to a recent study. So, the city is building a huge mass transit system to help people in Jakarta get from Point A to Point B more quickly and easily. But this requires sacrifice because the construction of the system is causing more traffic. More

  • Audio UN Peacekeeping Report Advises Changes

    UN Secretary-General Ban Ki-moon asked for a study on peacekeeping operations. The study gives suggestions to improve United Nations peacekeeping operations around the world. It deals with the responsibility of the peacekeepers, their orders, and what people expect of them. More

  • Audio Kerry Deplores Rights Violation in Eastern Ukraine

    Also, Kerry called for investigation in Nemtsov's death and defended Israel at the UN. Iraqi forces have launched an offensive against Islamic State fighters. And, North Korean has fired missiles into the sea in an apparent protest against joint U.S. and South Korean exercises. More

  • FILE - A man watches a TV news program showing a file picture of a missile launch conducted by North Korea, at Seoul Railway Station in Seoul, South Korea.

    Audio Can North Korea Build More Nuclear Weapons?

    A new report says North Korea could have as many as 100 nuclear weapons by 2020. That includes the 16 to 20 such weapons the report’s writer says the closed country already has. Not everyone agrees North Korea will be able to build that many more nuclear weapons in the next five years. More

Featured Stories

  • FILE - An embryologist works on a petri dish at a London fertility clinic.

    Audio 'Three-Person Babies' Debate Goes Beyond Science and Religion

    Mitochondrial Replacement Therapy uses the genetic material from three people to create babies. The stated purpose of the therapy is to help mothers avoid passing genetic mutations to their babies. Some say MRT will lead to 'designer babies.' Others say it is dangerous, immoral or just wrong. More

  • Steam and smoke is seen over the coal burning power plant in Gelsenkirchen, Germany, on Wednesday, Dec. 16, 2009. Coal power plants are among the biggest producer of CO2, that is supposed to be responsible for climate change.

    Audio Capturing CO2 Is Costly and Difficult

    Most scientists agree that increasing amounts of carbon-dioxide gas in the atmosphere is partly to blame for climate change. Climate change can have a big effect on weather conditions around the world. Scientists are looking for the best and least costly methods for capturing the gas. More

  • Kerry and Declan Reichs (Courtesy Photo)

    Video Choosing to Be a Single Mother

    U.S. officials say birth rates for unmarried women over age 40 have been rising in recent years. In fact, the rate in 2012 was almost 30 percent higher than just five years earlier. There are single mothers by choice. They are generally older, successful, well-educated, and financially secure. More

  • Audio Young Writer’s Plays Explore Race, Identity in America

    Branden Jacobs-Jenkins' latest play 'An Octoroon,' is showing at a theater in New York City. It is based on a 19th Century work by Dion Boucicault. It tells about a white man who falls in love with a woman who is part black. At the time, mixed race marriage was banned in southern US states. More

  • Audio Understanding the Misunderstood Teenage Brain

    A common battle cry of teenagers to adults is, "You just don't understand me!" Well, they might be right. A brain scientist (neuroscientist) and mother to two teenagers says the teenage brain is quite different from the adult brain. She "debunks," or clears up three common myths about teenagers. More

Practice Your Writing

Confessions of an English Learner blog
Confessions of an English Learner blog

 

 

 

Tell us About Our Programs