Can I Spray Roundup on Pollinating Corn?

How It Works

• Glyphosate is the active ingredient in Roundup. It works by preventing a key enzyme within a plant from functioning, which eventually kills the plant. Roundup is a postemergent, nonselective herbicide, which means that it is sprayed onto plants after they emerge from the soil, and it will kill almost any plant that it touches. If sufficient Roundup comes into contact with normal corn stalks at any time, the corn plant will die.

Roundup Ready Plants

• Because Roundup is used so extensively and the possibility exists that crops may accidentally be harmed with it, companies have developed genetically modified corn and soybean strains that are immune to the effects of Roundup. These strains are actively used by many farmers under the name Roundup Ready. According to Indiana University-Purdue University Indianapolis, as of 2003, almost 50 percent of corn and 70 percent of soybeans grown in the U.S. were considered Roundup Ready. Spraying this type of corn when it is pollinating will not hurt it.

Benefits

• Roundup is used on farms because of the benefits it offers. It is not generally toxic to other living things, it does not move through the soil to other locations and it quickly breaks down in the soil to harmless chemicals. Because it is postemergent, it can be sprayed on weeds before vegetable, grass or flower seeds are planted without harm to the seed germination. Roundup also does not affect the woody stems of trees, but if the tree has damage to the bark, Roundup should not be used near it.

How to Use

• All spray herbicides such as Roundup are subject to drifting in the wind when used. It should only be applied when there is no breeze and with a nozzle that is held close to the plants. Use Roundup only when the temperature is 60 to 85 degrees Fahrenheit and when rain is not expected. Normal activity can be resumed after six hours have passed.